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  <xsd:element id="asmb_CollaborativeAndLicenseArrangementDisclosureTextBlock" name="CollaborativeAndLicenseArrangementDisclosureTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_IssuanceOfCommonStockUponCashlessExerciseOfPreFundedWarrants" name="IssuanceOfCommonStockUponCashlessExerciseOfPreFundedWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_ShareBasedCompensationArrangementFairValueAssumptionsExercisePrice" name="ShareBasedCompensationArrangementFairValueAssumptionsExercisePrice" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_RetentionBonusesCosts" name="RetentionBonusesCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_CashEquivalentsAtCarryingValueAndAvailableForSaleDebtSecuritiesAmortizedCost" name="CashEquivalentsAtCarryingValueAndAvailableForSaleDebtSecuritiesAmortizedCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_IncreaseDecreaseInOperatingLeaseLiabilities" name="IncreaseDecreaseInOperatingLeaseLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_CashAndCashEquivalentGrossUnrealizedGain" name="CashAndCashEquivalentGrossUnrealizedGain" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_RestructuringAndRelatedCostIncurredCostBenefit" name="RestructuringAndRelatedCostIncurredCostBenefit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_CashAndCashEquivalentGrossUnrealizedLoss" name="CashAndCashEquivalentGrossUnrealizedLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_RetainedEmployeesMember" name="RetainedEmployeesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_RestructuringOneTimeTerminationCost" name="RestructuringOneTimeTerminationCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_InitialPublicOfferingValueOfSharesAuthorized" name="InitialPublicOfferingValueOfSharesAuthorized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_NonExecutiveOfficersMember" name="NonExecutiveOfficersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_EmployeeSeveranceAndRelatedBenefitsMember" name="EmployeeSeveranceAndRelatedBenefitsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTaxCurrent" name="AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTaxCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_AccretionAmortizationOfInvestmentsInMarketableDebtSecurities" name="AccretionAmortizationOfInvestmentsInMarketableDebtSecurities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_FairValueAssetsBetweenLevelsTransfersAmount" name="FairValueAssetsBetweenLevelsTransfersAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_SuccessBasedMilestonesPayment" name="SuccessBasedMilestonesPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_AvailableForSaleSecuritiesMaturityTerm" name="AvailableForSaleSecuritiesMaturityTerm" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_MilestonesAndResearchAgreementsTextBlock" name="MilestonesAndResearchAgreementsTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_AccruedResearchAndDevelopmentExpensesCurrent" name="AccruedResearchAndDevelopmentExpensesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_USAndForeignCommercialPaperMember" name="USAndForeignCommercialPaperMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_LongTermMarketableSecuritiesMember" name="LongTermMarketableSecuritiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_NumberOfAdditionalUndisclosedViralTargets" name="NumberOfAdditionalUndisclosedViralTargets" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_ProceedsFromIssuanceOfCommonStockUnderEmployeeStockPurchasePlan" name="ProceedsFromIssuanceOfCommonStockUnderEmployeeStockPurchasePlan" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTaxNoncurrent" name="AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTaxNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_FairValueMeasurementsAndInvestmentsInMarketableSecuritiesTextBlock" name="FairValueMeasurementsAndInvestmentsInMarketableSecuritiesTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_CommonStockSubjectToPurchaseUnderEmployeeStockPurchaseProgramMember" name="CommonStockSubjectToPurchaseUnderEmployeeStockPurchaseProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_CashEquivalentsAtFairValueAbstract" name="CashEquivalentsAtFairValueAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_OtherRisksAndUncertaintiesPolicyTextBlock" name="OtherRisksAndUncertaintiesPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_AccruedRestructuringChargesCurrent" name="AccruedRestructuringChargesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_NoncashRentExpense" name="NoncashRentExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_ScheduleOfAvailableForSaleSecurities1Table" name="ScheduleOfAvailableForSaleSecurities1Table" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_CumulativeRestructuringCharges" name="CumulativeRestructuringCharges" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_OtherAccruedExpensesMember" name="OtherAccruedExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_RestructuringCostsReversalOfStockBasedCompensationExpense" name="RestructuringCostsReversalOfStockBasedCompensationExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_MilestonesAndResearchAgreementsAbstract" name="MilestonesAndResearchAgreementsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_BeiGeneAgreementMember" name="BeiGeneAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_CapitalizedAndAmortizedCostsPeriod" name="CapitalizedAndAmortizedCostsPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_TwoThousandAndTwentyAtTheMarketOfferingsMember" name="TwoThousandAndTwentyAtTheMarketOfferingsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_SignificantAccountingPoliciesTable" name="SignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_IncreaseDecreaseInAccruedResearchAndDevelopmentExpenses" name="IncreaseDecreaseInAccruedResearchAndDevelopmentExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_ScheduleOfRestructuringChargesTableTextblock" name="ScheduleOfRestructuringChargesTableTextblock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_IncrementalCosts" name="IncrementalCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_NumberOfApprovedProducts" name="NumberOfApprovedProducts" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_AccuredInterestReceivable" name="AccuredInterestReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_PercentageOfCorporateAlternativeMinimumTax" name="PercentageOfCorporateAlternativeMinimumTax" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_AssetImpairmentAndOtherCostsMember" name="AssetImpairmentAndOtherCostsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_RestructuringAndIsExpectedAmountTotal" name="RestructuringAndIsExpectedAmountTotal" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_AccruedRestructuringCharges" name="AccruedRestructuringCharges" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_PercentageOfReductionInWorkforce" name="PercentageOfReductionInWorkforce" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_ScheduleOfAccruedRestructuringChargesTableTextblock" name="ScheduleOfAccruedRestructuringChargesTableTextblock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_IssuanceOfCommonStockUponCashlessExerciseOfPreFundedWarrantsShares" name="IssuanceOfCommonStockUponCashlessExerciseOfPreFundedWarrantsShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTaxCurrent" name="AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTaxCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="asmb_DoorPharmaAgreementMember" name="DoorPharmaAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_SignificantAccountingPoliciesLineItems" name="SignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="asmb_MilestonePaymentDiligenceMaintenanceFees" name="MilestonePaymentDiligenceMaintenanceFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTaxNoncurrent" name="AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTaxNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="asmb_LicenseAgreementTerm" name="LicenseAgreementTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="asmb_ResearchAndDevelopmentFundingCharges" name="ResearchAndDevelopmentFundingCharges" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
</xsd:schema>
