<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2022-02-16T09:37:03.8475807+00:00 -->
<!-- Version            : 5.0.1.728 -->
<!-- Package ID         : d608d17a1b02493ba16a0a337f653a5a -->
<!-- Copyright (c) 2022 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="alks_LongTermInvestmentSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" name="LongTermInvestmentSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_LongTermInvestmentSecuritiesContinuousUnrealizedLossPositionMoreThan12MonthsAggregateLosses" name="LongTermInvestmentSecuritiesContinuousUnrealizedLossPositionMoreThan12MonthsAggregateLosses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_LongTermInvestmentsMember" name="LongTermInvestmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_FixedTermDepositAccountMember" name="FixedTermDepositAccountMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_SynchronicityPharmaIncMember" name="SynchronicityPharmaIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_ConvertiblePromissoryNotesMember" name="ConvertiblePromissoryNotesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_FountainHealthcarePartnersIiLpOfIrelandMember" name="FountainHealthcarePartnersIiLpOfIrelandMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_CommitmentOnEquityMethodInvestments" name="CommitmentOnEquityMethodInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_EquityMethodCommitment" name="EquityMethodCommitment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_FundingCommitmentAsPercentageOfPartnershipsFunding" name="FundingCommitmentAsPercentageOfPartnershipsFunding" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="alks_NumberOfPortfolioSold" name="NumberOfPortfolioSold" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_MarketableSecuritiesRealizedGain" name="MarketableSecuritiesRealizedGain" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_MarketableSecuritiesRealizedLoss" name="MarketableSecuritiesRealizedLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_FairValueRecurringBasisAssetsOrLiabilitiesTransfersBetweenLevelOneToLevelTwo" name="FairValueRecurringBasisAssetsOrLiabilitiesTransfersBetweenLevelOneToLevelTwo" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_FairValueRecurringBasisAssetsOrLiabilitiesTransfersBetweenLevelTwoToLevelOne" name="FairValueRecurringBasisAssetsOrLiabilitiesTransfersBetweenLevelTwoToLevelOne" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_TwentyTwentySixTermLoansMember" name="TwentyTwentySixTermLoansMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_TwentyTwentyThreeTermLoansMember" name="TwentyTwentyThreeTermLoansMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetImpairmentOfCorporateDebtSecurity" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetImpairmentOfCorporateDebtSecurity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_FairValueOfContingentConsiderationMember" name="FairValueOfContingentConsiderationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_AdditionalMilestonePaymentsReceived" name="AdditionalMilestonePaymentsReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_NumberOfEqualAnnualInstallmentsMilestonePayment" name="NumberOfEqualAnnualInstallmentsMilestonePayment" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="alks_PercentageOfDiscountRecoveryRate" name="PercentageOfDiscountRecoveryRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="alks_WeightingPercentageOfDiscountRate" name="WeightingPercentageOfDiscountRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="alks_WeightingPercentageOfUndiscountedValues" name="WeightingPercentageOfUndiscountedValues" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="alks_InventoryFinishedGoodsNetOfReservesLocatedAtThirdPartyWarehouseAndShippingServiceProvider" name="InventoryFinishedGoodsNetOfReservesLocatedAtThirdPartyWarehouseAndShippingServiceProvider" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_FIFOInventoryAdvanceCapitalizationAmount" name="FIFOInventoryAdvanceCapitalizationAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_NumberOfOperatingLeases" name="NumberOfOperatingLeases" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="alks_BasePremisesMember" name="BasePremisesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_AdditionalPremisesMember" name="AdditionalPremisesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_LeaseAgreementCommencementDate" name="LeaseAgreementCommencementDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_LeaseAgreementLeaseRenewalTerm" name="LeaseAgreementLeaseRenewalTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_OperatingLeaseProvisionForExtensionOfTerm" name="OperatingLeaseProvisionForExtensionOfTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_LeaseAgreementCommencementPeriod" name="LeaseAgreementCommencementPeriod" type="xbrli:gYearMonthItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_OperatingLeaseExpirationYear" name="OperatingLeaseExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_AccruedSalesDiscountsAllowancesAndReserves" name="AccruedSalesDiscountsAllowancesAndReserves" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_DebtInstrumentVariableRateBasisFloor" name="DebtInstrumentVariableRateBasisFloor" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_DebtInstrumentIncrementalCapacitySubjectToSatisfactionOfCertainConditions" name="DebtInstrumentIncrementalCapacitySubjectToSatisfactionOfCertainConditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_ThresholdPercentageComparisonPresentValueRemainingCashFlows" name="ThresholdPercentageComparisonPresentValueRemainingCashFlows" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_NumberOfLenderHoldingPercentageOfOutstandingAmount" name="NumberOfLenderHoldingPercentageOfOutstandingAmount" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_PercentageOfOutstandingPrincipalAmountHeldByLender" name="PercentageOfOutstandingPrincipalAmountHeldByLender" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_ScheduledMaturitiesOfTermLoanTwoThousandAndTwentySix" name="ScheduledMaturitiesOfTermLoanTwoThousandAndTwentySix" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_StockOptionAndIncentivePlan2018Member" name="StockOptionAndIncentivePlan2018Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansUnderWhichAwardsAreCurrentlyMade" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansUnderWhichAwardsAreCurrentlyMade" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansUnderWhichNoFurtherAwardsWillBeMade" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPlansUnderWhichNoFurtherAwardsWillBeMade" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentOtherThanOptionsCountAgainstNumberOfSharesAvailableForGrantRatio" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentOtherThanOptionsCountAgainstNumberOfSharesAvailableForGrantRatio" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageExercisePriceAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_UpfrontCashPayment" name="UpfrontCashPayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_UpfrontCashFuturePayments" name="UpfrontCashFuturePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_BusinessAcquisitionDateOfAcquisitionCompleted" name="BusinessAcquisitionDateOfAcquisitionCompleted" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_RodinTherapeuticsIncorporationMember" name="RodinTherapeuticsIncorporationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_AchievementOfSpecifiedClinicalMilestonesMember" name="AchievementOfSpecifiedClinicalMilestonesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_AchievementOfRegulatoryMilestonesMember" name="AchievementOfRegulatoryMilestonesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_AttainmentOfSalesThresholdsMember" name="AttainmentOfSalesThresholdsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_BusinessCombinationResearchAndDevelopmentExpense" name="BusinessCombinationResearchAndDevelopmentExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_MilestonesFuturePayments" name="MilestonesFuturePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayableAndAccruedExpenses" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayableAndAccruedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesShortTerm" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesShortTerm" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesLongTerm" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesLongTerm" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_CollaborativeArrangementRoyaltyRate" name="CollaborativeArrangementRoyaltyRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementPatentRoyaltyRate" name="CollaborativeArrangementPatentRoyaltyRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementKnowHowRoyaltyRate" name="CollaborativeArrangementKnowHowRoyaltyRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementNetSalesTiedToKnowHowRoyalty" name="CollaborativeArrangementNetSalesTiedToKnowHowRoyalty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_CollaborativeArrangementPeriodAfterDateOfFirstCommercialSaleOfProductForExpirationOfAgreement" name="CollaborativeArrangementPeriodAfterDateOfFirstCommercialSaleOfProductForExpirationOfAgreement" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementKnowHowRoyaltyRateResets" name="CollaborativeArrangementKnowHowRoyaltyRateResets" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_LicenseAgreementMember" name="LicenseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_OHRisperidonePalimateMember" name="OHRisperidonePalimateMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_NetSalesBelow250MillionMember" name="NetSalesBelow250MillionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_NetSalesBetween250And500MillionMember" name="NetSalesBetween250And500MillionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_NetSalesGreaterThan500MillionMember" name="NetSalesGreaterThan500MillionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_ManufacturingAndSupplyAgreementMember" name="ManufacturingAndSupplyAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_NumberOfLicenseAgreements" name="NumberOfLicenseAgreements" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementEffectiveNoticePeriodRequiredToBeServedForTerminationOfAgreement" name="CollaborativeArrangementEffectiveNoticePeriodRequiredToBeServedForTerminationOfAgreement" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementPeriodForResolvingDefaultOrBreachAfterReceiptOfNoticeForTerminationOfAgreement" name="CollaborativeArrangementPeriodForResolvingDefaultOrBreachAfterReceiptOfNoticeForTerminationOfAgreement" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CollaborativeArrangementRoyaltyRateUponTerminationOfRelatedAgreement" name="CollaborativeArrangementRoyaltyRateUponTerminationOfRelatedAgreement" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_IncomeTaxesLineItems" name="IncomeTaxesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_IncomeTaxesTable" name="IncomeTaxesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_IncomeTaxesPayableOnRepatriationOfUnremittedEarnings" name="IncomeTaxesPayableOnRepatriationOfUnremittedEarnings" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="alks_DeferredTaxAssetsTaxCreditCarryforwardsState" name="DeferredTaxAssetsTaxCreditCarryforwardsState" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="alks_PeriodAfterLossCarryforwardsUtilizedThatTaxReturnsRemainOpenToExamination" name="PeriodAfterLossCarryforwardsUtilizedThatTaxReturnsRemainOpenToExamination" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="alks_CommitmentsAndContingenciesLineItems" name="CommitmentsAndContingenciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_CommitmentsAndContingenciesTable" name="CommitmentsAndContingenciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_CapitalPurchaseCommitmentsMember" name="CapitalPurchaseCommitmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="alks_MaximumPeriodBeforeFDACanApprovePatentRequest" name="MaximumPeriodBeforeFDACanApprovePatentRequest" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
</xsd:schema>
