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  <xsd:element id="ymab_ReserveForDiscountsAndAllowancesTableTextBlock" name="ReserveForDiscountsAndAllowancesTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="ymab_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsRemainingPercentage" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsRemainingPercentage" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" />
  <xsd:element id="ymab_ReservesForDiscountsAndAllowancesRollForward" name="ReservesForDiscountsAndAllowancesRollForward" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="ymab_ReserveForDiscountsBalance" name="ReserveForDiscountsBalance" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="ymab_ReserveForDiscountsAdditions" name="ReserveForDiscountsAdditions" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="ymab_ReserveForDiscountsReduction" name="ReserveForDiscountsReduction" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="ymab_SalesReturnLiabilityBalance" name="SalesReturnLiabilityBalance" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="ymab_SalesReturnLiabilityAdditions" name="SalesReturnLiabilityAdditions" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="ymab_SalesReturnLiabilityReduction" name="SalesReturnLiabilityReduction" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="ymab_ReservesAndAllowancesBalance" name="ReservesAndAllowancesBalance" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="ymab_ReservesAndAllowancesAdditions" name="ReservesAndAllowancesAdditions" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="ymab_ReservesAndAllowancesReductions" name="ReservesAndAllowancesReductions" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="ymab_FinancialStatementAccruedLiabilitiesMember" name="FinancialStatementAccruedLiabilitiesMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="ymab_FinancialStatementAccountsReceivableMember" name="FinancialStatementAccountsReceivableMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <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="ArrangementOtherThanCollaborativeTimeBasedMilestoneAccrualPeriod" id="ymab_ArrangementOtherThanCollaborativeTimeBasedMilestoneAccrualPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <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="AccruedLiabilitiesRelatedPartiesCurrent" id="ymab_AccruedLiabilitiesRelatedPartiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="AreaOfRealEstatePropertyAdditionalArea" id="ymab_AreaOfRealEstatePropertyAdditionalArea" type="dtr-types:areaItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="ArrangementOtherThanCollaborativeClinicalMilestonePaymentsDueAccruedLiabilitiesCurrent" id="ymab_ArrangementOtherThanCollaborativeClinicalMilestonePaymentsDueAccruedLiabilitiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <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="CompensationExpenseEquityAwardAgreementShareBasedCompensation" id="ymab_CompensationExpenseEquityAwardAgreementShareBasedCompensation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
</xsd:schema>
