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  <xs:element id="pdli_LiquidationBasisOfAccountingEstimatedCashExpenditureEstimatedDisposalCostsAssertioAsset" abstract="false" name="LiquidationBasisOfAccountingEstimatedCashExpenditureEstimatedDisposalCostsAssertioAsset" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_ChangeInTheValueOfReceivablesFromSalesOfAssetsMember" abstract="true" name="ChangeInTheValueOfReceivablesFromSalesOfAssetsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_NextthirtysixmonthsMemberMember" abstract="true" name="NextthirtysixmonthsMemberMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_CreditAgreementStatedInterestRate" abstract="false" name="CreditAgreementStatedInterestRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationConsiderationToBeReceivedNumberOfQuarterlyInstallments" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationConsiderationToBeReceivedNumberOfQuarterlyInstallments" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pdli_Paymentsforcurrentperiodsales" abstract="false" name="Paymentsforcurrentperiodsales" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Numberofpaymentstobereceived" abstract="false" name="Numberofpaymentstobereceived" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pdli_FortheyearendingDecember312025Member" abstract="true" name="FortheyearendingDecember312025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_DebtInstrumentConvertibleNumberOfInstrumentsHeldTenderedForRepurchase" abstract="false" name="DebtInstrumentConvertibleNumberOfInstrumentsHeldTenderedForRepurchase" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pdli_Allowancesforcurrentperiodsales" abstract="false" name="Allowancesforcurrentperiodsales" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_InitialLoanMember" abstract="true" name="InitialLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_ProceedsReceivedUnderRemediesAvailableForBorrowersBreachOfTerms" abstract="false" name="ProceedsReceivedUnderRemediesAvailableForBorrowersBreachOfTerms" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_AccumulatedOtherComprehensiveIncomeAbstract" abstract="true" name="AccumulatedOtherComprehensiveIncomeAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_FinancingCostsRelatedtoLongtermDebtPolicyTextBlock" abstract="false" name="FinancingCostsRelatedtoLongtermDebtPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_IncomebeforeincometaxesbylocationTableTextBlock" abstract="false" name="IncomebeforeincometaxesbylocationTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_CerdelgaMember" abstract="true" name="CerdelgaMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_DebttypeAxis" abstract="true" name="DebttypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="pdli_IsposalGroupIncludingDiscontinuedOperationContingentConsiderationLicenseFeeRatePeriodOfReceipt" abstract="false" name="IsposalGroupIncludingDiscontinuedOperationContingentConsiderationLicenseFeeRatePeriodOfReceipt" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pdli_EppsMember" abstract="true" name="EppsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingAccountsPayableCurrent" abstract="false" name="LiquidationBasisOfAccountingAccountsPayableCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_DurationOfAgreementWaiveMonthlyRentalAndMinimumMonthlyLicenseFees" abstract="false" name="DurationOfAgreementWaiveMonthlyRentalAndMinimumMonthlyLicenseFees" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pdli_ScheduleofinterestexpenseforDecember2021NotesAbstract" abstract="true" name="ScheduleofinterestexpenseforDecember2021NotesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_PurchasedCallOptionsCost" abstract="false" name="PurchasedCallOptionsCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_ABCMember" abstract="true" name="ABCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Costofinvestmentpershare" abstract="false" name="Costofinvestmentpershare" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:perShareItemType"/>
  <xs:element id="pdli_Tranche2ofnotereceivable" abstract="false" name="Tranche2ofnotereceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_March2015TermLoanMember" abstract="true" name="March2015TermLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingAccountsReceivableFromAssetSalesNet" abstract="false" name="LiquidationBasisOfAccountingAccountsReceivableFromAssetSalesNet" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_KaleoNoteReceivableMember" abstract="true" name="KaleoNoteReceivableMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationConsiderationToBeReceived" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationConsiderationToBeReceived" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Cashflowmodelexpectedroyaltysalesterm" abstract="false" name="Cashflowmodelexpectedroyaltysalesterm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pdli_Warrantsacquired" abstract="false" name="Warrantsacquired" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pdli_CreditAgreementMember" abstract="true" name="CreditAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_RoyaltyAgreementMember" abstract="true" name="RoyaltyAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Purchaseofroyaltyright" abstract="false" name="Purchaseofroyaltyright" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingExpectedCashRealizableValueWarrant" abstract="false" name="LiquidationBasisOfAccountingExpectedCashRealizableValueWarrant" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Tranche1Member" abstract="true" name="Tranche1Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_EstimatedrealtorfeeMember" abstract="true" name="EstimatedrealtorfeeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_February2018NotesMember" abstract="true" name="February2018NotesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Tranche1ofinvestment" abstract="false" name="Tranche1ofinvestment" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="pdli_Federalincometaxrate" abstract="false" name="Federalincometaxrate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_EstimatedTaxOnConvertibleNoteInterestExpense" abstract="false" name="EstimatedTaxOnConvertibleNoteInterestExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Debtdiscountrecordedtodeferredtaxliability" abstract="false" name="Debtdiscountrecordedtodeferredtaxliability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Equityinvestmentsharesheldshares" abstract="false" name="Equityinvestmentsharesheldshares" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pdli_Warrantexerciseprice" abstract="false" name="Warrantexerciseprice" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:perShareItemType"/>
  <xs:element id="pdli_PercentageOfVotingRightsOwnedPriorToDistribution" abstract="false" name="PercentageOfVotingRightsOwnedPriorToDistribution" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_CommonStockUsedToSettleConvertibleDebt" abstract="false" name="CommonStockUsedToSettleConvertibleDebt" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_ProductrevenuePolicyTextBlock" abstract="false" name="ProductrevenuePolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_TermloanandinterestMember" abstract="true" name="TermloanandinterestMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
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  <xs:element id="pdli_Cappedcallunwind" abstract="false" name="Cappedcallunwind" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Tranche2ofinvestment" abstract="false" name="Tranche2ofinvestment" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_RevenuefromContractswithCustomersAbstract" abstract="true" name="RevenuefromContractswithCustomersAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_CarryingvalueandunamortizeddiscountonDecemberTableTextBlock" abstract="false" name="CarryingvalueandunamortizeddiscountonDecemberTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
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  <xs:element id="pdli_CareViewMember" abstract="true" name="CareViewMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_OperatinglosscarryforwardlimitationperiodDomain" abstract="true" name="OperatinglosscarryforwardlimitationperiodDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Investmentestimatedfairvaluepershare" abstract="false" name="Investmentestimatedfairvaluepershare" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:perShareItemType"/>
  <xs:element id="pdli_Computerandofficeequipment" abstract="false" name="Computerandofficeequipment" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationContingentConsiderationLicenseFeeRate" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationContingentConsiderationLicenseFeeRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_AssetsbyGeographicLocationAbstract" abstract="true" name="AssetsbyGeographicLocationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_Queenetal.RoyaltyRevenuesPolicyTextBlock" abstract="false" name="Queenetal.RoyaltyRevenuesPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_ContractassetsTableTextBlock" abstract="false" name="ContractassetsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_ScheduleofinterestexpenseforFebruary2018NotesTableTextBlock" abstract="false" name="ScheduleofinterestexpenseforFebruary2018NotesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingNetAssetsLiabilitiesChangeInAssetsAndLiabilitiesInLiquidationAbstract" abstract="true" name="LiquidationBasisOfAccountingNetAssetsLiabilitiesChangeInAssetsAndLiabilitiesInLiquidationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_IncreaseDecreaseInDisposalCost" abstract="false" name="IncreaseDecreaseInDisposalCost" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_WellstatDiagnosticsMember" abstract="true" name="WellstatDiagnosticsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_LiquidationAccountingSettlementPremium" abstract="false" name="LiquidationAccountingSettlementPremium" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_VBMember" abstract="true" name="VBMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_FairValueMeasurementsAbstract" abstract="true" name="FairValueMeasurementsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_Exchangeofdebt" abstract="false" name="Exchangeofdebt" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_MedicarePartDinsurancecoveragegap" abstract="false" name="MedicarePartDinsurancecoveragegap" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_ChangeinfairvalueofacquiredroyaltyrightsLevel3Rollforward" abstract="false" name="ChangeinfairvalueofacquiredroyaltyrightsLevel3Rollforward" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_RevenuesWaiveMonthlyRentalAndMinimumMonthlyLicenseFees" abstract="false" name="RevenuesWaiveMonthlyRentalAndMinimumMonthlyLicenseFees" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingChangesInNetEquityInLiquidationTableTextBlock" abstract="false" name="LiquidationBasisOfAccountingChangesInNetEquityInLiquidationTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_CashpaidMember" abstract="true" name="CashpaidMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_ForbearancenumberofdaysundertermsofcreditagreementinDuration" abstract="false" name="ForbearancenumberofdaysundertermsofcreditagreementinDuration" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pdli_PercentageOfNetSalesCollateralForSecuredNote" abstract="false" name="PercentageOfNetSalesCollateralForSecuredNote" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
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  <xs:element id="pdli_Changeinfairvalueofacquiredroyaltyrights" abstract="false" name="Changeinfairvalueofacquiredroyaltyrights" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_AuviQMember" abstract="true" name="AuviQMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_BiogenIdecMember" abstract="true" name="BiogenIdecMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_FinancialLiabilitiesAbstract" abstract="true" name="FinancialLiabilitiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_RoyaltyRightsPeriodToGiveNoticeToTerminateLicenseAgreement" abstract="false" name="RoyaltyRightsPeriodToGiveNoticeToTerminateLicenseAgreement" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pdli_Sharesacquired" abstract="false" name="Sharesacquired" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pdli_EstimatedCostToSell" abstract="false" name="EstimatedCostToSell" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_ScheduleofinterestexpenseforDecember2021NotesTableTextBlock" abstract="false" name="ScheduleofinterestexpenseforDecember2021NotesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_ScheduleofcarryingvalueandunamortizeddiscountonFebruary2018NotesTableTextBlock" abstract="false" name="ScheduleofcarryingvalueandunamortizeddiscountonFebruary2018NotesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_EVZIOMember" abstract="true" name="EVZIOMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Reductioninroyaltyrateinpercent" abstract="false" name="Reductioninroyaltyrateinpercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_NexttwelvemonthsMember" abstract="true" name="NexttwelvemonthsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_ScheduleOfOtherLiabilitiesTable" abstract="true" name="ScheduleOfOtherLiabilitiesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pdli_KaleoMember" abstract="true" name="KaleoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_AcquiredRoyaltyRightsPolicyTextBlock" abstract="false" name="AcquiredRoyaltyRightsPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_NumberOfCustomersWaiveMonthlyRentalAndMinimumMonthlyLicenseFees" abstract="false" name="NumberOfCustomersWaiveMonthlyRentalAndMinimumMonthlyLicenseFees" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pdli_Repaymentofconvertiblenoteinterest" abstract="false" name="Repaymentofconvertiblenoteinterest" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_AcelRxMember" abstract="true" name="AcelRxMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_ContractassetsTable" abstract="true" name="ContractassetsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pdli_Warrantunwind" abstract="false" name="Warrantunwind" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_AcquiredrightsMember" abstract="true" name="AcquiredrightsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_ContractLiabilitiesLineItems" abstract="true" name="ContractLiabilitiesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_MckessonMember" abstract="true" name="MckessonMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_PharmaceuticalMember" abstract="true" name="PharmaceuticalMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_NonemployeesMember" abstract="true" name="NonemployeesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
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  <xs:element id="pdli_ScheduleOfAssetsAndLiabilitiesNotRecordedAtFairValueTableTextBlock" abstract="false" name="ScheduleOfAssetsAndLiabilitiesNotRecordedAtFairValueTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
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  <xs:element id="pdli_ProceedsFromSaleOfRoyaltyInterests" abstract="false" name="ProceedsFromSaleOfRoyaltyInterests" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_February2018NotePurchaseCallOptionMember" abstract="true" name="February2018NotePurchaseCallOptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Level3RollforwardDisclosureClassificationDomain" abstract="true" name="Level3RollforwardDisclosureClassificationDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_LegalProceedingsAbstract" abstract="true" name="LegalProceedingsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationAdditionalConsiderationToBeReceivedNumberOfQuarterlyInstallments" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationAdditionalConsiderationToBeReceivedNumberOfQuarterlyInstallments" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pdli_Boardobserverappointed" abstract="false" name="Boardobserverappointed" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationsRoyaltyAssets" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationsRoyaltyAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="pdli_Estimatedmarketinterestrateforsimilarnonconvertibleinstrument" abstract="false" name="Estimatedmarketinterestrateforsimilarnonconvertibleinstrument" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_LicenseandotherMember" abstract="true" name="LicenseandotherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_SalesallowancesDomain" abstract="true" name="SalesallowancesDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Allowancesforpriorperiodsales" abstract="false" name="Allowancesforpriorperiodsales" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_HyperionMember" abstract="true" name="HyperionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_OperatingSegmentNetIncomeLoss" abstract="false" name="OperatingSegmentNetIncomeLoss" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Governmentrebatesandchargebacks" abstract="false" name="Governmentrebatesandchargebacks" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Withheldrelatedtonetsettlement" abstract="false" name="Withheldrelatedtonetsettlement" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pdli_DebtInstrumentConvertibleMaximumClosingPricePercentage" abstract="false" name="DebtInstrumentConvertibleMaximumClosingPricePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationContingentConsiderationPeriodAfterClosingDateForBindingAgreementContingency" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationContingentConsiderationPeriodAfterClosingDateForBindingAgreementContingency" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pdli_ScheduleOfOtherLiabilitiesLineItems" abstract="true" name="ScheduleOfOtherLiabilitiesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingAdoptionAdjustmentsDomain" abstract="true" name="LiquidationBasisOfAccountingAdoptionAdjustmentsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_GovernmentRebatesandChargebacksMember" abstract="true" name="GovernmentRebatesandChargebacksMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_InducementAwardMember" abstract="true" name="InducementAwardMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_IncomegeneratingassetsMember" abstract="true" name="IncomegeneratingassetsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Periodiccontractualpayments" abstract="false" name="Periodiccontractualpayments" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_EquipmentUnderLeaseTableTextBlock" abstract="false" name="EquipmentUnderLeaseTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType"/>
  <xs:element id="pdli_Cappedcallcommonstockrepurchased" abstract="false" name="Cappedcallcommonstockrepurchased" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_UniversityofMichiganMember" abstract="true" name="UniversityofMichiganMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Repurchasepriceuponfundamentalchangeasdescribedin2024Notesindenture" abstract="false" name="Repurchasepriceuponfundamentalchangeasdescribedin2024Notesindenture" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_ProductReturnsMember" abstract="true" name="ProductReturnsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_CustomerConcentrationNarrativeAbstract" abstract="true" name="CustomerConcentrationNarrativeAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_PaymentTypeDomain" abstract="true" name="PaymentTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingChangeInNetAssetsRollForward" abstract="true" name="LiquidationBasisOfAccountingChangeInNetAssetsRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingAccruedLiquidationCostsCurrent" abstract="false" name="LiquidationBasisOfAccountingAccruedLiquidationCostsCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_InterestRateOnNoteReceivable" abstract="false" name="InterestRateOnNoteReceivable" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_KybellaMember" abstract="true" name="KybellaMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_NextsixmonthsMember" abstract="true" name="NextsixmonthsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_RoyaltyrightMember" abstract="true" name="RoyaltyrightMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_ThirdpartyMember" abstract="true" name="ThirdpartyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Productreturn" abstract="false" name="Productreturn" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Repurchasepriceuponfundamentalchangeasdescribedin2021Notesindenture" abstract="false" name="Repurchasepriceuponfundamentalchangeasdescribedin2021Notesindenture" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="pdli_PaymentTypeAxis" abstract="true" name="PaymentTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="pdli_CommitmentToProvideFundingDuringOneHundredTwentydayForbearancePeriod" abstract="false" name="CommitmentToProvideFundingDuringOneHundredTwentydayForbearancePeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingLeaseObligations" abstract="false" name="LiquidationBasisOfAccountingLeaseObligations" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_EmployeesanddirectorsMember" abstract="true" name="EmployeesanddirectorsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_LiquidationBasisOfAccountingEstimatedCashExpenditureDeferredTaxLiabilities" abstract="false" name="LiquidationBasisOfAccountingEstimatedCashExpenditureDeferredTaxLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_Changeinfairvalueofcontingentconsideration" abstract="false" name="Changeinfairvalueofcontingentconsideration" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="pdli_RoyaltyAssetsDisposalGroupMember" abstract="true" name="RoyaltyAssetsDisposalGroupMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_DisposalGroupIncludingDiscontinuedOperationContingentConsiderationValueAddedTaxReceivable" abstract="false" name="DisposalGroupIncludingDiscontinuedOperationContingentConsiderationValueAddedTaxReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pdli_ParadigmSpineMember" abstract="true" name="ParadigmSpineMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="pdli_Deferredissuancecosts" abstract="false" name="Deferredissuancecosts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
