<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:9e39988b-7142-4198-9dd7-f1488d106307,g:e87e2b6a-934e-4c58-a991-fad52f196c40-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/Cover" xlink:type="simple" xlink:href="vtvt-20240331.xsd#Cover"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_8370b29b-9499-422f-b831-65291f198c0a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentInformationTable_8370b29b-9499-422f-b831-65291f198c0a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_6ba7a282-d600-485b-8600-7f9d2cab8a3b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_8370b29b-9499-422f-b831-65291f198c0a" xlink:to="loc_us-gaap_StatementClassOfStockAxis_6ba7a282-d600-485b-8600-7f9d2cab8a3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_6ba7a282-d600-485b-8600-7f9d2cab8a3b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6ba7a282-d600-485b-8600-7f9d2cab8a3b" xlink:to="loc_us-gaap_ClassOfStockDomain_6ba7a282-d600-485b-8600-7f9d2cab8a3b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_6fe3c5e9-ff24-4166-bddb-8aa6bed1d6ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6ba7a282-d600-485b-8600-7f9d2cab8a3b" xlink:to="loc_us-gaap_ClassOfStockDomain_6fe3c5e9-ff24-4166-bddb-8aa6bed1d6ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_1187f0e5-141b-453d-a5e8-fb05a3e9e964" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6fe3c5e9-ff24-4166-bddb-8aa6bed1d6ff" xlink:to="loc_us-gaap_CommonClassAMember_1187f0e5-141b-453d-a5e8-fb05a3e9e964" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_0de30bd0-241c-4850-a55f-9f596c24345e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6fe3c5e9-ff24-4166-bddb-8aa6bed1d6ff" xlink:to="loc_us-gaap_CommonClassBMember_0de30bd0-241c-4850-a55f-9f596c24345e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_e603185d-2312-472f-9af7-b893821a07ff" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentType_e603185d-2312-472f-9af7-b893821a07ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_6ac8f1df-80d1-4493-b871-7766e2be043e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentQuarterlyReport_6ac8f1df-80d1-4493-b871-7766e2be043e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_6d81db4c-0a2f-4274-aa35-97c2db17255d" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentPeriodEndDate_6d81db4c-0a2f-4274-aa35-97c2db17255d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_e3cf848b-8684-4fd3-b0c1-2f3889e9b6ad" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentTransitionReport_e3cf848b-8684-4fd3-b0c1-2f3889e9b6ad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_42893466-6534-44e4-be0f-4fdda4f42959" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityFileNumber_42893466-6534-44e4-be0f-4fdda4f42959" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_8ac24cf0-9869-4c40-9474-844b216888f1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityRegistrantName_8ac24cf0-9869-4c40-9474-844b216888f1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_fe9b9241-381a-4c50-897e-93589973b09a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityIncorporationStateCountryCode_fe9b9241-381a-4c50-897e-93589973b09a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_f7325723-24fb-4771-a3ed-bf6edf1199ab" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityTaxIdentificationNumber_f7325723-24fb-4771-a3ed-bf6edf1199ab" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_dcef66cd-0f99-4b03-b136-3492be95105f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityAddressAddressLine1_dcef66cd-0f99-4b03-b136-3492be95105f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_dae91a1d-86f5-4d05-be67-861cf7609a43" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityAddressAddressLine2_dae91a1d-86f5-4d05-be67-861cf7609a43" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_7e4e869f-8f91-447f-8236-126fd1acd5a3" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityAddressCityOrTown_7e4e869f-8f91-447f-8236-126fd1acd5a3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_b9891707-f338-437e-9f48-f2216eae4b21" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityAddressStateOrProvince_b9891707-f338-437e-9f48-f2216eae4b21" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_e4a1b0fd-bff2-4955-be2c-33be6e1ca4c7" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityAddressPostalZipCode_e4a1b0fd-bff2-4955-be2c-33be6e1ca4c7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_d45b8dc8-e607-4f85-b4e9-7f864ab6c59e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_CityAreaCode_d45b8dc8-e607-4f85-b4e9-7f864ab6c59e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_c991d4da-71de-41fd-8962-77d3e3cf815f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_LocalPhoneNumber_c991d4da-71de-41fd-8962-77d3e3cf815f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_ad1f9504-85bc-4d3c-9562-ebc853de3a2b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_Security12bTitle_ad1f9504-85bc-4d3c-9562-ebc853de3a2b" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_8a178d66-6748-40e3-bf16-b7edc32afeb5" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_TradingSymbol_8a178d66-6748-40e3-bf16-b7edc32afeb5" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_d6950100-d6d6-4cb9-a5c5-0f0eff618783" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_SecurityExchangeName_d6950100-d6d6-4cb9-a5c5-0f0eff618783" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_72854954-228d-4276-9a37-5243c14aa19e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityCurrentReportingStatus_72854954-228d-4276-9a37-5243c14aa19e" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_670e7705-68e6-4220-8180-1f2fbf29317a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityInteractiveDataCurrent_670e7705-68e6-4220-8180-1f2fbf29317a" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_b10d3415-d679-4868-832b-4500e77c6ea7" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityFilerCategory_b10d3415-d679-4868-832b-4500e77c6ea7" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_83b325ba-4205-4bf6-b948-0b0aa7683ddb" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntitySmallBusiness_83b325ba-4205-4bf6-b948-0b0aa7683ddb" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_f8cd4ab4-80c1-472a-ae74-07f901eb3690" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityEmergingGrowthCompany_f8cd4ab4-80c1-472a-ae74-07f901eb3690" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_24404b11-216c-4cdb-befd-b5d41734d60d" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityShellCompany_24404b11-216c-4cdb-befd-b5d41734d60d" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_a2a74a91-d7d4-45f4-90a7-fd04833b3876" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_a2a74a91-d7d4-45f4-90a7-fd04833b3876" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_0866c412-14c6-43d6-8ffe-83ca04865909" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_EntityCentralIndexKey_0866c412-14c6-43d6-8ffe-83ca04865909" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_743ef431-f792-48f6-89b6-29f3c19dd00d" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_CurrentFiscalYearEndDate_743ef431-f792-48f6-89b6-29f3c19dd00d" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_1f0eeab9-e082-42f1-92bc-0d8aedc79d05" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentFiscalYearFocus_1f0eeab9-e082-42f1-92bc-0d8aedc79d05" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_76c5135c-1f52-44e3-8d29-2afb133b70e2" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_DocumentFiscalPeriodFocus_76c5135c-1f52-44e3-8d29-2afb133b70e2" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_0dc2f6f2-217f-4169-99e4-003988752124" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_59aa3128-bc8a-4b2c-995c-7bc7f6945e1b" xlink:to="loc_dei_AmendmentFlag_0dc2f6f2-217f-4169-99e4-003988752124" xlink:type="arc" order="29"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/CondensedConsolidatedBalanceSheets" xlink:type="simple" xlink:href="vtvt-20240331.xsd#CondensedConsolidatedBalanceSheets"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_944965d1-c30a-4b41-923d-5c93ab5f2aae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_7c87ea11-3b39-4ccd-8394-e821629d320a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_944965d1-c30a-4b41-923d-5c93ab5f2aae" xlink:to="loc_us-gaap_StatementTable_7c87ea11-3b39-4ccd-8394-e821629d320a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_d9f2831e-3620-467f-8238-3ccc4fcd4df9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_7c87ea11-3b39-4ccd-8394-e821629d320a" xlink:to="loc_us-gaap_StatementClassOfStockAxis_d9f2831e-3620-467f-8238-3ccc4fcd4df9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d9f2831e-3620-467f-8238-3ccc4fcd4df9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d9f2831e-3620-467f-8238-3ccc4fcd4df9" xlink:to="loc_us-gaap_ClassOfStockDomain_d9f2831e-3620-467f-8238-3ccc4fcd4df9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3b431250-e033-4c36-9858-300d1afc4c85" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d9f2831e-3620-467f-8238-3ccc4fcd4df9" xlink:to="loc_us-gaap_ClassOfStockDomain_3b431250-e033-4c36-9858-300d1afc4c85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_cb7d854b-d6c4-4b7c-b2b3-846f7a91bcfe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3b431250-e033-4c36-9858-300d1afc4c85" xlink:to="loc_us-gaap_CommonClassAMember_cb7d854b-d6c4-4b7c-b2b3-846f7a91bcfe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_d2a563a8-d1be-4d41-9343-5daa74116cd8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3b431250-e033-4c36-9858-300d1afc4c85" xlink:to="loc_us-gaap_CommonClassBMember_d2a563a8-d1be-4d41-9343-5daa74116cd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_04f5e59d-cb79-444b-9530-0d041ef64c4c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_944965d1-c30a-4b41-923d-5c93ab5f2aae" xlink:to="loc_us-gaap_AssetsAbstract_04f5e59d-cb79-444b-9530-0d041ef64c4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_04f5e59d-cb79-444b-9530-0d041ef64c4c" xlink:to="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_93458963-732f-47c7-9a77-86ee509a8f4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_93458963-732f-47c7-9a77-86ee509a8f4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_430f7fe6-42fe-4284-99ed-4bd440f6d93b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_430f7fe6-42fe-4284-99ed-4bd440f6d93b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_7acd7bdc-85b5-43e9-9176-224ffb2d4f3c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_7acd7bdc-85b5-43e9-9176-224ffb2d4f3c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsAssetsCurrent_6926dbb2-121d-4737-85f9-c932871b1e76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepositsAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:to="loc_us-gaap_DepositsAssetsCurrent_6926dbb2-121d-4737-85f9-c932871b1e76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_c745521a-f1cb-499c-ab8b-72996be19786" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_08935748-f6b1-4cd0-91c6-81fd786d68e4" xlink:to="loc_us-gaap_AssetsCurrent_c745521a-f1cb-499c-ab8b-72996be19786" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_2bd5a324-b4ea-4747-afcd-0333caa21b5e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_04f5e59d-cb79-444b-9530-0d041ef64c4c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_2bd5a324-b4ea-4747-afcd-0333caa21b5e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_b8800672-5381-4e01-bc7c-44e1650502d5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_04f5e59d-cb79-444b-9530-0d041ef64c4c" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_b8800672-5381-4e01-bc7c-44e1650502d5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_093af396-299d-4486-b103-dd9f21047966" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_04f5e59d-cb79-444b-9530-0d041ef64c4c" xlink:to="loc_us-gaap_Assets_093af396-299d-4486-b103-dd9f21047966" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_944965d1-c30a-4b41-923d-5c93ab5f2aae" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_995973c3-f32a-4a25-a77a-76e97971d034" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_995973c3-f32a-4a25-a77a-76e97971d034" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_eab075ef-3ea7-4f28-8a77-0283c27d1149" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_eab075ef-3ea7-4f28-8a77-0283c27d1149" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_8d82ac2c-7ce7-4bad-a2c0-9275d3aa915f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_8d82ac2c-7ce7-4bad-a2c0-9275d3aa915f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayableCurrent_34468c2c-c1a6-467c-b88a-22fbf0b76ac8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NotesPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:to="loc_us-gaap_NotesPayableCurrent_34468c2c-c1a6-467c-b88a-22fbf0b76ac8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_62744619-a3c1-4d62-ac4e-590d3dca29c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_74c6a53b-4b93-466c-8107-3c919167f511" xlink:to="loc_us-gaap_LiabilitiesCurrent_62744619-a3c1-4d62-ac4e-590d3dca29c7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_a793915e-a00b-4ead-9c95-8e54af63573a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_a793915e-a00b-4ead-9c95-8e54af63573a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_2bc0f472-4801-47ab-908b-7f5129386f41" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_2bc0f472-4801-47ab-908b-7f5129386f41" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_WarrantyLiability_60f9a828-9866-4de7-b70c-aff12bb41aea" xlink:href="vtvt-20240331.xsd#vtvt_WarrantyLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_vtvt_WarrantyLiability_60f9a828-9866-4de7-b70c-aff12bb41aea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_7073a1d8-e29a-4477-b4b1-1e5cef1f04e2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_Liabilities_7073a1d8-e29a-4477-b4b1-1e5cef1f04e2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_1bc29136-0b45-4d30-bded-8a26cd54bd5a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_CommitmentsAndContingencies_1bc29136-0b45-4d30-bded-8a26cd54bd5a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_6aa86e11-c484-474b-8eb2-9796ea630df8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_6aa86e11-c484-474b-8eb2-9796ea630df8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_14e70711-69d5-4e49-8a4f-a90033f7699e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:to="loc_us-gaap_CommonStockValue_14e70711-69d5-4e49-8a4f-a90033f7699e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_1fd1d108-b831-4e29-8491-2b91ce9bd4c5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_1fd1d108-b831-4e29-8491-2b91ce9bd4c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_a2b63980-f0f5-47ae-9e12-ce78c231bd4f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_a2b63980-f0f5-47ae-9e12-ce78c231bd4f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_457f83c1-a29f-430d-961e-6e0c0a475e6e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:to="loc_us-gaap_StockholdersEquity_457f83c1-a29f-430d-961e-6e0c0a475e6e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_8dcfea71-dbdd-47ee-9431-e31dd9898f19" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:to="loc_us-gaap_MinorityInterest_8dcfea71-dbdd-47ee-9431-e31dd9898f19" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_e043c170-0964-4cea-9eab-fdda670db985" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_1e966a89-1604-4947-8427-9b0ccbea37db" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_e043c170-0964-4cea-9eab-fdda670db985" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_3c3d3366-8f51-4b42-a239-95e67705e7b7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_69c5258a-33a6-481f-99c5-ffc1a28d2171" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_3c3d3366-8f51-4b42-a239-95e67705e7b7" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="simple" xlink:href="vtvt-20240331.xsd#CondensedConsolidatedBalanceSheetsParenthetical"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_c385bbdb-e765-4a38-b5a8-f2d9ada75e0c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_f2decbd8-6630-428d-a8d3-f507a63f29ef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_c385bbdb-e765-4a38-b5a8-f2d9ada75e0c" xlink:to="loc_us-gaap_StatementTable_f2decbd8-6630-428d-a8d3-f507a63f29ef" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_b2be2893-ab16-4199-97a0-df326d8c6b49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_f2decbd8-6630-428d-a8d3-f507a63f29ef" xlink:to="loc_us-gaap_StatementClassOfStockAxis_b2be2893-ab16-4199-97a0-df326d8c6b49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_b2be2893-ab16-4199-97a0-df326d8c6b49_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b2be2893-ab16-4199-97a0-df326d8c6b49" xlink:to="loc_us-gaap_ClassOfStockDomain_b2be2893-ab16-4199-97a0-df326d8c6b49_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_226f3399-53db-408d-9c58-997c0eebb5b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b2be2893-ab16-4199-97a0-df326d8c6b49" xlink:to="loc_us-gaap_ClassOfStockDomain_226f3399-53db-408d-9c58-997c0eebb5b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_c147d8ce-02fe-4e08-b85e-b6d340372448" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_226f3399-53db-408d-9c58-997c0eebb5b9" xlink:to="loc_us-gaap_CommonClassAMember_c147d8ce-02fe-4e08-b85e-b6d340372448" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_c38d1797-622e-480b-916b-1aa7268c0ce2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_226f3399-53db-408d-9c58-997c0eebb5b9" xlink:to="loc_us-gaap_CommonClassBMember_c38d1797-622e-480b-916b-1aa7268c0ce2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_b91fc736-3cbb-4876-87a3-1cef7de45a79" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c385bbdb-e765-4a38-b5a8-f2d9ada75e0c" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_b91fc736-3cbb-4876-87a3-1cef7de45a79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_51a873b6-c065-4322-9678-a4ecdfc574bd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c385bbdb-e765-4a38-b5a8-f2d9ada75e0c" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_51a873b6-c065-4322-9678-a4ecdfc574bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_c830f8f1-e46e-4ae9-8ced-078e1159678f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c385bbdb-e765-4a38-b5a8-f2d9ada75e0c" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_c830f8f1-e46e-4ae9-8ced-078e1159678f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/CondensedConsolidatedStatementsofOperationsUnaudited" xlink:type="simple" xlink:href="vtvt-20240331.xsd#CondensedConsolidatedStatementsofOperationsUnaudited"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/CondensedConsolidatedStatementsofOperationsUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_a888cc9b-d245-4768-9ac8-e9a5c9aac0ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_StatementTable_a888cc9b-d245-4768-9ac8-e9a5c9aac0ea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_d115fae7-2999-42e4-ad32-307f8c005a6f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_a888cc9b-d245-4768-9ac8-e9a5c9aac0ea" xlink:to="loc_us-gaap_StatementClassOfStockAxis_d115fae7-2999-42e4-ad32-307f8c005a6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d115fae7-2999-42e4-ad32-307f8c005a6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d115fae7-2999-42e4-ad32-307f8c005a6f" xlink:to="loc_us-gaap_ClassOfStockDomain_d115fae7-2999-42e4-ad32-307f8c005a6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3da11ab2-5621-4e7e-a8a5-850f5ceca800" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d115fae7-2999-42e4-ad32-307f8c005a6f" xlink:to="loc_us-gaap_ClassOfStockDomain_3da11ab2-5621-4e7e-a8a5-850f5ceca800" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_5a0411ff-fe2f-49da-9314-e9a6eba5be3c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3da11ab2-5621-4e7e-a8a5-850f5ceca800" xlink:to="loc_us-gaap_CommonClassAMember_5a0411ff-fe2f-49da-9314-e9a6eba5be3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_16070e44-a51e-4c2c-a8c5-6cd708e1a03b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_a888cc9b-d245-4768-9ac8-e9a5c9aac0ea" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_16070e44-a51e-4c2c-a8c5-6cd708e1a03b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_16070e44-a51e-4c2c-a8c5-6cd708e1a03b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_16070e44-a51e-4c2c-a8c5-6cd708e1a03b" xlink:to="loc_us-gaap_RelatedPartyDomain_16070e44-a51e-4c2c-a8c5-6cd708e1a03b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_a2e0e25b-c142-488c-8b95-6206258038d0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_16070e44-a51e-4c2c-a8c5-6cd708e1a03b" xlink:to="loc_us-gaap_RelatedPartyDomain_a2e0e25b-c142-488c-8b95-6206258038d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonrelatedPartyMember_27389f15-923a-45ae-99e9-7e876eced3d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonrelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_a2e0e25b-c142-488c-8b95-6206258038d0" xlink:to="loc_us-gaap_NonrelatedPartyMember_27389f15-923a-45ae-99e9-7e876eced3d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_ba5874ec-522b-497f-84ab-9ad75a2ef993" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_a2e0e25b-c142-488c-8b95-6206258038d0" xlink:to="loc_us-gaap_RelatedPartyMember_ba5874ec-522b-497f-84ab-9ad75a2ef993" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0f9e7977-1039-4d4c-9e87-59d71eef23a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_0f9e7977-1039-4d4c-9e87-59d71eef23a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_a6b4ac8a-32d1-460e-9bc9-f507898dc98f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_OperatingExpensesAbstract_a6b4ac8a-32d1-460e-9bc9-f507898dc98f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_e3200166-ac90-4004-ab3b-f90dfd63670f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a6b4ac8a-32d1-460e-9bc9-f507898dc98f" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_e3200166-ac90-4004-ab3b-f90dfd63670f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_d5c898ed-64bd-4ab8-89ec-1409c2ef44c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a6b4ac8a-32d1-460e-9bc9-f507898dc98f" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_d5c898ed-64bd-4ab8-89ec-1409c2ef44c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_f84ef86f-d389-456f-97bc-3951dccc9680" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a6b4ac8a-32d1-460e-9bc9-f507898dc98f" xlink:to="loc_us-gaap_OperatingExpenses_f84ef86f-d389-456f-97bc-3951dccc9680" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_116e5938-bf28-48b1-9d6a-62d1b3b86c27" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_OperatingIncomeLoss_116e5938-bf28-48b1-9d6a-62d1b3b86c27" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_f913a8a7-9a54-48f4-8e9e-73c83fbf17c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_f913a8a7-9a54-48f4-8e9e-73c83fbf17c6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_52d3843a-109e-4756-91a8-6c02c9b58ef7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_InvestmentIncomeInterest_52d3843a-109e-4756-91a8-6c02c9b58ef7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_744d8b9b-336f-4175-ad42-8f39bfb618a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_744d8b9b-336f-4175-ad42-8f39bfb618a8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_50a85357-0a3c-490f-9b48-d3f787d1fa78" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_50a85357-0a3c-490f-9b48-d3f787d1fa78" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_86d0914d-cb64-4629-ac26-d3f939d74a64" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_ProfitLoss_86d0914d-cb64-4629-ac26-d3f939d74a64" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_21f92a63-d767-4b37-8b70-4dc980ea6653" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_21f92a63-d767-4b37-8b70-4dc980ea6653" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_2db5193f-576b-4a23-86b3-f064688aef4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_NetIncomeLoss_2db5193f-576b-4a23-86b3-f064688aef4a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_d9f9850a-81cc-439a-8371-af04ecf2ff84" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_d9f9850a-81cc-439a-8371-af04ecf2ff84" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_36b3af24-5c50-462e-b886-708daa5bd637" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_EarningsPerShareBasic_36b3af24-5c50-462e-b886-708daa5bd637" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_8ecf210f-bc4e-4c55-8ae6-45cda2bcd3b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_EarningsPerShareDiluted_8ecf210f-bc4e-4c55-8ae6-45cda2bcd3b3" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_055eb083-de6a-42db-acb7-a601c529715b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_055eb083-de6a-42db-acb7-a601c529715b" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_70fd9501-b3a0-4dd4-9774-7a2b2864db0a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_18d1c0de-84b7-4c43-9bb5-96aa76db002b" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_70fd9501-b3a0-4dd4-9774-7a2b2864db0a" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/CondensedConsolidatedStatementofChangesinRedeemableNoncontrollingInterestandStockholdersDeficitUnaudited" xlink:type="simple" xlink:href="vtvt-20240331.xsd#CondensedConsolidatedStatementofChangesinRedeemableNoncontrollingInterestandStockholdersDeficitUnaudited"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/CondensedConsolidatedStatementofChangesinRedeemableNoncontrollingInterestandStockholdersDeficitUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_e6e4087a-e562-418c-a5d5-8e61ef678e16" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_30a3c565-08ae-4360-be85-20b8720a5cc5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_e6e4087a-e562-418c-a5d5-8e61ef678e16" xlink:to="loc_us-gaap_StatementTable_30a3c565-08ae-4360-be85-20b8720a5cc5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d987af66-e42d-479d-9799-812c73fa50fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_30a3c565-08ae-4360-be85-20b8720a5cc5" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d987af66-e42d-479d-9799-812c73fa50fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d987af66-e42d-479d-9799-812c73fa50fe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d987af66-e42d-479d-9799-812c73fa50fe" xlink:to="loc_us-gaap_EquityComponentDomain_d987af66-e42d-479d-9799-812c73fa50fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d987af66-e42d-479d-9799-812c73fa50fe" xlink:to="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_e2331e25-33fd-411f-8712-93245740cc5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:to="loc_us-gaap_CommonStockMember_e2331e25-33fd-411f-8712-93245740cc5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_3431c014-b96d-425e-ad82-c8390b62420d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_3431c014-b96d-425e-ad82-c8390b62420d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_7199589f-ba85-4d5a-9866-510ba39b9d15" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:to="loc_us-gaap_RetainedEarningsMember_7199589f-ba85-4d5a-9866-510ba39b9d15" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_bb709fe0-34c3-4c7d-84f4-f9ed2f3fca6a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:to="loc_us-gaap_ParentMember_bb709fe0-34c3-4c7d-84f4-f9ed2f3fca6a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_d49a67b9-22be-4f7b-9b3e-ebfbb5a03d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_7fdb4fb3-e0ff-4ac2-86c6-c39987aa4ca2" xlink:to="loc_us-gaap_NoncontrollingInterestMember_d49a67b9-22be-4f7b-9b3e-ebfbb5a03d7b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_6a234cbe-f1da-4b53-b135-c61b15e6af42" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_30a3c565-08ae-4360-be85-20b8720a5cc5" xlink:to="loc_us-gaap_StatementClassOfStockAxis_6a234cbe-f1da-4b53-b135-c61b15e6af42" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_6a234cbe-f1da-4b53-b135-c61b15e6af42_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6a234cbe-f1da-4b53-b135-c61b15e6af42" xlink:to="loc_us-gaap_ClassOfStockDomain_6a234cbe-f1da-4b53-b135-c61b15e6af42_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_bcf123b2-e7e9-4f3e-aeec-e9672475c7bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_6a234cbe-f1da-4b53-b135-c61b15e6af42" xlink:to="loc_us-gaap_ClassOfStockDomain_bcf123b2-e7e9-4f3e-aeec-e9672475c7bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_RedeemableNoncontrollingInterestsMember_32132d3c-7dec-451d-b07a-6f3842258bd6" xlink:href="vtvt-20240331.xsd#vtvt_RedeemableNoncontrollingInterestsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_bcf123b2-e7e9-4f3e-aeec-e9672475c7bb" xlink:to="loc_vtvt_RedeemableNoncontrollingInterestsMember_32132d3c-7dec-451d-b07a-6f3842258bd6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_848ef543-c0c6-4ab8-a128-dce9a1022a5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_bcf123b2-e7e9-4f3e-aeec-e9672475c7bb" xlink:to="loc_us-gaap_CommonClassAMember_848ef543-c0c6-4ab8-a128-dce9a1022a5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_86ad30c6-f9a8-40e1-8e78-e06814b3d94c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_bcf123b2-e7e9-4f3e-aeec-e9672475c7bb" xlink:to="loc_us-gaap_CommonClassBMember_86ad30c6-f9a8-40e1-8e78-e06814b3d94c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_e6e4087a-e562-418c-a5d5-8e61ef678e16" xlink:to="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_6345ce0a-7280-4838-a555-1138a6ede6f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_6345ce0a-7280-4838-a555-1138a6ede6f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityNetIncome_f7579095-b2a7-4ca0-97cf-2efd02f68874" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TemporaryEquityNetIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:to="loc_us-gaap_TemporaryEquityNetIncome_f7579095-b2a7-4ca0-97cf-2efd02f68874" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestChangeInRedemptionValue_6440d476-b6e7-42c9-a613-4424d2bc1e0c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestChangeInRedemptionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:to="loc_us-gaap_MinorityInterestChangeInRedemptionValue_6440d476-b6e7-42c9-a613-4424d2bc1e0c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationsOfTemporaryToPermanentEquity_c0fd42ab-5547-4829-93cf-eb85191130ab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReclassificationsOfTemporaryToPermanentEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:to="loc_us-gaap_ReclassificationsOfTemporaryToPermanentEquity_c0fd42ab-5547-4829-93cf-eb85191130ab" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_17cf8e54-9a8f-4cbe-a075-f1ccc11339ec" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_0a27cf42-1f87-43f0-9d68-52eaf87c7606" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_17cf8e54-9a8f-4cbe-a075-f1ccc11339ec" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_af6ef171-158e-420d-889a-fb33752998b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_e6e4087a-e562-418c-a5d5-8e61ef678e16" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_ef87f1ce-a078-4b32-abd4-f8d87532be81" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_ef87f1ce-a078-4b32-abd4-f8d87532be81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7d69a863-9fef-494a-98b2-6b6f81ccfd58" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7d69a863-9fef-494a-98b2-6b6f81ccfd58" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_c4d483dd-dab2-4e4e-ac00-bd7e0d896d0b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_NetIncomeLoss_c4d483dd-dab2-4e4e-ac00-bd7e0d896d0b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ChangeInRedemptionValueOfNoncontrollingInterest_d3b8466e-1712-4203-a884-748e54385814" xlink:href="vtvt-20240331.xsd#vtvt_ChangeInRedemptionValueOfNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_vtvt_ChangeInRedemptionValueOfNoncontrollingInterest_d3b8466e-1712-4203-a884-748e54385814" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationsOfTemporaryToPermanentEquity_3605b0b2-4229-4a98-838d-b42ae465cb99" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReclassificationsOfTemporaryToPermanentEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_cb5a1965-1eac-4c56-a25c-efaf5e21c5cf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_cb5a1965-1eac-4c56-a25c-efaf5e21c5cf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_6d48730a-66dc-43ca-8ee6-9ec855fbddad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_6d48730a-66dc-43ca-8ee6-9ec855fbddad" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_8486d88b-10bd-435b-a29f-738082889d91" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_8486d88b-10bd-435b-a29f-738082889d91" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest_9c2e8aa0-386d-4f19-89c1-059a5e3e9a20" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_0580a020-048f-49f5-94da-80967fc814e3" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest_9c2e8aa0-386d-4f19-89c1-059a5e3e9a20" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_c4fcf2c4-7c8c-40e7-bdb6-8a8f4a25af76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_0c1a378f-bd8d-49c3-95ec-5dd4c30bd52a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/DescriptionofBusinessandBasisofPresentationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#DescriptionofBusinessandBasisofPresentationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/DescriptionofBusinessandBasisofPresentationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:href="vtvt-20240331.xsd#vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable_3dfdddba-bd9f-44bc-a855-e21c7f5fea7a" xlink:href="vtvt-20240331.xsd#vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable_3dfdddba-bd9f-44bc-a855-e21c7f5fea7a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_65fb679d-c6e6-471f-a91d-70f0a688dfc1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable_3dfdddba-bd9f-44bc-a855-e21c7f5fea7a" xlink:to="loc_dei_LegalEntityAxis_65fb679d-c6e6-471f-a91d-70f0a688dfc1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_65fb679d-c6e6-471f-a91d-70f0a688dfc1_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_65fb679d-c6e6-471f-a91d-70f0a688dfc1" xlink:to="loc_dei_EntityDomain_65fb679d-c6e6-471f-a91d-70f0a688dfc1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_32d1270a-37a5-42bb-bbca-1d6b4acd7f27" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_65fb679d-c6e6-471f-a91d-70f0a688dfc1" xlink:to="loc_dei_EntityDomain_32d1270a-37a5-42bb-bbca-1d6b4acd7f27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_VTvLLCMember_d81cbd87-4cef-4f20-ba62-547fa498826f" xlink:href="vtvt-20240331.xsd#vtvt_VTvLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_32d1270a-37a5-42bb-bbca-1d6b4acd7f27" xlink:to="loc_vtvt_VTvLLCMember_d81cbd87-4cef-4f20-ba62-547fa498826f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_4c5bda18-ddd4-4776-b1fb-78d21dbd403a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable_3dfdddba-bd9f-44bc-a855-e21c7f5fea7a" xlink:to="loc_us-gaap_StatementClassOfStockAxis_4c5bda18-ddd4-4776-b1fb-78d21dbd403a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_4c5bda18-ddd4-4776-b1fb-78d21dbd403a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_4c5bda18-ddd4-4776-b1fb-78d21dbd403a" xlink:to="loc_us-gaap_ClassOfStockDomain_4c5bda18-ddd4-4776-b1fb-78d21dbd403a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_9cd877d8-20b4-4aa5-8412-b571b86562c0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_4c5bda18-ddd4-4776-b1fb-78d21dbd403a" xlink:to="loc_us-gaap_ClassOfStockDomain_9cd877d8-20b4-4aa5-8412-b571b86562c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_ec20848b-b924-42d3-bf89-efccb4f958d2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_9cd877d8-20b4-4aa5-8412-b571b86562c0" xlink:to="loc_us-gaap_CommonClassAMember_ec20848b-b924-42d3-bf89-efccb4f958d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_ce264bb6-6df1-40ae-8866-035b12245354" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_9cd877d8-20b4-4aa5-8412-b571b86562c0" xlink:to="loc_us-gaap_CommonClassBMember_ce264bb6-6df1-40ae-8866-035b12245354" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_c80a9370-a318-41ac-ad51-49cbb62bafe1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable_3dfdddba-bd9f-44bc-a855-e21c7f5fea7a" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_c80a9370-a318-41ac-ad51-49cbb62bafe1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_c80a9370-a318-41ac-ad51-49cbb62bafe1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_c80a9370-a318-41ac-ad51-49cbb62bafe1" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_c80a9370-a318-41ac-ad51-49cbb62bafe1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_dcb16520-680c-43b7-8641-1ac73566dde9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_c80a9370-a318-41ac-ad51-49cbb62bafe1" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_dcb16520-680c-43b7-8641-1ac73566dde9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivatePlacementMember_9523ee40-d5d9-489f-83ef-7061d7091b35" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrivatePlacementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_dcb16520-680c-43b7-8641-1ac73566dde9" xlink:to="loc_us-gaap_PrivatePlacementMember_9523ee40-d5d9-489f-83ef-7061d7091b35" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_TDCowenSalesAgreementMember_d731dbfe-9168-4878-84bd-d3512a34f3e3" xlink:href="vtvt-20240331.xsd#vtvt_TDCowenSalesAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_dcb16520-680c-43b7-8641-1ac73566dde9" xlink:to="loc_vtvt_TDCowenSalesAgreementMember_d731dbfe-9168-4878-84bd-d3512a34f3e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_707c4904-3f48-4751-81f3-67c94586f5e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsTable_3dfdddba-bd9f-44bc-a855-e21c7f5fea7a" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_707c4904-3f48-4751-81f3-67c94586f5e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_707c4904-3f48-4751-81f3-67c94586f5e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_707c4904-3f48-4751-81f3-67c94586f5e5" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_707c4904-3f48-4751-81f3-67c94586f5e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_5f5f1a85-60dd-4f02-97ee-d629675f974c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_707c4904-3f48-4751-81f3-67c94586f5e5" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_5f5f1a85-60dd-4f02-97ee-d629675f974c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PrivatePlacementPreFundedWarrantsMember_92ecdb7e-3193-468b-a549-b75cc93ae3d8" xlink:href="vtvt-20240331.xsd#vtvt_PrivatePlacementPreFundedWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_5f5f1a85-60dd-4f02-97ee-d629675f974c" xlink:to="loc_vtvt_PrivatePlacementPreFundedWarrantsMember_92ecdb7e-3193-468b-a549-b75cc93ae3d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PercentageOfNonVotingEconomicInterest_df67b265-d110-4763-889d-5958dc526916" xlink:href="vtvt-20240331.xsd#vtvt_PercentageOfNonVotingEconomicInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_PercentageOfNonVotingEconomicInterest_df67b265-d110-4763-889d-5958dc526916" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PercentageOfNonVotingEconomicInterestByParent_d3edf3cb-cb1c-4d7e-bd99-aa1137d6de71" xlink:href="vtvt-20240331.xsd#vtvt_PercentageOfNonVotingEconomicInterestByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_PercentageOfNonVotingEconomicInterestByParent_d3edf3cb-cb1c-4d7e-bd99-aa1137d6de71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_50b06e68-1a3e-440d-b4f2-7945b14dbbe3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_50b06e68-1a3e-440d-b4f2-7945b14dbbe3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_dafe838f-2a9b-49a7-b862-c3838a7f6786" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_dafe838f-2a9b-49a7-b862-c3838a7f6786" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_64f7879f-d508-4a8c-bde3-98b69ce70d32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_64f7879f-d508-4a8c-bde3-98b69ce70d32" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_7753f1e5-fe0e-4766-bbc5-9dc577c2c594" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_7753f1e5-fe0e-4766-bbc5-9dc577c2c594" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_2ac068ca-05a9-4a03-bc13-e44f59f83b0c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_2ac068ca-05a9-4a03-bc13-e44f59f83b0c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_19d70e57-86bf-47d6-814c-e85291c9f595" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_19d70e57-86bf-47d6-814c-e85291c9f595" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_d57e4d3d-c6e2-4383-8b74-91dcb3adb027" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_d57e4d3d-c6e2-4383-8b74-91dcb3adb027" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPrivatePlacement_c5cdce35-d292-4850-bf3a-2358152e0b48" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPrivatePlacement_c5cdce35-d292-4850-bf3a-2358152e0b48" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementShares_e23fa201-a3d0-4f6c-b34c-b4d6d818ed70" xlink:href="vtvt-20240331.xsd#vtvt_CommonStockParOrStatedValueOfPrivatePlacementShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementShares_e23fa201-a3d0-4f6c-b34c-b4d6d818ed70" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementPreFundedWarrantsShares_289d30b4-a5d8-4de8-b617-9b04678b7b60" xlink:href="vtvt-20240331.xsd#vtvt_CommonStockParOrStatedValueOfPrivatePlacementPreFundedWarrantsShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementPreFundedWarrantsShares_289d30b4-a5d8-4de8-b617-9b04678b7b60" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockAggregateOfferingPrice_483b2a4b-4fab-449b-a884-7bde17a49035" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockAggregateOfferingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_SaleOfStockAggregateOfferingPrice_483b2a4b-4fab-449b-a884-7bde17a49035" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_EntityPublicFloatThreshold_2680f0c0-805d-48d8-9cd1-fda1f461e03a" xlink:href="vtvt-20240331.xsd#vtvt_EntityPublicFloatThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_EntityPublicFloatThreshold_2680f0c0-805d-48d8-9cd1-fda1f461e03a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockMaximumSecuritiesToBeSoldPercentOfPublicFloat_0aebae1b-fba0-41cc-abd3-eb9aa0e132ee" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockMaximumSecuritiesToBeSoldPercentOfPublicFloat"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems_d97971d7-aa7d-4411-9978-6d675f9a1a5a" xlink:to="loc_vtvt_SaleOfStockMaximumSecuritiesToBeSoldPercentOfPublicFloat_0aebae1b-fba0-41cc-abd3-eb9aa0e132ee" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/SummaryofSignificantAccountingPoliciesAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#SummaryofSignificantAccountingPoliciesAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/SummaryofSignificantAccountingPoliciesAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SummaryOfSignificantAccountingPoliciesLineItems_feb17335-4968-4678-a61f-d11f944431d7" xlink:href="vtvt-20240331.xsd#vtvt_SummaryOfSignificantAccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SummaryOfSignificantAccountingPoliciesTable_705bc91a-c487-438d-8277-5c17518ecb37" xlink:href="vtvt-20240331.xsd#vtvt_SummaryOfSignificantAccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_vtvt_SummaryOfSignificantAccountingPoliciesLineItems_feb17335-4968-4678-a61f-d11f944431d7" xlink:to="loc_vtvt_SummaryOfSignificantAccountingPoliciesTable_705bc91a-c487-438d-8277-5c17518ecb37" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_378c0dd8-d7a3-4720-bca1-03b322b22077" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_SummaryOfSignificantAccountingPoliciesTable_705bc91a-c487-438d-8277-5c17518ecb37" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_378c0dd8-d7a3-4720-bca1-03b322b22077" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_378c0dd8-d7a3-4720-bca1-03b322b22077_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_378c0dd8-d7a3-4720-bca1-03b322b22077" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_378c0dd8-d7a3-4720-bca1-03b322b22077_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7c6fc14e-c26c-4a73-bf17-54d7dbf4edfc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_378c0dd8-d7a3-4720-bca1-03b322b22077" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7c6fc14e-c26c-4a73-bf17-54d7dbf4edfc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_0869ed30-82ce-4233-923c-51d87e3fd0e8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7c6fc14e-c26c-4a73-bf17-54d7dbf4edfc" xlink:to="loc_us-gaap_SalesRevenueNetMember_0869ed30-82ce-4233-923c-51d87e3fd0e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_2f594ce8-6618-426c-a6cc-7384a08d5a61" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_SummaryOfSignificantAccountingPoliciesTable_705bc91a-c487-438d-8277-5c17518ecb37" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_2f594ce8-6618-426c-a6cc-7384a08d5a61" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_2f594ce8-6618-426c-a6cc-7384a08d5a61_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_2f594ce8-6618-426c-a6cc-7384a08d5a61" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_2f594ce8-6618-426c-a6cc-7384a08d5a61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_21c4f98d-e201-4f60-8a4f-2bdd58d4c8b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_2f594ce8-6618-426c-a6cc-7384a08d5a61" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_21c4f98d-e201-4f60-8a4f-2bdd58d4c8b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_097f6f48-f610-48cd-a540-a3a1bc704f01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_21c4f98d-e201-4f60-8a4f-2bdd58d4c8b0" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_097f6f48-f610-48cd-a540-a3a1bc704f01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_e6500b30-8fb5-411e-9321-12f85ff15b4e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_SummaryOfSignificantAccountingPoliciesTable_705bc91a-c487-438d-8277-5c17518ecb37" xlink:to="loc_srt_MajorCustomersAxis_e6500b30-8fb5-411e-9321-12f85ff15b4e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_e6500b30-8fb5-411e-9321-12f85ff15b4e_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_e6500b30-8fb5-411e-9321-12f85ff15b4e" xlink:to="loc_srt_NameOfMajorCustomerDomain_e6500b30-8fb5-411e-9321-12f85ff15b4e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_4aa54164-0419-4f0a-b8d9-9677b7513b39" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_e6500b30-8fb5-411e-9321-12f85ff15b4e" xlink:to="loc_srt_NameOfMajorCustomerDomain_4aa54164-0419-4f0a-b8d9-9677b7513b39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_OneCustomerMember_a88b9d46-51cc-4b00-94d9-24fa8489c626" xlink:href="vtvt-20240331.xsd#vtvt_OneCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_4aa54164-0419-4f0a-b8d9-9677b7513b39" xlink:to="loc_vtvt_OneCustomerMember_a88b9d46-51cc-4b00-94d9-24fa8489c626" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_899a03fd-6a63-4847-89c9-853ea67d234f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_SummaryOfSignificantAccountingPoliciesLineItems_feb17335-4968-4678-a61f-d11f944431d7" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_899a03fd-6a63-4847-89c9-853ea67d234f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/CollaborationAgreementsAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#CollaborationAgreementsAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/CollaborationAgreementsAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_b1891b4e-13e8-4892-840d-185865cd46d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:to="loc_us-gaap_TypeOfArrangementAxis_b1891b4e-13e8-4892-840d-185865cd46d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_b1891b4e-13e8-4892-840d-185865cd46d9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_b1891b4e-13e8-4892-840d-185865cd46d9" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_b1891b4e-13e8-4892-840d-185865cd46d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_bc2da76a-ec21-44ae-8afc-3ede9f9bcbd0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_b1891b4e-13e8-4892-840d-185865cd46d9" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_bc2da76a-ec21-44ae-8afc-3ede9f9bcbd0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_G2InvestmentsPurchaseAgreementAndCognaCollaborativeAndLicenseAgreementMember_a38336c6-41ce-4c8a-b332-4e781193f407" xlink:href="vtvt-20240331.xsd#vtvt_G2InvestmentsPurchaseAgreementAndCognaCollaborativeAndLicenseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_bc2da76a-ec21-44ae-8afc-3ede9f9bcbd0" xlink:to="loc_vtvt_G2InvestmentsPurchaseAgreementAndCognaCollaborativeAndLicenseAgreementMember_a38336c6-41ce-4c8a-b332-4e781193f407" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollaborativeArrangementMember_60743ff9-ee05-4933-9b2a-61f8378362bc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CollaborativeArrangementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_bc2da76a-ec21-44ae-8afc-3ede9f9bcbd0" xlink:to="loc_us-gaap_CollaborativeArrangementMember_60743ff9-ee05-4933-9b2a-61f8378362bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_354daaf2-99b7-42ca-9958-24410a79081a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:to="loc_dei_LegalEntityAxis_354daaf2-99b7-42ca-9958-24410a79081a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_354daaf2-99b7-42ca-9958-24410a79081a_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_354daaf2-99b7-42ca-9958-24410a79081a" xlink:to="loc_dei_EntityDomain_354daaf2-99b7-42ca-9958-24410a79081a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_6a5b6b8f-fb31-4b98-9bd8-ed944b58c2e0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_354daaf2-99b7-42ca-9958-24410a79081a" xlink:to="loc_dei_EntityDomain_6a5b6b8f-fb31-4b98-9bd8-ed944b58c2e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_JDRFInternationalMember_155d9d77-ddb4-472a-8900-eb29d40c19c1" xlink:href="vtvt-20240331.xsd#vtvt_JDRFInternationalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_6a5b6b8f-fb31-4b98-9bd8-ed944b58c2e0" xlink:to="loc_vtvt_JDRFInternationalMember_155d9d77-ddb4-472a-8900-eb29d40c19c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_NewsoaraBiopharmaCoLtdMember_34266589-fd99-4541-8b7b-d3e2720e3a33" xlink:href="vtvt-20240331.xsd#vtvt_NewsoaraBiopharmaCoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_6a5b6b8f-fb31-4b98-9bd8-ed944b58c2e0" xlink:to="loc_vtvt_NewsoaraBiopharmaCoLtdMember_34266589-fd99-4541-8b7b-d3e2720e3a33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_767ff6ee-afc0-409f-a55f-837010919b66" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:to="loc_srt_CounterpartyNameAxis_767ff6ee-afc0-409f-a55f-837010919b66" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_767ff6ee-afc0-409f-a55f-837010919b66_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_767ff6ee-afc0-409f-a55f-837010919b66" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_767ff6ee-afc0-409f-a55f-837010919b66_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2d79113f-2ea2-4257-a2ae-e666a2f8c273" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_767ff6ee-afc0-409f-a55f-837010919b66" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2d79113f-2ea2-4257-a2ae-e666a2f8c273" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_G42InvestmentsMember_b8656cba-53e5-4ff3-9838-5ddbfb0bdd9b" xlink:href="vtvt-20240331.xsd#vtvt_G42InvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2d79113f-2ea2-4257-a2ae-e666a2f8c273" xlink:to="loc_vtvt_G42InvestmentsMember_b8656cba-53e5-4ff3-9838-5ddbfb0bdd9b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CognaMember_85fc33e3-8cf5-44e5-aefe-dc3e1aa251d0" xlink:href="vtvt-20240331.xsd#vtvt_CognaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2d79113f-2ea2-4257-a2ae-e666a2f8c273" xlink:to="loc_vtvt_CognaMember_85fc33e3-8cf5-44e5-aefe-dc3e1aa251d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_NewsoaraBiopharmaCoLtdMember_3b11f94d-6540-453a-bf13-6ee29ff52710" xlink:href="vtvt-20240331.xsd#vtvt_NewsoaraBiopharmaCoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_2d79113f-2ea2-4257-a2ae-e666a2f8c273" xlink:to="loc_vtvt_NewsoaraBiopharmaCoLtdMember_3b11f94d-6540-453a-bf13-6ee29ff52710" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_ed6bc4fc-9467-473d-a00a-c03f11c68fff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_ed6bc4fc-9467-473d-a00a-c03f11c68fff" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_ed6bc4fc-9467-473d-a00a-c03f11c68fff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_ed6bc4fc-9467-473d-a00a-c03f11c68fff" xlink:to="loc_us-gaap_ClassOfStockDomain_ed6bc4fc-9467-473d-a00a-c03f11c68fff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_6ca1f365-0a56-4993-bca4-068c2d99fcd8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_ed6bc4fc-9467-473d-a00a-c03f11c68fff" xlink:to="loc_us-gaap_ClassOfStockDomain_6ca1f365-0a56-4993-bca4-068c2d99fcd8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_b00c21d2-6b51-4047-b407-14b40023ea93" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_6ca1f365-0a56-4993-bca4-068c2d99fcd8" xlink:to="loc_us-gaap_CommonClassAMember_b00c21d2-6b51-4047-b407-14b40023ea93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_b20a82db-be09-4a46-b32a-65a092bd87c0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_8e343dd2-1310-4731-8997-b2799c04223e" xlink:to="loc_srt_ProductOrServiceAxis_b20a82db-be09-4a46-b32a-65a092bd87c0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_b20a82db-be09-4a46-b32a-65a092bd87c0_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_b20a82db-be09-4a46-b32a-65a092bd87c0" xlink:to="loc_srt_ProductsAndServicesDomain_b20a82db-be09-4a46-b32a-65a092bd87c0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_e8af1a1c-949e-4bbb-9488-db8ab691f382" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_b20a82db-be09-4a46-b32a-65a092bd87c0" xlink:to="loc_srt_ProductsAndServicesDomain_e8af1a1c-949e-4bbb-9488-db8ab691f382" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_LicenseAndTechnologyTransferServicesMember_a4a4aad0-5778-4ebe-b7e7-1d4a7811510a" xlink:href="vtvt-20240331.xsd#vtvt_LicenseAndTechnologyTransferServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_e8af1a1c-949e-4bbb-9488-db8ab691f382" xlink:to="loc_vtvt_LicenseAndTechnologyTransferServicesMember_a4a4aad0-5778-4ebe-b7e7-1d4a7811510a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1977d73a-8cbe-4288-bd2a-3ff2458b1fce" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1977d73a-8cbe-4288-bd2a-3ff2458b1fce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_68079e92-cfa5-4e21-8407-7dcf133cb359" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_68079e92-cfa5-4e21-8407-7dcf133cb359" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockConsiderationReceivedOnTransactionGross_c1339d61-688b-4fa6-8af5-4a0dc516d906" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockConsiderationReceivedOnTransactionGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_SaleOfStockConsiderationReceivedOnTransactionGross_c1339d61-688b-4fa6-8af5-4a0dc516d906" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_1c41f0b2-2c61-4c5f-9dd1-f1b5f35b8b89" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_1c41f0b2-2c61-4c5f-9dd1-f1b5f35b8b89" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_a6d661b0-cc87-46a9-b89f-5cfe478e7644" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsNotesAndLoansReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_a6d661b0-cc87-46a9-b89f-5cfe478e7644" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromCollectionOfNotesReceivable_c4508895-440f-40f6-b23c-9100168c32a6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromCollectionOfNotesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_ProceedsFromCollectionOfNotesReceivable_c4508895-440f-40f6-b23c-9100168c32a6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_NotesReceivableDiscountRate_502a1218-2494-42eb-ba2f-6acbbafe3ce9" xlink:href="vtvt-20240331.xsd#vtvt_NotesReceivableDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_NotesReceivableDiscountRate_502a1218-2494-42eb-ba2f-6acbbafe3ce9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_49f901af-0ba3-4985-b2c9-5fa0d83b598f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_49f901af-0ba3-4985-b2c9-5fa0d83b598f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CollaborativeArrangementContingentConsiderationTransferredAggregateShareValue_6ed614e3-950f-4082-9c69-d96038dc1179" xlink:href="vtvt-20240331.xsd#vtvt_CollaborativeArrangementContingentConsiderationTransferredAggregateShareValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_CollaborativeArrangementContingentConsiderationTransferredAggregateShareValue_6ed614e3-950f-4082-9c69-d96038dc1179" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CollaborateArrangementContingentConsiderationTransferredCash_2155c7ff-ed76-4cad-bdcd-0e062ed91fb4" xlink:href="vtvt-20240331.xsd#vtvt_CollaborateArrangementContingentConsiderationTransferredCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_CollaborateArrangementContingentConsiderationTransferredCash_2155c7ff-ed76-4cad-bdcd-0e062ed91fb4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CollaborativeArrangementRoyaltiesReceivablePeriod_af82b3b1-8738-4eca-8dd3-c92d863bae82" xlink:href="vtvt-20240331.xsd#vtvt_CollaborativeArrangementRoyaltiesReceivablePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_CollaborativeArrangementRoyaltiesReceivablePeriod_af82b3b1-8738-4eca-8dd3-c92d863bae82" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValueOutstanding_1cf9ead3-d140-4226-9553-0beb97479068" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValueOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_CommonStockValueOutstanding_1cf9ead3-d140-4226-9553-0beb97479068" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_a4a8ea54-2487-4304-b704-1df1b52c47b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_SharePrice_a4a8ea54-2487-4304-b704-1df1b52c47b2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_2c8e2b06-c23c-4359-9e3a-76424a6c0862" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_2c8e2b06-c23c-4359-9e3a-76424a6c0862" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CollaborativeArrangementNoteReceivableDiscountPaid_f258ac29-d708-4b82-9ab0-ac880f49de9c" xlink:href="vtvt-20240331.xsd#vtvt_CollaborativeArrangementNoteReceivableDiscountPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_CollaborativeArrangementNoteReceivableDiscountPaid_f258ac29-d708-4b82-9ab0-ac880f49de9c" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromCollaborativeArrangementExcludingRevenueFromContractWithCustomer_8c43158b-e75c-43c3-9ff8-eab76a92f5d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromCollaborativeArrangementExcludingRevenueFromContractWithCustomer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_RevenueFromCollaborativeArrangementExcludingRevenueFromContractWithCustomer_8c43158b-e75c-43c3-9ff8-eab76a92f5d6" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2642e8df-32df-4844-b7ce-0a073a8257a1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2642e8df-32df-4844-b7ce-0a073a8257a1" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFairValueDisclosure_5fb6ee7f-5e2e-467e-aaf4-aa973be7d376" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReceivablesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_ReceivablesFairValueDisclosure_5fb6ee7f-5e2e-467e-aaf4-aa973be7d376" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_MaximumFundingPercentageOfResearchAndDevelopmentMilestones_5dd3dffd-2090-4731-9181-c5c1c50b1ba2" xlink:href="vtvt-20240331.xsd#vtvt_MaximumFundingPercentageOfResearchAndDevelopmentMilestones"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_vtvt_MaximumFundingPercentageOfResearchAndDevelopmentMilestones_5dd3dffd-2090-4731-9181-c5c1c50b1ba2" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_803d4268-3ee3-40fc-a5d6-e2d2a283f4c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice_803d4268-3ee3-40fc-a5d6-e2d2a283f4c2" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_d142073b-ffff-40d2-95fb-7627f9f07ac1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_4ab977c2-408b-4715-98c0-f6e31199fb1d" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_d142073b-ffff-40d2-95fb-7627f9f07ac1" xlink:type="arc" order="20"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/ShareBasedCompensationAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#ShareBasedCompensationAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/ShareBasedCompensationAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d70a2e7-5764-4e80-bcb4-067db8193792" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d70a2e7-5764-4e80-bcb4-067db8193792" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_14defde4-dddd-402b-9fc7-c48c055f6373" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d70a2e7-5764-4e80-bcb4-067db8193792" xlink:to="loc_us-gaap_AwardTypeAxis_14defde4-dddd-402b-9fc7-c48c055f6373" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_14defde4-dddd-402b-9fc7-c48c055f6373_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_14defde4-dddd-402b-9fc7-c48c055f6373" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_14defde4-dddd-402b-9fc7-c48c055f6373_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_65c3a5e5-ba57-4754-80e1-7d682d4ab2b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_14defde4-dddd-402b-9fc7-c48c055f6373" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_65c3a5e5-ba57-4754-80e1-7d682d4ab2b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_081f3642-0a4e-469b-9f9e-3b2d223dc9de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_65c3a5e5-ba57-4754-80e1-7d682d4ab2b9" xlink:to="loc_us-gaap_EmployeeStockOptionMember_081f3642-0a4e-469b-9f9e-3b2d223dc9de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_4cb9f81b-67ea-4390-b6c2-345e119e7d08" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_4cb9f81b-67ea-4390-b6c2-345e119e7d08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_d79502f5-97cb-44b7-8782-0780a8cc6481" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_d79502f5-97cb-44b7-8782-0780a8cc6481" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_e45b188c-713d-4072-b8f4-c3a597b51260" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_e45b188c-713d-4072-b8f4-c3a597b51260" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_7d0445c9-6de5-4481-86af-888fecb8f966" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_7d0445c9-6de5-4481-86af-888fecb8f966" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_5606ee40-748f-44d5-9e61-21559393189e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_5606ee40-748f-44d5-9e61-21559393189e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_796b3235-e9a0-4f28-a343-76470d8ed065" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_796b3235-e9a0-4f28-a343-76470d8ed065" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ShareBasedCompensationArrangementByShareBasedPaymentAwardModifiedCommonStock_3617943f-1f26-4491-aaf3-7fb086642663" xlink:href="vtvt-20240331.xsd#vtvt_ShareBasedCompensationArrangementByShareBasedPaymentAwardModifiedCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_vtvt_ShareBasedCompensationArrangementByShareBasedPaymentAwardModifiedCommonStock_3617943f-1f26-4491-aaf3-7fb086642663" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber_2d70d58e-e381-488f-8118-8890807f8cd9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber_2d70d58e-e381-488f-8118-8890807f8cd9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ShareBasedPaymentArrangementExpenseReductionAmount_7f4a09ec-1de8-40eb-9a55-c83ba3f0c3a8" xlink:href="vtvt-20240331.xsd#vtvt_ShareBasedPaymentArrangementExpenseReductionAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f0e389af-6b6b-455d-8549-4e343c9b43b2" xlink:to="loc_vtvt_ShareBasedPaymentArrangementExpenseReductionAmount_7f4a09ec-1de8-40eb-9a55-c83ba3f0c3a8" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/ShareBasedCompensationSummaryofCompensationExpenseRelatedtoGrantsofStockOptionsDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#ShareBasedCompensationSummaryofCompensationExpenseRelatedtoGrantsofStockOptionsDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/ShareBasedCompensationSummaryofCompensationExpenseRelatedtoGrantsofStockOptionsDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_e2d60fca-0ed6-4ea3-8162-0f676b2f091b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_68a1ded6-7b5d-4f5f-94cd-ecec0c6c646d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_e2d60fca-0ed6-4ea3-8162-0f676b2f091b" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_68a1ded6-7b5d-4f5f-94cd-ecec0c6c646d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_b0a1e3e6-a984-4ea0-8f85-f9bd3f7c673d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_68a1ded6-7b5d-4f5f-94cd-ecec0c6c646d" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_b0a1e3e6-a984-4ea0-8f85-f9bd3f7c673d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_b0a1e3e6-a984-4ea0-8f85-f9bd3f7c673d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_b0a1e3e6-a984-4ea0-8f85-f9bd3f7c673d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_b0a1e3e6-a984-4ea0-8f85-f9bd3f7c673d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_085951bd-3869-4d5c-a71c-369add3c3e9b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_b0a1e3e6-a984-4ea0-8f85-f9bd3f7c673d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_085951bd-3869-4d5c-a71c-369add3c3e9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_f5f2b682-1230-4f01-a6fc-44d8fc11c324" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_085951bd-3869-4d5c-a71c-369add3c3e9b" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_f5f2b682-1230-4f01-a6fc-44d8fc11c324" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_7f6f0050-a8d5-43d8-ab10-e31d4ae3732f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_085951bd-3869-4d5c-a71c-369add3c3e9b" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_7f6f0050-a8d5-43d8-ab10-e31d4ae3732f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_d79a63c4-13f2-42ad-8902-176a583a38bf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_e2d60fca-0ed6-4ea3-8162-0f676b2f091b" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_d79a63c4-13f2-42ad-8902-176a583a38bf" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/CommitmentsandContingenciesAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#CommitmentsandContingenciesAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/CommitmentsandContingenciesAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommitmentsAndContingenciesLineItems_d3c9e666-200c-486d-b602-c6c53649ed1e" xlink:href="vtvt-20240331.xsd#vtvt_CommitmentsAndContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommitmentsAndContingenciesTable_f11c3ebe-e40b-4ebc-8a76-c18aa4e685fe" xlink:href="vtvt-20240331.xsd#vtvt_CommitmentsAndContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_vtvt_CommitmentsAndContingenciesLineItems_d3c9e666-200c-486d-b602-c6c53649ed1e" xlink:to="loc_vtvt_CommitmentsAndContingenciesTable_f11c3ebe-e40b-4ebc-8a76-c18aa4e685fe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsAxis_bf518bac-545b-46cc-8cca-ab2166e0a31b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_CommitmentsAndContingenciesTable_f11c3ebe-e40b-4ebc-8a76-c18aa4e685fe" xlink:to="loc_us-gaap_OtherCommitmentsAxis_bf518bac-545b-46cc-8cca-ab2166e0a31b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsDomain_bf518bac-545b-46cc-8cca-ab2166e0a31b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OtherCommitmentsAxis_bf518bac-545b-46cc-8cca-ab2166e0a31b" xlink:to="loc_us-gaap_OtherCommitmentsDomain_bf518bac-545b-46cc-8cca-ab2166e0a31b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsDomain_36f4d6c3-17ba-44c4-b187-b893b44f9aee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OtherCommitmentsAxis_bf518bac-545b-46cc-8cca-ab2166e0a31b" xlink:to="loc_us-gaap_OtherCommitmentsDomain_36f4d6c3-17ba-44c4-b187-b893b44f9aee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_DevelopmentalAndRegulatoryMilestonePaymentMember_e4767e22-29b7-4e57-a7d1-2843030e817a" xlink:href="vtvt-20240331.xsd#vtvt_DevelopmentalAndRegulatoryMilestonePaymentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_36f4d6c3-17ba-44c4-b187-b893b44f9aee" xlink:to="loc_vtvt_DevelopmentalAndRegulatoryMilestonePaymentMember_e4767e22-29b7-4e57-a7d1-2843030e817a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SalesBasedMilestonesPaymentMember_6c22bd65-a6a5-4752-9997-de9707aba523" xlink:href="vtvt-20240331.xsd#vtvt_SalesBasedMilestonesPaymentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_36f4d6c3-17ba-44c4-b187-b893b44f9aee" xlink:to="loc_vtvt_SalesBasedMilestonesPaymentMember_6c22bd65-a6a5-4752-9997-de9707aba523" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_0961c356-3da9-4e00-b0dc-b307115428cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_CommitmentsAndContingenciesTable_f11c3ebe-e40b-4ebc-8a76-c18aa4e685fe" xlink:to="loc_us-gaap_TypeOfArrangementAxis_0961c356-3da9-4e00-b0dc-b307115428cc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_0961c356-3da9-4e00-b0dc-b307115428cc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_0961c356-3da9-4e00-b0dc-b307115428cc" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_0961c356-3da9-4e00-b0dc-b307115428cc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d9240247-c540-4e8a-842d-ff37d159216d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_0961c356-3da9-4e00-b0dc-b307115428cc" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d9240247-c540-4e8a-842d-ff37d159216d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_NovoLicenseAgreementMember_b119affd-3ea8-4f63-ab00-c3cf23572f6f" xlink:href="vtvt-20240331.xsd#vtvt_NovoLicenseAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_d9240247-c540-4e8a-842d-ff37d159216d" xlink:to="loc_vtvt_NovoLicenseAgreementMember_b119affd-3ea8-4f63-ab00-c3cf23572f6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis_cb9b0842-37aa-4fdb-9fee-44cbfe4de957" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_CommitmentsAndContingenciesTable_f11c3ebe-e40b-4ebc-8a76-c18aa4e685fe" xlink:to="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis_cb9b0842-37aa-4fdb-9fee-44cbfe4de957" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_cb9b0842-37aa-4fdb-9fee-44cbfe4de957_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis_cb9b0842-37aa-4fdb-9fee-44cbfe4de957" xlink:to="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_cb9b0842-37aa-4fdb-9fee-44cbfe4de957_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_923ce697-5e59-4b06-8bb4-6037ecbdb62f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis_cb9b0842-37aa-4fdb-9fee-44cbfe4de957" xlink:to="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_923ce697-5e59-4b06-8bb4-6037ecbdb62f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_OtherIndicationMember_9e5d82d0-fe0f-40b3-8e5b-8c3ddc0c0eb6" xlink:href="vtvt-20240331.xsd#vtvt_OtherIndicationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_923ce697-5e59-4b06-8bb4-6037ecbdb62f" xlink:to="loc_vtvt_OtherIndicationMember_9e5d82d0-fe0f-40b3-8e5b-8c3ddc0c0eb6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_TypeOneDiabetesMember_7b2bb460-ab8d-42ac-8db2-3134054c2938" xlink:href="vtvt-20240331.xsd#vtvt_TypeOneDiabetesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_923ce697-5e59-4b06-8bb4-6037ecbdb62f" xlink:to="loc_vtvt_TypeOneDiabetesMember_7b2bb460-ab8d-42ac-8db2-3134054c2938" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_TypeTwoDiabetesMember_38323af2-28ef-4491-919a-6391af6564c4" xlink:href="vtvt-20240331.xsd#vtvt_TypeTwoDiabetesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_923ce697-5e59-4b06-8bb4-6037ecbdb62f" xlink:to="loc_vtvt_TypeTwoDiabetesMember_38323af2-28ef-4491-919a-6391af6564c4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_c6641678-13f3-4254-9261-9fddda869c54" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_CommitmentsAndContingenciesTable_f11c3ebe-e40b-4ebc-8a76-c18aa4e685fe" xlink:to="loc_srt_RangeAxis_c6641678-13f3-4254-9261-9fddda869c54" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c6641678-13f3-4254-9261-9fddda869c54_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_c6641678-13f3-4254-9261-9fddda869c54" xlink:to="loc_srt_RangeMember_c6641678-13f3-4254-9261-9fddda869c54_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f2a2b35a-b5fb-4643-96df-5ae526f7ff34" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_c6641678-13f3-4254-9261-9fddda869c54" xlink:to="loc_srt_RangeMember_f2a2b35a-b5fb-4643-96df-5ae526f7ff34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_942a5a51-4b78-444c-9245-203dfa53f349" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f2a2b35a-b5fb-4643-96df-5ae526f7ff34" xlink:to="loc_srt_MaximumMember_942a5a51-4b78-444c-9245-203dfa53f349" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PotentialMilestonePayment_7e0119d2-a036-48ed-adc1-75ef7a896439" xlink:href="vtvt-20240331.xsd#vtvt_PotentialMilestonePayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_CommitmentsAndContingenciesLineItems_d3c9e666-200c-486d-b602-c6c53649ed1e" xlink:to="loc_vtvt_PotentialMilestonePayment_7e0119d2-a036-48ed-adc1-75ef7a896439" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/NoncontrollingInterestAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#NoncontrollingInterestAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/NoncontrollingInterestAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestTable_d616e3f6-7741-4f09-a19a-b71571d3d4b4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:to="loc_us-gaap_MinorityInterestTable_d616e3f6-7741-4f09-a19a-b71571d3d4b4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_23dbe45b-728c-43ea-9bd0-b5946d44c437" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_d616e3f6-7741-4f09-a19a-b71571d3d4b4" xlink:to="loc_dei_LegalEntityAxis_23dbe45b-728c-43ea-9bd0-b5946d44c437" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_23dbe45b-728c-43ea-9bd0-b5946d44c437_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_23dbe45b-728c-43ea-9bd0-b5946d44c437" xlink:to="loc_dei_EntityDomain_23dbe45b-728c-43ea-9bd0-b5946d44c437_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_df11a545-15db-4981-a4ee-b8f27e1eb792" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_23dbe45b-728c-43ea-9bd0-b5946d44c437" xlink:to="loc_dei_EntityDomain_df11a545-15db-4981-a4ee-b8f27e1eb792" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_VTvLLCMember_e191bcbf-4bac-4271-b7e6-e12005def8b5" xlink:href="vtvt-20240331.xsd#vtvt_VTvLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_df11a545-15db-4981-a4ee-b8f27e1eb792" xlink:to="loc_vtvt_VTvLLCMember_e191bcbf-4bac-4271-b7e6-e12005def8b5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_912cfcb2-5774-4b64-afea-a8f569976cb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_d616e3f6-7741-4f09-a19a-b71571d3d4b4" xlink:to="loc_us-gaap_StatementClassOfStockAxis_912cfcb2-5774-4b64-afea-a8f569976cb9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_912cfcb2-5774-4b64-afea-a8f569976cb9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_912cfcb2-5774-4b64-afea-a8f569976cb9" xlink:to="loc_us-gaap_ClassOfStockDomain_912cfcb2-5774-4b64-afea-a8f569976cb9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d18fa5b9-c7a5-4681-aae6-8ae36f5b3b94" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_912cfcb2-5774-4b64-afea-a8f569976cb9" xlink:to="loc_us-gaap_ClassOfStockDomain_d18fa5b9-c7a5-4681-aae6-8ae36f5b3b94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_02fae757-25d6-462f-aa17-9784d4d15702" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_d18fa5b9-c7a5-4681-aae6-8ae36f5b3b94" xlink:to="loc_us-gaap_CommonClassAMember_02fae757-25d6-462f-aa17-9784d4d15702" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_972614d8-c4c7-4326-b099-cea60f99963d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockByUniqueDescriptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_d616e3f6-7741-4f09-a19a-b71571d3d4b4" xlink:to="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_972614d8-c4c7-4326-b099-cea60f99963d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockNameDomain_972614d8-c4c7-4326-b099-cea60f99963d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_972614d8-c4c7-4326-b099-cea60f99963d" xlink:to="loc_us-gaap_ConversionOfStockNameDomain_972614d8-c4c7-4326-b099-cea60f99963d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockNameDomain_52a78b20-7128-4888-bd2d-332e7d9f8e22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConversionOfStockNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_972614d8-c4c7-4326-b099-cea60f99963d" xlink:to="loc_us-gaap_ConversionOfStockNameDomain_52a78b20-7128-4888-bd2d-332e7d9f8e22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ExchangeOfRedeemableNonControllingInterestToClassACommonStockMember_5fb56172-57fe-4f16-993f-f13360fa97fe" xlink:href="vtvt-20240331.xsd#vtvt_ExchangeOfRedeemableNonControllingInterestToClassACommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_52a78b20-7128-4888-bd2d-332e7d9f8e22" xlink:to="loc_vtvt_ExchangeOfRedeemableNonControllingInterestToClassACommonStockMember_5fb56172-57fe-4f16-993f-f13360fa97fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PercentageOfNonVotingEconomicInterest_03d016cf-7d13-4dba-a13c-a3957d4a840d" xlink:href="vtvt-20240331.xsd#vtvt_PercentageOfNonVotingEconomicInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:to="loc_vtvt_PercentageOfNonVotingEconomicInterest_03d016cf-7d13-4dba-a13c-a3957d4a840d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_RedeemableNonControllingInterestExchangeAgreementStockConversionRatio_858e2a0a-7536-4cf2-a0de-969ef113b29a" xlink:href="vtvt-20240331.xsd#vtvt_RedeemableNonControllingInterestExchangeAgreementStockConversionRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:to="loc_vtvt_RedeemableNonControllingInterestExchangeAgreementStockConversionRatio_858e2a0a-7536-4cf2-a0de-969ef113b29a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PeriodUsedToDetermineExchangeValueBasedOnWeightedAveragePriceOfClassCommonStock_7bc829b0-8ffc-4a15-8b00-e3e823391c68" xlink:href="vtvt-20240331.xsd#vtvt_PeriodUsedToDetermineExchangeValueBasedOnWeightedAveragePriceOfClassCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:to="loc_vtvt_PeriodUsedToDetermineExchangeValueBasedOnWeightedAveragePriceOfClassCommonStock_7bc829b0-8ffc-4a15-8b00-e3e823391c68" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityFairValue_4d4e458b-5141-4512-a00a-0890c53a9ade" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityFairValue_4d4e458b-5141-4512-a00a-0890c53a9ade" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_1d882f98-6473-48ed-9bea-9bfaf05a6757" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_de3b5cff-3580-434d-a5b3-f4aec0f570e0" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_1d882f98-6473-48ed-9bea-9bfaf05a6757" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/StockholdersEquityDeficitAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#StockholdersEquityDeficitAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/StockholdersEquityDeficitAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_3440a7dd-6aca-4193-96c3-a34902785fc4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:to="loc_us-gaap_StatementClassOfStockAxis_3440a7dd-6aca-4193-96c3-a34902785fc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3440a7dd-6aca-4193-96c3-a34902785fc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3440a7dd-6aca-4193-96c3-a34902785fc4" xlink:to="loc_us-gaap_ClassOfStockDomain_3440a7dd-6aca-4193-96c3-a34902785fc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_950cbec5-6717-4d16-b207-ff7b88e6443c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3440a7dd-6aca-4193-96c3-a34902785fc4" xlink:to="loc_us-gaap_ClassOfStockDomain_950cbec5-6717-4d16-b207-ff7b88e6443c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_16f6ccb8-33d8-43fc-a370-545d6045aca0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_950cbec5-6717-4d16-b207-ff7b88e6443c" xlink:to="loc_us-gaap_CommonClassAMember_16f6ccb8-33d8-43fc-a370-545d6045aca0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_37e6e187-1352-4e68-bdd5-a74b970f88fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_950cbec5-6717-4d16-b207-ff7b88e6443c" xlink:to="loc_us-gaap_CommonStockMember_37e6e187-1352-4e68-bdd5-a74b970f88fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_b856186c-c00b-46ec-8615-c7d9279a8df1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_950cbec5-6717-4d16-b207-ff7b88e6443c" xlink:to="loc_us-gaap_CommonClassBMember_b856186c-c00b-46ec-8615-c7d9279a8df1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6e2abaec-2036-4877-aa53-97e931031c8a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:to="loc_srt_RangeAxis_6e2abaec-2036-4877-aa53-97e931031c8a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6e2abaec-2036-4877-aa53-97e931031c8a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6e2abaec-2036-4877-aa53-97e931031c8a" xlink:to="loc_srt_RangeMember_6e2abaec-2036-4877-aa53-97e931031c8a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c9f490f1-0873-4b76-a908-fd2ed655f2fb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6e2abaec-2036-4877-aa53-97e931031c8a" xlink:to="loc_srt_RangeMember_c9f490f1-0873-4b76-a908-fd2ed655f2fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_49a3d647-0170-4511-936b-66622e7a9106" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_c9f490f1-0873-4b76-a908-fd2ed655f2fb" xlink:to="loc_srt_MaximumMember_49a3d647-0170-4511-936b-66622e7a9106" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_ea7f1ebc-aa1d-46f5-9548-bc4a930deb16" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:to="loc_srt_CounterpartyNameAxis_ea7f1ebc-aa1d-46f5-9548-bc4a930deb16" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ea7f1ebc-aa1d-46f5-9548-bc4a930deb16_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_ea7f1ebc-aa1d-46f5-9548-bc4a930deb16" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ea7f1ebc-aa1d-46f5-9548-bc4a930deb16_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7b0dddfe-6098-4d2e-afd0-242c23baab7d" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_ea7f1ebc-aa1d-46f5-9548-bc4a930deb16" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7b0dddfe-6098-4d2e-afd0-242c23baab7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_G42InvestmentsMember_9144ecb3-72a1-467b-ab0e-40d63d845aaf" xlink:href="vtvt-20240331.xsd#vtvt_G42InvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7b0dddfe-6098-4d2e-afd0-242c23baab7d" xlink:to="loc_vtvt_G42InvestmentsMember_9144ecb3-72a1-467b-ab0e-40d63d845aaf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CinRxInvestmentMember_52d59e7c-622b-4374-aad8-dd3d13e3bcdd" xlink:href="vtvt-20240331.xsd#vtvt_CinRxInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7b0dddfe-6098-4d2e-afd0-242c23baab7d" xlink:to="loc_vtvt_CinRxInvestmentMember_52d59e7c-622b-4374-aad8-dd3d13e3bcdd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_af861ec3-c19e-43a6-8c49-8f7c0f60a06c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_af861ec3-c19e-43a6-8c49-8f7c0f60a06c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_af861ec3-c19e-43a6-8c49-8f7c0f60a06c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_af861ec3-c19e-43a6-8c49-8f7c0f60a06c" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_af861ec3-c19e-43a6-8c49-8f7c0f60a06c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_412cfc68-82aa-4f76-a045-383dbdc76320" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_af861ec3-c19e-43a6-8c49-8f7c0f60a06c" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_412cfc68-82aa-4f76-a045-383dbdc76320" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivatePlacementMember_db31df54-cf4a-4731-9ae5-920e072e83cf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrivatePlacementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_412cfc68-82aa-4f76-a045-383dbdc76320" xlink:to="loc_us-gaap_PrivatePlacementMember_db31df54-cf4a-4731-9ae5-920e072e83cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_TDCowenSalesAgreementMember_ca70ac08-c112-4748-be3a-d7618f60cc78" xlink:href="vtvt-20240331.xsd#vtvt_TDCowenSalesAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_412cfc68-82aa-4f76-a045-383dbdc76320" xlink:to="loc_vtvt_TDCowenSalesAgreementMember_ca70ac08-c112-4748-be3a-d7618f60cc78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_f142916c-d9aa-4abf-bd87-1f3aacbef588" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_61a19ceb-3d5d-478c-81fe-5830fc07a609" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_f142916c-d9aa-4abf-bd87-1f3aacbef588" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_f142916c-d9aa-4abf-bd87-1f3aacbef588_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_f142916c-d9aa-4abf-bd87-1f3aacbef588" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_f142916c-d9aa-4abf-bd87-1f3aacbef588_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_626486b8-0884-4536-93e9-93b5c90ca72e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_f142916c-d9aa-4abf-bd87-1f3aacbef588" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_626486b8-0884-4536-93e9-93b5c90ca72e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PrivatePlacementPreFundedWarrantsMember_71d05d5c-97a4-44c4-b4e3-16bad344e43d" xlink:href="vtvt-20240331.xsd#vtvt_PrivatePlacementPreFundedWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_626486b8-0884-4536-93e9-93b5c90ca72e" xlink:to="loc_vtvt_PrivatePlacementPreFundedWarrantsMember_71d05d5c-97a4-44c4-b4e3-16bad344e43d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_79c1e528-9294-447c-976a-c51ef4174147" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_79c1e528-9294-447c-976a-c51ef4174147" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_IncreaseInCommonStockSharesAuthorized_144edaa1-0f5c-4830-8290-bc1105df5a02" xlink:href="vtvt-20240331.xsd#vtvt_IncreaseInCommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_IncreaseInCommonStockSharesAuthorized_144edaa1-0f5c-4830-8290-bc1105df5a02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommonStockAndPreferredStockSharesAuthorized_c1a0ade1-b6e9-4032-ba90-37a1eef26a6c" xlink:href="vtvt-20240331.xsd#vtvt_CommonStockAndPreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_CommonStockAndPreferredStockSharesAuthorized_c1a0ade1-b6e9-4032-ba90-37a1eef26a6c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_a84a640e-8af7-49b0-93ce-5e928bac74c2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_a84a640e-8af7-49b0-93ce-5e928bac74c2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_f842923d-93ec-47da-8c97-41496c79d65b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_f842923d-93ec-47da-8c97-41496c79d65b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_3da63907-d6f2-4ca3-be55-f37878558a0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_3da63907-d6f2-4ca3-be55-f37878558a0d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_823c44b5-9300-4f8a-a371-665f1c9b386e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_823c44b5-9300-4f8a-a371-665f1c9b386e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_e858fefc-f7bd-4d29-bbf1-45a1307dd48b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_e858fefc-f7bd-4d29-bbf1-45a1307dd48b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_ee456620-6882-4217-9225-18ff11a6fe38" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_ee456620-6882-4217-9225-18ff11a6fe38" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_02240e66-0db6-425e-89c0-03f016f75e33" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_02240e66-0db6-425e-89c0-03f016f75e33" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ClassOfWarrantOrRightPercentOfSecuritiesCalledByWarrantsOrRights_310a3f17-442e-4c0c-851a-b9719bd16564" xlink:href="vtvt-20240331.xsd#vtvt_ClassOfWarrantOrRightPercentOfSecuritiesCalledByWarrantsOrRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_ClassOfWarrantOrRightPercentOfSecuritiesCalledByWarrantsOrRights_310a3f17-442e-4c0c-851a-b9719bd16564" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementShares_e869773f-cc0e-4979-8c47-439400fe4e42" xlink:href="vtvt-20240331.xsd#vtvt_CommonStockParOrStatedValueOfPrivatePlacementShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementShares_e869773f-cc0e-4979-8c47-439400fe4e42" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementPreFundedWarrantsShares_defa4655-cbfc-4b55-ad01-a4dee5e45e91" xlink:href="vtvt-20240331.xsd#vtvt_CommonStockParOrStatedValueOfPrivatePlacementPreFundedWarrantsShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_CommonStockParOrStatedValueOfPrivatePlacementPreFundedWarrantsShares_defa4655-cbfc-4b55-ad01-a4dee5e45e91" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockConsiderationReceivedOnTransactionGross_e0f44aeb-d46a-4b6c-a3d3-9cf45338663e" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockConsiderationReceivedOnTransactionGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_SaleOfStockConsiderationReceivedOnTransactionGross_e0f44aeb-d46a-4b6c-a3d3-9cf45338663e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_bef83885-dcef-4f2e-bd82-8bfd10c2656e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_bef83885-dcef-4f2e-bd82-8bfd10c2656e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_ddb8d4ee-502c-4341-987a-43e86945ca8f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsNotesAndLoansReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_ddb8d4ee-502c-4341-987a-43e86945ca8f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockConsiderationReceivableTerm_cab852ae-06db-483b-9450-9f278ed814ee" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockConsiderationReceivableTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_SaleOfStockConsiderationReceivableTerm_cab852ae-06db-483b-9450-9f278ed814ee" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromCollectionOfNotesReceivable_1d834db2-59c3-40f7-b857-c8eee2abbf50" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromCollectionOfNotesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_ProceedsFromCollectionOfNotesReceivable_1d834db2-59c3-40f7-b857-c8eee2abbf50" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_NotesReceivableDiscountRate_71508637-c24e-4bb4-a710-fa20ef8ceac3" xlink:href="vtvt-20240331.xsd#vtvt_NotesReceivableDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_NotesReceivableDiscountRate_71508637-c24e-4bb4-a710-fa20ef8ceac3" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_df762ef9-87ea-483e-adb3-162b62084ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_df762ef9-87ea-483e-adb3-162b62084ce7" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_651329c6-2f81-44be-be61-f7c3420a7b30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_651329c6-2f81-44be-be61-f7c3420a7b30" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_ea0486e8-4476-4f49-88da-9e84da830a9a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_ea0486e8-4476-4f49-88da-9e84da830a9a" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockAggregateOfferingPrice_2be77c76-62fc-486d-b73f-bbadf37f1d17" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockAggregateOfferingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_SaleOfStockAggregateOfferingPrice_2be77c76-62fc-486d-b73f-bbadf37f1d17" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_EntityPublicFloatThreshold_14d73f45-93e7-41aa-bf88-e487b765296b" xlink:href="vtvt-20240331.xsd#vtvt_EntityPublicFloatThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_EntityPublicFloatThreshold_14d73f45-93e7-41aa-bf88-e487b765296b" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockMaximumSecuritiesToBeSoldPercentOfPublicFloat_31b86ebf-65a4-4aab-bd19-85f683ea4765" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockMaximumSecuritiesToBeSoldPercentOfPublicFloat"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_vtvt_SaleOfStockMaximumSecuritiesToBeSoldPercentOfPublicFloat_31b86ebf-65a4-4aab-bd19-85f683ea4765" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_5d3ba71f-b069-42a8-8aee-5d0d988d05de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0b1d5e10-1d6d-4ea8-871c-a752f4ef25c2" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_5d3ba71f-b069-42a8-8aee-5d0d988d05de" xlink:type="arc" order="25"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/RelatedPartyTransactionsAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#RelatedPartyTransactionsAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/RelatedPartyTransactionsAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_bf77305b-7722-4d03-a43b-203b72b07afb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_bf77305b-7722-4d03-a43b-203b72b07afb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_80d6b3ff-7eb8-4d90-867a-a32f2acb1884" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_bf77305b-7722-4d03-a43b-203b72b07afb" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_80d6b3ff-7eb8-4d90-867a-a32f2acb1884" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_80d6b3ff-7eb8-4d90-867a-a32f2acb1884_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_80d6b3ff-7eb8-4d90-867a-a32f2acb1884" xlink:to="loc_us-gaap_RelatedPartyDomain_80d6b3ff-7eb8-4d90-867a-a32f2acb1884_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_8bcf7b89-70b7-422e-a15c-cab3a17d12d3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_80d6b3ff-7eb8-4d90-867a-a32f2acb1884" xlink:to="loc_us-gaap_RelatedPartyDomain_8bcf7b89-70b7-422e-a15c-cab3a17d12d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_cafac656-3c68-4376-87c7-5fff23205ed9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_8bcf7b89-70b7-422e-a15c-cab3a17d12d3" xlink:to="loc_us-gaap_RelatedPartyMember_cafac656-3c68-4376-87c7-5fff23205ed9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_d36d5202-e183-403c-bb81-8c489feb8ab3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_bf77305b-7722-4d03-a43b-203b72b07afb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_d36d5202-e183-403c-bb81-8c489feb8ab3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_d36d5202-e183-403c-bb81-8c489feb8ab3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d36d5202-e183-403c-bb81-8c489feb8ab3" xlink:to="loc_us-gaap_ClassOfStockDomain_d36d5202-e183-403c-bb81-8c489feb8ab3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_2d890aaf-ffc7-4113-90e6-1f3c5106d7ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_d36d5202-e183-403c-bb81-8c489feb8ab3" xlink:to="loc_us-gaap_ClassOfStockDomain_2d890aaf-ffc7-4113-90e6-1f3c5106d7ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_77a560bb-35aa-4ade-800c-f8d5d1bcf534" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2d890aaf-ffc7-4113-90e6-1f3c5106d7ee" xlink:to="loc_us-gaap_CommonClassBMember_77a560bb-35aa-4ade-800c-f8d5d1bcf534" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_2b88f54b-b28f-450a-a9b4-eede44ec78e5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_2d890aaf-ffc7-4113-90e6-1f3c5106d7ee" xlink:to="loc_us-gaap_CommonClassAMember_2b88f54b-b28f-450a-a9b4-eede44ec78e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_f1c755bf-e9c8-41eb-a649-fac7327deb3f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_bf77305b-7722-4d03-a43b-203b72b07afb" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_f1c755bf-e9c8-41eb-a649-fac7327deb3f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_f1c755bf-e9c8-41eb-a649-fac7327deb3f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_f1c755bf-e9c8-41eb-a649-fac7327deb3f" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_f1c755bf-e9c8-41eb-a649-fac7327deb3f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_cb2869df-ee7f-4be7-86b6-a99eadf23d1e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_f1c755bf-e9c8-41eb-a649-fac7327deb3f" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_cb2869df-ee7f-4be7-86b6-a99eadf23d1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_MacAndrewsAndForbesIncorporatedMember_2bba9de8-f691-47ed-84da-15066ac63831" xlink:href="vtvt-20240331.xsd#vtvt_MacAndrewsAndForbesIncorporatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_cb2869df-ee7f-4be7-86b6-a99eadf23d1e" xlink:to="loc_vtvt_MacAndrewsAndForbesIncorporatedMember_2bba9de8-f691-47ed-84da-15066ac63831" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_G42InvestmentsMember_712e85ac-f1a9-4d3a-8455-9913582fc22c" xlink:href="vtvt-20240331.xsd#vtvt_G42InvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_cb2869df-ee7f-4be7-86b6-a99eadf23d1e" xlink:to="loc_vtvt_G42InvestmentsMember_712e85ac-f1a9-4d3a-8455-9913582fc22c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalanceShares_252de0f3-f1f1-4bdf-b6d7-da9b90930d9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentOwnedBalanceShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_InvestmentOwnedBalanceShares_252de0f3-f1f1-4bdf-b6d7-da9b90930d9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_OwnershipPercentageOfMajorityOwner_e72058ac-792f-4d1d-9939-7b73740be216" xlink:href="vtvt-20240331.xsd#vtvt_OwnershipPercentageOfMajorityOwner"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_vtvt_OwnershipPercentageOfMajorityOwner_e72058ac-792f-4d1d-9939-7b73740be216" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PercentageOfAmountOfCashSavings_ae57609c-5245-4527-8ef1-09e37532434b" xlink:href="vtvt-20240331.xsd#vtvt_PercentageOfAmountOfCashSavings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_vtvt_PercentageOfAmountOfCashSavings_ae57609c-5245-4527-8ef1-09e37532434b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_2457d23c-d804-4908-9614-85eeaef33a61" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_2457d23c-d804-4908-9614-85eeaef33a61" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_b62c0b1e-fd51-4bad-91a6-28f6fbb37e76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_b62c0b1e-fd51-4bad-91a6-28f6fbb37e76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_SaleOfStockConsiderationReceivedOnTransactionGross_99917aaa-46bf-42f3-b438-963320619e33" xlink:href="vtvt-20240331.xsd#vtvt_SaleOfStockConsiderationReceivedOnTransactionGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_vtvt_SaleOfStockConsiderationReceivedOnTransactionGross_99917aaa-46bf-42f3-b438-963320619e33" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_e5885e57-5eda-41e4-9db2-04cb593b3a28" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_e5885e57-5eda-41e4-9db2-04cb593b3a28" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_b0c246c8-5cbc-4635-a25f-1ac37166e341" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsNotesAndLoansReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_AccountsNotesAndLoansReceivableNetCurrent_b0c246c8-5cbc-4635-a25f-1ac37166e341" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromCollectionOfNotesReceivable_8113ae96-0483-4ebc-96c2-208b64f2bdba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromCollectionOfNotesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_ProceedsFromCollectionOfNotesReceivable_8113ae96-0483-4ebc-96c2-208b64f2bdba" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_NotesReceivableDiscountRate_3ef40e53-6603-4d48-9645-cf954209abb3" xlink:href="vtvt-20240331.xsd#vtvt_NotesReceivableDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_vtvt_NotesReceivableDiscountRate_3ef40e53-6603-4d48-9645-cf954209abb3" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_c829093b-9d43-4951-a433-95012b4efbc1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_2898a99b-48a6-4e8b-bdad-bc442fcef9b9" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_c829093b-9d43-4951-a433-95012b4efbc1" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/IncomeTaxesAdditionalInformationDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#IncomeTaxesAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/IncomeTaxesAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_IncomeTaxesLineItems_535de572-cd2d-4beb-9b76-73b3af93ff3d" xlink:href="vtvt-20240331.xsd#vtvt_IncomeTaxesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_IncomeTaxesTable_051d7e3b-7e03-441b-97e4-6624ca51e954" xlink:href="vtvt-20240331.xsd#vtvt_IncomeTaxesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_vtvt_IncomeTaxesLineItems_535de572-cd2d-4beb-9b76-73b3af93ff3d" xlink:to="loc_vtvt_IncomeTaxesTable_051d7e3b-7e03-441b-97e4-6624ca51e954" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_0e040674-3631-4a98-bab7-218152519ddc" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_IncomeTaxesTable_051d7e3b-7e03-441b-97e4-6624ca51e954" xlink:to="loc_dei_LegalEntityAxis_0e040674-3631-4a98-bab7-218152519ddc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_0e040674-3631-4a98-bab7-218152519ddc_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_0e040674-3631-4a98-bab7-218152519ddc" xlink:to="loc_dei_EntityDomain_0e040674-3631-4a98-bab7-218152519ddc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_93300afe-d177-452d-9944-9f40f3a14ce4" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_0e040674-3631-4a98-bab7-218152519ddc" xlink:to="loc_dei_EntityDomain_93300afe-d177-452d-9944-9f40f3a14ce4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_MFTTPHoldingsLLCMember_2cd2d79f-bccb-455f-bef5-9ff77f525f63" xlink:href="vtvt-20240331.xsd#vtvt_MFTTPHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_93300afe-d177-452d-9944-9f40f3a14ce4" xlink:to="loc_vtvt_MFTTPHoldingsLLCMember_2cd2d79f-bccb-455f-bef5-9ff77f525f63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_50cf2db5-e1da-44f2-ad49-ce1748ecb634" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_IncomeTaxesLineItems_535de572-cd2d-4beb-9b76-73b3af93ff3d" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_50cf2db5-e1da-44f2-ad49-ce1748ecb634" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_PercentageOfAmountOfCashSavings_41d31276-4d21-4cc3-94c0-733457f05b80" xlink:href="vtvt-20240331.xsd#vtvt_PercentageOfAmountOfCashSavings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_IncomeTaxesLineItems_535de572-cd2d-4beb-9b76-73b3af93ff3d" xlink:to="loc_vtvt_PercentageOfAmountOfCashSavings_41d31276-4d21-4cc3-94c0-733457f05b80" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/NetLossperShareReconciliationoftheNumeratorandDenominatorUsedintheCalculationofBasicandDilutedNetLossperShareofClassACommonStockDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#NetLossperShareReconciliationoftheNumeratorandDenominatorUsedintheCalculationofBasicandDilutedNetLossperShareofClassACommonStockDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/NetLossperShareReconciliationoftheNumeratorandDenominatorUsedintheCalculationofBasicandDilutedNetLossperShareofClassACommonStockDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ScheduleOfEarningsPerShareLineItems_4623f73d-926a-4cdf-b5e4-d4d4794cae8c" xlink:href="vtvt-20240331.xsd#vtvt_ScheduleOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_ScheduleOfEarningsPerShareTable_cecc2873-66bb-4429-be19-c2b196ca9f8c" xlink:href="vtvt-20240331.xsd#vtvt_ScheduleOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_vtvt_ScheduleOfEarningsPerShareLineItems_4623f73d-926a-4cdf-b5e4-d4d4794cae8c" xlink:to="loc_vtvt_ScheduleOfEarningsPerShareTable_cecc2873-66bb-4429-be19-c2b196ca9f8c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_8783c31f-16fa-4bef-9160-2be2afe08053" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_ScheduleOfEarningsPerShareTable_cecc2873-66bb-4429-be19-c2b196ca9f8c" xlink:to="loc_us-gaap_StatementClassOfStockAxis_8783c31f-16fa-4bef-9160-2be2afe08053" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_8783c31f-16fa-4bef-9160-2be2afe08053_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_8783c31f-16fa-4bef-9160-2be2afe08053" xlink:to="loc_us-gaap_ClassOfStockDomain_8783c31f-16fa-4bef-9160-2be2afe08053_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_18d55951-381f-4ac7-a051-8c87dcdf6269" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_8783c31f-16fa-4bef-9160-2be2afe08053" xlink:to="loc_us-gaap_ClassOfStockDomain_18d55951-381f-4ac7-a051-8c87dcdf6269" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_bc4ffb11-4a93-409f-bdeb-6148c6761665" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_18d55951-381f-4ac7-a051-8c87dcdf6269" xlink:to="loc_us-gaap_CommonClassAMember_bc4ffb11-4a93-409f-bdeb-6148c6761665" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAbstract_4e393a13-4a1a-4fa7-9dec-21259a3b3701" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_ScheduleOfEarningsPerShareLineItems_4623f73d-926a-4cdf-b5e4-d4d4794cae8c" xlink:to="loc_us-gaap_NetIncomeLossAbstract_4e393a13-4a1a-4fa7-9dec-21259a3b3701" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_fdcdd1f6-f2c8-4e55-8cbc-3e481019c000" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_4e393a13-4a1a-4fa7-9dec-21259a3b3701" xlink:to="loc_us-gaap_ProfitLoss_fdcdd1f6-f2c8-4e55-8cbc-3e481019c000" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_ea489355-0179-4840-ae69-6b3b95d9797b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_4e393a13-4a1a-4fa7-9dec-21259a3b3701" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_ea489355-0179-4840-ae69-6b3b95d9797b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_00fd040c-dd73-48cc-be01-fb2b0053315a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_4e393a13-4a1a-4fa7-9dec-21259a3b3701" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_00fd040c-dd73-48cc-be01-fb2b0053315a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_26487d2a-1e90-4739-a762-9f71a5505f1b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_4e393a13-4a1a-4fa7-9dec-21259a3b3701" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_26487d2a-1e90-4739-a762-9f71a5505f1b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3e9157bc-c23f-4759-a99a-c2aad952ee47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_ScheduleOfEarningsPerShareLineItems_4623f73d-926a-4cdf-b5e4-d4d4794cae8c" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3e9157bc-c23f-4759-a99a-c2aad952ee47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_531fb99d-c614-4791-bbdf-2ef5e6e85d81" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3e9157bc-c23f-4759-a99a-c2aad952ee47" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_531fb99d-c614-4791-bbdf-2ef5e6e85d81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1d26bef2-7756-49c5-9dce-bb3e4a4229d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3e9157bc-c23f-4759-a99a-c2aad952ee47" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_1d26bef2-7756-49c5-9dce-bb3e4a4229d1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_4517df3c-38e9-4fdd-b14f-8baa7106ab9e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3e9157bc-c23f-4759-a99a-c2aad952ee47" xlink:to="loc_us-gaap_EarningsPerShareBasic_4517df3c-38e9-4fdd-b14f-8baa7106ab9e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_64b7c694-e30b-46e3-b55d-ca931434c370" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3e9157bc-c23f-4759-a99a-c2aad952ee47" xlink:to="loc_us-gaap_EarningsPerShareDiluted_64b7c694-e30b-46e3-b55d-ca931434c370" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/NetLossperShareScheduleofPotentiallyDilutiveSecuritiesnotIncludedinCalculationofDilutedNetLossperShareDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#NetLossperShareScheduleofPotentiallyDilutiveSecuritiesnotIncludedinCalculationofDilutedNetLossperShareDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/NetLossperShareScheduleofPotentiallyDilutiveSecuritiesnotIncludedinCalculationofDilutedNetLossperShareDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4ed04b47-5778-44e8-b45c-7b1afc3dfeeb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_0de9c7f1-849a-485e-a26a-8a3b409e749b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4ed04b47-5778-44e8-b45c-7b1afc3dfeeb" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_0de9c7f1-849a-485e-a26a-8a3b409e749b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_4b0afc81-9a8d-4b19-b83d-9d4554d7fdc6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_0de9c7f1-849a-485e-a26a-8a3b409e749b" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_4b0afc81-9a8d-4b19-b83d-9d4554d7fdc6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4b0afc81-9a8d-4b19-b83d-9d4554d7fdc6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_4b0afc81-9a8d-4b19-b83d-9d4554d7fdc6" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_4b0afc81-9a8d-4b19-b83d-9d4554d7fdc6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_f56c85c2-0a06-4b28-88a2-461ebb5ef0dd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_4b0afc81-9a8d-4b19-b83d-9d4554d7fdc6" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_f56c85c2-0a06-4b28-88a2-461ebb5ef0dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_f9445fe2-e494-4e78-a8c8-3d7e1c2e34af" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_f56c85c2-0a06-4b28-88a2-461ebb5ef0dd" xlink:to="loc_us-gaap_CommonClassBMember_f9445fe2-e494-4e78-a8c8-3d7e1c2e34af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_2f7555b9-5844-4a67-84c1-3f3b8a7098e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_f56c85c2-0a06-4b28-88a2-461ebb5ef0dd" xlink:to="loc_us-gaap_EmployeeStockOptionMember_2f7555b9-5844-4a67-84c1-3f3b8a7098e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_0bda1f01-3dbb-4294-afd4-fa37705a7abf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_f56c85c2-0a06-4b28-88a2-461ebb5ef0dd" xlink:to="loc_us-gaap_WarrantMember_0bda1f01-3dbb-4294-afd4-fa37705a7abf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_58d5439b-4405-4c61-8c94-acd50db953d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4ed04b47-5778-44e8-b45c-7b1afc3dfeeb" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_58d5439b-4405-4c61-8c94-acd50db953d1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/FairValueofFinancialInstrumentsSummarizestheConclusionsReachedRegardingFairValueMeasurementsDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#FairValueofFinancialInstrumentsSummarizestheConclusionsReachedRegardingFairValueMeasurementsDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/FairValueofFinancialInstrumentsSummarizestheConclusionsReachedRegardingFairValueMeasurementsDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisLineItems_a5504118-d541-41e1-b6a3-2654b02b57a4" xlink:href="vtvt-20240331.xsd#vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisTable_22b8da70-fe90-436e-b7fe-6ddeaa835ee1" xlink:href="vtvt-20240331.xsd#vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisLineItems_a5504118-d541-41e1-b6a3-2654b02b57a4" xlink:to="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisTable_22b8da70-fe90-436e-b7fe-6ddeaa835ee1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_3e894cd1-a008-45b5-bfeb-7fa4049b530a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisTable_22b8da70-fe90-436e-b7fe-6ddeaa835ee1" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_3e894cd1-a008-45b5-bfeb-7fa4049b530a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_3e894cd1-a008-45b5-bfeb-7fa4049b530a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_3e894cd1-a008-45b5-bfeb-7fa4049b530a" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_3e894cd1-a008-45b5-bfeb-7fa4049b530a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_f9cfac78-99a1-4f6a-80e5-cdbd1cf8ee6c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_3e894cd1-a008-45b5-bfeb-7fa4049b530a" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_f9cfac78-99a1-4f6a-80e5-cdbd1cf8ee6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_258b872e-efb1-49f1-a473-c7c0d389fd37" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_f9cfac78-99a1-4f6a-80e5-cdbd1cf8ee6c" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_258b872e-efb1-49f1-a473-c7c0d389fd37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6e441774-9a26-4f70-a2c6-d04257787636" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisTable_22b8da70-fe90-436e-b7fe-6ddeaa835ee1" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6e441774-9a26-4f70-a2c6-d04257787636" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6e441774-9a26-4f70-a2c6-d04257787636_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6e441774-9a26-4f70-a2c6-d04257787636" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6e441774-9a26-4f70-a2c6-d04257787636_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f7b500b-a1a6-4780-a32d-3cbd246a1aee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6e441774-9a26-4f70-a2c6-d04257787636" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f7b500b-a1a6-4780-a32d-3cbd246a1aee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_75688f8e-a2e7-49be-a3d4-d1d7d0453a3e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f7b500b-a1a6-4780-a32d-3cbd246a1aee" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_75688f8e-a2e7-49be-a3d4-d1d7d0453a3e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_49fe47b2-aca5-4997-ba86-876d99f3435a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f7b500b-a1a6-4780-a32d-3cbd246a1aee" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_49fe47b2-aca5-4997-ba86-876d99f3435a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_c00b4eb7-ed3f-4115-b7ea-8d6f276d36ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f7b500b-a1a6-4780-a32d-3cbd246a1aee" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_c00b4eb7-ed3f-4115-b7ea-8d6f276d36ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_c65e7a90-8ee0-41a5-88b0-c7728fdb927a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisTable_22b8da70-fe90-436e-b7fe-6ddeaa835ee1" xlink:to="loc_us-gaap_FinancialInstrumentAxis_c65e7a90-8ee0-41a5-88b0-c7728fdb927a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_c65e7a90-8ee0-41a5-88b0-c7728fdb927a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_c65e7a90-8ee0-41a5-88b0-c7728fdb927a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_c65e7a90-8ee0-41a5-88b0-c7728fdb927a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2eb9551a-8164-4113-b294-8bd581df5583" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_c65e7a90-8ee0-41a5-88b0-c7728fdb927a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2eb9551a-8164-4113-b294-8bd581df5583" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_WarrantLiabilityRelatedPartyMember_debecdda-c0fd-488a-96c8-8bd4f8df08c9" xlink:href="vtvt-20240331.xsd#vtvt_WarrantLiabilityRelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2eb9551a-8164-4113-b294-8bd581df5583" xlink:to="loc_vtvt_WarrantLiabilityRelatedPartyMember_debecdda-c0fd-488a-96c8-8bd4f8df08c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_58beea58-367b-4e82-abc3-bdb737fa782e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisLineItems_a5504118-d541-41e1-b6a3-2654b02b57a4" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_58beea58-367b-4e82-abc3-bdb737fa782e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_fb06b906-9acd-4976-876b-d5f7836424a4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_vtvt_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringBasisLineItems_a5504118-d541-41e1-b6a3-2654b02b57a4" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_fb06b906-9acd-4976-876b-d5f7836424a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_e3d48e9e-3dd9-42fa-b649-638e3bcb22a7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_fb06b906-9acd-4976-876b-d5f7836424a4" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_e3d48e9e-3dd9-42fa-b649-638e3bcb22a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings_0f13d8d7-a6d1-42e7-8b31-89d1a38c8ddb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_fb06b906-9acd-4976-876b-d5f7836424a4" xlink:to="loc_us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationGainLossIncludedInEarnings_0f13d8d7-a6d1-42e7-8b31-89d1a38c8ddb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases_59c11cd9-80cc-4a01-9861-c6dfb83bc280" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_fb06b906-9acd-4976-876b-d5f7836424a4" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchases_59c11cd9-80cc-4a01-9861-c6dfb83bc280" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySales_34904376-87b3-4166-b90f-b5238da7213c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_fb06b906-9acd-4976-876b-d5f7836424a4" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySales_34904376-87b3-4166-b90f-b5238da7213c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_3cfc96b3-3f15-46f0-bff0-6dabf106c046" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://vtvtherapeutics.com/role/FairValueofFinancialInstrumentsFairValueMeasurementInputsandValuationTechniquesDetail" xlink:type="simple" xlink:href="vtvt-20240331.xsd#FairValueofFinancialInstrumentsFairValueMeasurementInputsandValuationTechniquesDetail"/>
  <link:definitionLink xlink:role="http://vtvtherapeutics.com/role/FairValueofFinancialInstrumentsFairValueMeasurementInputsandValuationTechniquesDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27fab3a1-dda9-43d6-991d-997e54103476" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_daf975f3-85e7-45d6-bb12-ef6b7cbcffee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27fab3a1-dda9-43d6-991d-997e54103476" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_daf975f3-85e7-45d6-bb12-ef6b7cbcffee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_f74a84e0-ccb3-436d-be4f-8752580ba796" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_daf975f3-85e7-45d6-bb12-ef6b7cbcffee" xlink:to="loc_srt_RangeAxis_f74a84e0-ccb3-436d-be4f-8752580ba796" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f74a84e0-ccb3-436d-be4f-8752580ba796_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_f74a84e0-ccb3-436d-be4f-8752580ba796" xlink:to="loc_srt_RangeMember_f74a84e0-ccb3-436d-be4f-8752580ba796_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4420eb41-a254-4fa1-a980-662fc929afb0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_f74a84e0-ccb3-436d-be4f-8752580ba796" xlink:to="loc_srt_RangeMember_4420eb41-a254-4fa1-a980-662fc929afb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_a3959c08-54d1-4969-9d64-a075a5ab0a9a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4420eb41-a254-4fa1-a980-662fc929afb0" xlink:to="loc_srt_MinimumMember_a3959c08-54d1-4969-9d64-a075a5ab0a9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_1568357e-ab92-40f8-8997-1cdbf60a3e97" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4420eb41-a254-4fa1-a980-662fc929afb0" xlink:to="loc_srt_MaximumMember_1568357e-ab92-40f8-8997-1cdbf60a3e97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_40ff7408-1284-424a-b3ee-30dcbfdee111" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_4420eb41-a254-4fa1-a980-662fc929afb0" xlink:to="loc_srt_WeightedAverageMember_40ff7408-1284-424a-b3ee-30dcbfdee111" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_4148907f-4496-42a7-9151-c255714c730e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_daf975f3-85e7-45d6-bb12-ef6b7cbcffee" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_4148907f-4496-42a7-9151-c255714c730e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_4148907f-4496-42a7-9151-c255714c730e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_4148907f-4496-42a7-9151-c255714c730e" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_4148907f-4496-42a7-9151-c255714c730e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_300d0657-d7a0-4590-929d-716910df8f15" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_4148907f-4496-42a7-9151-c255714c730e" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_300d0657-d7a0-4590-929d-716910df8f15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPriceVolatilityMember_f65237f9-0a7e-481c-9503-c7ba1dbe3da8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_300d0657-d7a0-4590-929d-716910df8f15" xlink:to="loc_us-gaap_MeasurementInputPriceVolatilityMember_f65237f9-0a7e-481c-9503-c7ba1dbe3da8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_e492ed80-5920-4a3e-9a57-50fb9450f7bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_300d0657-d7a0-4590-929d-716910df8f15" xlink:to="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_e492ed80-5920-4a3e-9a57-50fb9450f7bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputExpectedDividendRateMember_f16a9f93-710b-48af-bb2d-42fdba8a64af" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MeasurementInputExpectedDividendRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_300d0657-d7a0-4590-929d-716910df8f15" xlink:to="loc_us-gaap_MeasurementInputExpectedDividendRateMember_f16a9f93-710b-48af-bb2d-42fdba8a64af" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_2894413d-38d4-480e-b2be-e48907358323" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_daf975f3-85e7-45d6-bb12-ef6b7cbcffee" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_2894413d-38d4-480e-b2be-e48907358323" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_2894413d-38d4-480e-b2be-e48907358323_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_2894413d-38d4-480e-b2be-e48907358323" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_2894413d-38d4-480e-b2be-e48907358323_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_e2ed051d-24dc-4c68-99cf-8b97189137bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_2894413d-38d4-480e-b2be-e48907358323" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_e2ed051d-24dc-4c68-99cf-8b97189137bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_LetterAgreementWarrantsMember_e1e15ec5-d8a8-448c-a744-28c802095a06" xlink:href="vtvt-20240331.xsd#vtvt_LetterAgreementWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_e2ed051d-24dc-4c68-99cf-8b97189137bb" xlink:to="loc_vtvt_LetterAgreementWarrantsMember_e1e15ec5-d8a8-448c-a744-28c802095a06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_vtvt_CinRxWarrantsMember_58249160-1855-4f5c-9194-544cc307643d" xlink:href="vtvt-20240331.xsd#vtvt_CinRxWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_e2ed051d-24dc-4c68-99cf-8b97189137bb" xlink:to="loc_vtvt_CinRxWarrantsMember_58249160-1855-4f5c-9194-544cc307643d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingMeasurementInput_ca2a1109-9a47-44a6-a7f1-a414e180dd6d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstandingMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27fab3a1-dda9-43d6-991d-997e54103476" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingMeasurementInput_ca2a1109-9a47-44a6-a7f1-a414e180dd6d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_07ec5bd7-5922-4fbf-9098-24937ccb0220" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27fab3a1-dda9-43d6-991d-997e54103476" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_07ec5bd7-5922-4fbf-9098-24937ccb0220" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
