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  <xsd:element name="RoyaltyExpenseExcludingCostsIncludedInCostOfGoodsAndServicesSold" id="ymab_RoyaltyExpenseExcludingCostsIncludedInCostOfGoodsAndServicesSold" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ThreeCustomersMember" id="ymab_ThreeCustomersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ContractualAllowanceAndGovernmentRebateLiabilityBalance" id="ymab_ContractualAllowanceAndGovernmentRebateLiabilityBalance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ContractualAllowanceAndGovernmentRebateLiabilityAdditions" id="ymab_ContractualAllowanceAndGovernmentRebateLiabilityAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ContractualAllowanceAndGovernmentRebateLiabilityReduction" id="ymab_ContractualAllowanceAndGovernmentRebateLiabilityReduction" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="TakedaIsraelMember" id="ymab_TakedaIsraelMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LicenseAndDistributionArrangementMember" id="ymab_LicenseAndDistributionArrangementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DistributionArrangementMember" id="ymab_DistributionArrangementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="IntangibleAssetsCostsIncurredButNotYetPaid" id="ymab_IntangibleAssetsCostsIncurredButNotYetPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="IntangibleAssetsDisclosureAbstract" id="ymab_IntangibleAssetsDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="RevenueAbstract" id="ymab_RevenueAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="PaymentTermsDiscountForPromptPaymentPercent" id="ymab_PaymentTermsDiscountForPromptPaymentPercent" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="AsdMember" id="ymab_AsdMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InventoryCurrentAndNoncurrentTable" id="ymab_InventoryCurrentAndNoncurrentTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InventoryCurrentAndNoncurrentLineItems" id="ymab_InventoryCurrentAndNoncurrentLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ScheduleOfInventoryCurrentAndNoncurrentTableTextBlock" id="ymab_ScheduleOfInventoryCurrentAndNoncurrentTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="InventoryCurrentAndNoncurrent" id="ymab_InventoryCurrentAndNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="FiniteLivedIntangibleAssetExpectedAmortizationCurrentFiscalYear" id="ymab_FiniteLivedIntangibleAssetExpectedAmortizationCurrentFiscalYear" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="AreaOfRealEstatePropertyAdditionalArea" id="ymab_AreaOfRealEstatePropertyAdditionalArea" type="dtr-types:areaItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="CompensationExpenseEmploymentAgreementSalariesAndCertainBenefitsContinuation" id="ymab_CompensationExpenseEmploymentAgreementSalariesAndCertainBenefitsContinuation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="CompensationExpenseEmploymentAndEquityAwardAgreementSalariesAndCertainBenefitsContinuationAndShareBasedCompensation" id="ymab_CompensationExpenseEmploymentAndEquityAwardAgreementSalariesAndCertainBenefitsContinuationAndShareBasedCompensation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="FairValueAssetsLevel1ToLevel2TransfersAmount1" id="ymab_FairValueAssetsLevel1ToLevel2TransfersAmount1" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="FairValueAssetsLevel2ToLevel1TransfersAmount1" id="ymab_FairValueAssetsLevel2ToLevel1TransfersAmount1" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ScheduleOfCompensationArrangementWithIndividualTable" id="ymab_ScheduleOfCompensationArrangementWithIndividualTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CompensationArrangementWithIndividualLineItems" id="ymab_CompensationArrangementWithIndividualLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ChiefExecutiveOfficerFormerMember" id="ymab_ChiefExecutiveOfficerFormerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LicenseMilestoneMember" id="ymab_LicenseMilestoneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="IndividualsUnderRetentionProgramMember" id="ymab_IndividualsUnderRetentionProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="AcquisitionOfTreasurySharesUponRepaymentOfSecuredPromissoryNote" id="ymab_AcquisitionOfTreasurySharesUponRepaymentOfSecuredPromissoryNote" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ReservesForDiscountsAndAllowancesChangeInEstimate" id="ymab_ReservesForDiscountsAndAllowancesChangeInEstimate" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ContractualAllowanceAndGovernmentRebateChangeInEstimate" id="ymab_ContractualAllowanceAndGovernmentRebateChangeInEstimate" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="NumberOfIndividualsRepaymentOfNote" id="ymab_NumberOfIndividualsRepaymentOfNote" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="LawsuitFiledByShareholderU.s.DistrictCourtSouthernDistrictOfNewYorkAugust252021Member" id="ymab_LawsuitFiledByShareholderU.s.DistrictCourtSouthernDistrictOfNewYorkAugust252021Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfStockholdersThatFiledLawsuit" id="ymab_NumberOfStockholdersThatFiledLawsuit" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="ArrangementOtherThanCollaborativeRegulatoryMilestonePaymentsReceivable" id="ymab_ArrangementOtherThanCollaborativeRegulatoryMilestonePaymentsReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ArrangementOtherThanCollaborativeSalesBasedMilestonePaymentsReceivable" id="ymab_ArrangementOtherThanCollaborativeSalesBasedMilestonePaymentsReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="AssetImpairmentChargesNoteReceivable" id="ymab_AssetImpairmentChargesNoteReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ForeignCurrencyTransactionGainLossBeforeTaxAndOtherTransactions" id="ymab_ForeignCurrencyTransactionGainLossBeforeTaxAndOtherTransactions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ArrangementOtherThanCollaborativeAnnualMinimumRoyaltiesPayablePatentIssued" id="ymab_ArrangementOtherThanCollaborativeAnnualMinimumRoyaltiesPayablePatentIssued" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LicenseAgreementMember" id="ymab_LicenseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="MskAndMabvaxMember" id="ymab_MskAndMabvaxMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="MskAndMitMember" id="ymab_MskAndMitMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WepClinicalLimitedMember" id="ymab_WepClinicalLimitedMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InterestIncomeExpenseAndOtherNonoperatingIncomeExpense" id="ymab_InterestIncomeExpenseAndOtherNonoperatingIncomeExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="NumberOfStockGrantsAgreements" id="ymab_NumberOfStockGrantsAgreements" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="SwixxBiopharmaAgMember" id="ymab_SwixxBiopharmaAgMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CertainSeniorExecutivesMember" id="ymab_CertainSeniorExecutivesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresTwoAbstract" id="ymab_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresTwoAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="Quarter32023Member" id="ymab_Quarter32023Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
</xsd:schema>
