<?xml version="1.0" encoding="US-ASCII"?>
<!-- Generated by Broadridge Transform (tm) - http://www.broadridge.com -->
<!-- Created: Thu Sep 17 14:26:59 UTC 2026 -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xbrldt="http://xbrl.org/2005/xbrldt">
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ConsolidatedBalanceSheet" roleURI="http://www.vogenx.com/role/ConsolidatedBalanceSheet"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ConsolidatedBalanceSheet_Parentheticals" roleURI="http://www.vogenx.com/role/ConsolidatedBalanceSheet_Parentheticals"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ConsolidatedIncomeStatement" roleURI="http://www.vogenx.com/role/ConsolidatedIncomeStatement"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ShareholdersEquityType2or3" roleURI="http://www.vogenx.com/role/ShareholdersEquityType2or3"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ConsolidatedCashFlow" roleURI="http://www.vogenx.com/role/ConsolidatedCashFlow"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_OrganizationandNatureofBusiness" roleURI="http://www.vogenx.com/role/OrganizationandNatureofBusiness"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_SummaryofSignificantAccountingPolicies" roleURI="http://www.vogenx.com/role/SummaryofSignificantAccountingPolicies"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_AccruedExpenses" roleURI="http://www.vogenx.com/role/AccruedExpenses"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ConvertiblePromissoryNotesPayableRelatedParty" roleURI="http://www.vogenx.com/role/ConvertiblePromissoryNotesPayableRelatedParty"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_Warrants" roleURI="http://www.vogenx.com/role/Warrants"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_StockholdersDeficit" roleURI="http://www.vogenx.com/role/StockholdersDeficit"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_NetLossPerCommonShare" roleURI="http://www.vogenx.com/role/NetLossPerCommonShare"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_AccountingPoliciesByPolicy" roleURI="http://www.vogenx.com/role/AccountingPoliciesByPolicy"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_SummaryofSignificantAccountingPoliciesTables" roleURI="http://www.vogenx.com/role/SummaryofSignificantAccountingPoliciesTables"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_NetLossPerCommonShareTables" roleURI="http://www.vogenx.com/role/NetLossPerCommonShareTables"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ScheduleofSegmentLossandSignificantExpenseTable" roleURI="http://www.vogenx.com/role/ScheduleofSegmentLossandSignificantExpenseTable"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ScheduleofChangeinFairValueasDeterminedbytheLevel3InputsTable" roleURI="http://www.vogenx.com/role/ScheduleofChangeinFairValueasDeterminedbytheLevel3InputsTable"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ScheduleofQuantitativeInformationAbouttheInputsandValuationMethodologiesTable" roleURI="http://www.vogenx.com/role/ScheduleofQuantitativeInformationAbouttheInputsandValuationMethodologiesTable"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ScheduleofReconcilesNetLossandtheSecuritiesUsedtoCalculateWeightedAverageSharesTable" roleURI="http://www.vogenx.com/role/ScheduleofReconcilesNetLossandtheSecuritiesUsedtoCalculateWeightedAverageSharesTable"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ScheduleofNetLossPerShareDuetotheirAntiDilutiveEffectTable" roleURI="http://www.vogenx.com/role/ScheduleofNetLossPerShareDuetotheirAntiDilutiveEffectTable"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_SummaryofSignificantAccountingPoliciesDetails" roleURI="http://www.vogenx.com/role/SummaryofSignificantAccountingPoliciesDetails"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_AccruedExpensesDetails" roleURI="http://www.vogenx.com/role/AccruedExpensesDetails"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_ConvertiblePromissoryNotesPayableRelatedPartyDetails" roleURI="http://www.vogenx.com/role/ConvertiblePromissoryNotesPayableRelatedPartyDetails"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_WarrantsDetails" roleURI="http://www.vogenx.com/role/WarrantsDetails"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_StockholdersDeficitDetails" roleURI="http://www.vogenx.com/role/StockholdersDeficitDetails"/>
  <roleRef xlink:type="simple" xlink:href="vogx-20260630.xsd#vogx_r_NetLossPerCommonShareDetails" roleURI="http://www.vogenx.com/role/NetLossPerCommonShareDetails"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all"/>
  <definitionLink xlink:role="http://www.vogenx.com/role/ConsolidatedBalanceSheet" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredOfferingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredOfferingCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_DeferredOfferingCosts" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AssetsCurrent" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_Assets" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AccountsPayableCurrent" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilitiesNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_DerivativeLiabilitiesNoncurrent" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConvertibleNotesPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleNotesPayableCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_ConvertibleNotesPayableCurrent" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesCurrent" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Liabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_Liabilities" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommitmentsAndContingencies" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockValue" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockValue" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AdditionalPaidInCapital" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="15" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StockholdersEquity" order="16" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" order="17" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ConsolidatedBalanceSheet_Parentheticals" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesIssued" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesAuthorized" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesIssued" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesOutstanding" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ConsolidatedIncomeStatement" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpense" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_GeneralAndAdministrativeExpense" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingExpenses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_OperatingExpenses" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAdjustmentOfWarrants" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_FairValueAdjustmentOfWarrants" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ChangeInFairValueOfConvertiblePromissoryNotesPayableRelatedParty" xlink:href="vogx-20260630.xsd#vogx_ChangeInFairValueOfConvertiblePromissoryNotesPayableRelatedParty"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="vogx_ChangeInFairValueOfConvertiblePromissoryNotesPayableRelatedParty" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentIncomeInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterest"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InvestmentIncomeInterest" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NonoperatingIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NonoperatingIncomeExpense" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NetIncomeLoss" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EarningsPerShareBasic" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" order="11" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ShareholdersEquityType2or3" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AdditionalPaidInCapitalMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_RetainedEarningsMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_SeriesAConvertibleMember" xlink:href="vogx-20260630.xsd#vogx_SeriesAConvertibleMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="vogx_SeriesAConvertibleMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesOutstanding" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquity" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ConsolidatedCashFlow" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetIncomeLoss" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ChangeInFairValueOfConvertiblePromissoryNotesPayableRelatedParty" xlink:href="vogx-20260630.xsd#vogx_ChangeInFairValueOfConvertiblePromissoryNotesPayableRelatedParty"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="vogx_ChangeInFairValueOfConvertiblePromissoryNotesPayableRelatedParty" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAdjustmentOfWarrants" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_FairValueAdjustmentOfWarrants" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_DeferredOfferingCost" xlink:href="vogx-20260630.xsd#vogx_DeferredOfferingCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="vogx_DeferredOfferingCost" order="12" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/OrganizationandNatureofBusiness" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/SummaryofSignificantAccountingPolicies" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SignificantAccountingPoliciesTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/AccruedExpenses" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_PayablesAndAccrualsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PayablesAndAccrualsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ConvertiblePromissoryNotesPayableRelatedParty" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/Warrants" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_WarrantsDisclosureAbstract" xlink:href="vogx-20260630.xsd#vogx_WarrantsDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantsDisclosureTextBlock" xlink:href="vogx-20260630.xsd#vogx_WarrantsDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDisclosureAbstract" xlink:to="vogx_WarrantsDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/StockholdersDeficit" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityNoteAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/NetLossPerCommonShare" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/AccountingPoliciesByPolicy" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_LiquidityPolicyTextBlock" xlink:href="vogx-20260630.xsd#vogx_LiquidityPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="vogx_LiquidityPolicyTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ReverseStockSplitPolicyTextBlock" xlink:href="vogx-20260630.xsd#vogx_ReverseStockSplitPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="vogx_ReverseStockSplitPolicyTextBlock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_InitialPublicOfferingPolicyTextBlock" xlink:href="vogx-20260630.xsd#vogx_InitialPublicOfferingPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="vogx_InitialPublicOfferingPolicyTextBlock" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ReclassificationsPolicyTextBlock" xlink:href="vogx-20260630.xsd#vogx_ReclassificationsPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="vogx_ReclassificationsPolicyTextBlock" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_SegmentReportingPolicyPolicyTextBlock" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredChargesPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredChargesPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_DeferredChargesPolicyTextBlock" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" order="8" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/SummaryofSignificantAccountingPoliciesTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/NetLossPerCommonShareTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ScheduleofSegmentLossandSignificantExpenseTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_ScheduleOfSegmentLossAndSignificantExpenseAbstract" xlink:href="vogx-20260630.xsd#vogx_ScheduleOfSegmentLossAndSignificantExpenseAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfSegmentLossAndSignificantExpenseAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpense" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfSegmentLossAndSignificantExpenseAbstract" xlink:to="us-gaap_GeneralAndAdministrativeExpense" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherNonoperatingIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfSegmentLossAndSignificantExpenseAbstract" xlink:to="us-gaap_OtherNonoperatingIncomeExpense" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfSegmentLossAndSignificantExpenseAbstract" xlink:to="us-gaap_NetIncomeLoss" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ScheduleofChangeinFairValueasDeterminedbytheLevel3InputsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsLineItems" xlink:href="vogx-20260630.xsd#vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsLineItems"/>
    <loc xlink:type="locator" xlink:label="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsTable" xlink:href="vogx-20260630.xsd#vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsLineItems" xlink:to="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByAssetClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsTable" xlink:to="us-gaap_FairValueByAssetClassAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantLiabilityMember" xlink:href="vogx-20260630.xsd#vogx_WarrantLiabilityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="vogx_WarrantLiabilityMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ConvertiblePromissoryNotesPayableRelatedPartyMember" xlink:href="vogx-20260630.xsd#vogx_ConvertiblePromissoryNotesPayableRelatedPartyMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="vogx_ConvertiblePromissoryNotesPayableRelatedPartyMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueOptionChangesInFairValueGainLoss1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesScheduleofChangeinFairValueasDeterminedbytheLevel3InputsDetailsLineItems" xlink:to="us-gaap_FairValueOptionChangesInFairValueGainLoss1" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ScheduleofQuantitativeInformationAbouttheInputsandValuationMethodologiesTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ValuationTechniqueAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_ValuationTechniqueAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ValuationTechniqueDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ValuationTechniqueDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="srt_RangeAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember_0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_MeasurementInputTypeAxis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputCreditSpreadMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputCreditSpreadMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputCreditSpreadMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputRiskFreeInterestRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputRiskFreeInterestRateMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputExpectedDividendPaymentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputExpectedDividendPaymentMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputExpectedDividendPaymentMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputExpectedTermMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputExpectedTermMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputExpectedTermMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputPriceVolatilityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputPriceVolatilityMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputSharePriceMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputSharePriceMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputSharePriceMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputExercisePriceMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputExercisePriceMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputExercisePriceMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ConvertiblePromissoryNotesPayableMember" xlink:href="vogx-20260630.xsd#vogx_ConvertiblePromissoryNotesPayableMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="vogx_ConvertiblePromissoryNotesPayableMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantLiabilityMember" xlink:href="vogx-20260630.xsd#vogx_WarrantLiabilityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="vogx_WarrantLiabilityMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ProbabilityWeightedAverageReturnMethodMember" xlink:href="vogx-20260630.xsd#vogx_ProbabilityWeightedAverageReturnMethodMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="vogx_ProbabilityWeightedAverageReturnMethodMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BlackScholesMertonModelMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BlackScholesMertonModelMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_BlackScholesMertonModelMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMeasurementInput" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentMeasurementInput"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_DebtInstrumentMeasurementInput" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ScheduleofReconcilesNetLossandtheSecuritiesUsedtoCalculateWeightedAverageSharesTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:href="vogx-20260630.xsd#vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:to="us-gaap_NetIncomeLoss" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:to="us-gaap_CommonStockSharesIssued" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:to="us-gaap_EarningsPerShareBasic" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ScheduleOfReconcilesNetLossAndTheSecuritiesUsedToCalculateWeightedAverageSharesAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" order="5" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ScheduleofNetLossPerShareDuetotheirAntiDilutiveEffectTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_SeriesAConvertiblePreferredStockMember" xlink:href="vogx-20260630.xsd#vogx_SeriesAConvertiblePreferredStockMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="vogx_SeriesAConvertiblePreferredStockMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EmployeeStockOptionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_EmployeeStockOptionMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WarrantMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_WarrantMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/SummaryofSignificantAccountingPoliciesDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:href="vogx-20260630.xsd#vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems"/>
    <loc xlink:type="locator" xlink:label="vogx_SummaryofSignificantAccountingPoliciesDetailsTable" xlink:href="vogx-20260630.xsd#vogx_SummaryofSignificantAccountingPoliciesDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="vogx_SummaryofSignificantAccountingPoliciesDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsTable" xlink:to="us-gaap_SubsequentEventTypeAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IPOMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_UndesignatedPreferredStockSharesAuthorized" xlink:href="vogx-20260630.xsd#vogx_UndesignatedPreferredStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="vogx_UndesignatedPreferredStockSharesAuthorized" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_UndesignatedPreferredStockParValue" xlink:href="vogx-20260630.xsd#vogx_UndesignatedPreferredStockParValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="vogx_UndesignatedPreferredStockParValue" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NumberOfReportableSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_NumberOfReportableSegments" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredOfferingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredOfferingCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_DeferredOfferingCosts" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_AccountsPayableCurrentAndNoncurrent" order="14" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/AccruedExpensesDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_PayablesAndAccrualsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PayablesAndAccrualsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCashAwardGrantedAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCashAwardGrantedAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_DeferredCompensationArrangementWithIndividualCashAwardGrantedAmount" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedBonusesCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedBonusesCurrentAndNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_AccruedBonusesCurrentAndNoncurrent" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoninterestExpenseDirectorsFees" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseDirectorsFees"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_NoninterestExpenseDirectorsFees" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/ConvertiblePromissoryNotesPayableRelatedPartyDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:href="vogx-20260630.xsd#vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems"/>
    <loc xlink:type="locator" xlink:label="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsTable" xlink:href="vogx-20260630.xsd#vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsTable" xlink:to="us-gaap_RelatedPartyTransactionAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionAxis" xlink:to="us-gaap_RelatedPartyTransactionDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionAxis" xlink:to="us-gaap_RelatedPartyTransactionDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IPOMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IPOMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionDomain" xlink:to="us-gaap_RelatedPartyMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtConversionConvertedInstrumentRate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtConversionConvertedInstrumentRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentRate" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentTerm" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_DebtInstrumentTerm" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateIncreaseDecrease"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateIncreaseDecrease" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConvertibleNotesPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertibleNotesPayable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_ConvertibleNotesPayable" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_PercentageOfPublicOfferingPrice" xlink:href="vogx-20260630.xsd#vogx_PercentageOfPublicOfferingPrice"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_ConvertiblePromissoryNotesPayableRelatedPartyDetailsLineItems" xlink:to="vogx_PercentageOfPublicOfferingPrice" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/WarrantsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_WarrantsDetailsLineItems" xlink:href="vogx-20260630.xsd#vogx_WarrantsDetailsLineItems"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantsDetailsTable" xlink:href="vogx-20260630.xsd#vogx_WarrantsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="vogx_WarrantsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_WarrantsDetailsTable" xlink:to="us-gaap_ClassOfWarrantOrRightAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantsClassifiedAsEquityMember" xlink:href="vogx-20260630.xsd#vogx_WarrantsClassifiedAsEquityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="vogx_WarrantsClassifiedAsEquityMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantsClassifiedAsLiabilitiesMember" xlink:href="vogx-20260630.xsd#vogx_WarrantsClassifiedAsLiabilitiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="vogx_WarrantsClassifiedAsLiabilitiesMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_ClassOfWarrantOrRightIssued" xlink:href="vogx-20260630.xsd#vogx_ClassOfWarrantOrRightIssued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="vogx_ClassOfWarrantOrRightIssued" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="us-gaap_WarrantsAndRightsOutstandingTerm" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_WarrantsToPurchaseCommonStock" xlink:href="vogx-20260630.xsd#vogx_WarrantsToPurchaseCommonStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="vogx_WarrantsToPurchaseCommonStock" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_WarrantsDetailsLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/StockholdersDeficitDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="vogx_StockholdersDeficitDetailsLineItems" xlink:href="vogx-20260630.xsd#vogx_StockholdersDeficitDetailsLineItems"/>
    <loc xlink:type="locator" xlink:label="vogx_StockholdersDeficitDetailsTable" xlink:href="vogx-20260630.xsd#vogx_StockholdersDeficitDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="vogx_StockholdersDeficitDetailsLineItems" xlink:to="vogx_StockholdersDeficitDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="vogx_StockholdersDeficitDetailsTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SeriesAPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_StockholdersDeficitDetailsLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_StockholdersDeficitDetailsLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="vogx_DescriptionOfSeriesAConvertiblePreferredStock" xlink:href="vogx-20260630.xsd#vogx_DescriptionOfSeriesAConvertiblePreferredStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_StockholdersDeficitDetailsLineItems" xlink:to="vogx_DescriptionOfSeriesAConvertiblePreferredStock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockConvertibleConversionPrice" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockConvertibleConversionPrice"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="vogx_StockholdersDeficitDetailsLineItems" xlink:to="us-gaap_PreferredStockConvertibleConversionPrice" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.vogenx.com/role/NetLossPerCommonShareDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <loc xlink:type="locator" xlink:label="vogx_PrefundedWarrantsIssued" xlink:href="vogx-20260630.xsd#vogx_PrefundedWarrantsIssued"/>
<!-- [WMV7][eZaUxteu1JPOR2tioExsg+a/MgIHBH2ZlHTVJZ319o4vC2HFU5aS+ed0LBJjF47BAKi1K3DmnhOToTBWz+FsNire3UR2RRnnrFAj1fTckkchNocX0NRh3SbUnsbQcEIOMU12J4uTMbhYUEXS31iCdU3kSJlLZbCn3P87Pde57wsfQ2r2XTKKlYSj23ZL4q0xSTZLsCgcSCtrgVTux8Pbw2s89yQjsSfKyqupVizg3Z29ItrEuFo3uRhuP+7NBh6HvstCiHJ2Op8tH5ChFxmtL5EQngPkwfZH9rspcvrLQowxxFDk4nBagw==] CSR-->
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="vogx_PrefundedWarrantsIssued" order="0" xbrldt:closed="true"/>
  </definitionLink>
</linkbase>
