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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostsAndExpensesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Costs and Expenses [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostsAndExpensesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating costs and expenses:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenuesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenues [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenuesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EffectiveDateOfWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effective date of warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EffectiveDateOfWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Date of Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EffectiveDateOfWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective date of warrant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalents, and Marketable Securities [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and Investments in Marketable Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Noncash Income (Expense), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Noncash Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNoncashIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Amortization of premiums (discounts), net and other non-cash transactions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification adjustments to income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Hierarchy and NAV</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Adjustments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">OCI, before Reclassifications, Net of Tax, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Milestone</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Milestone [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Milestone [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 2 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 2</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based Compensation Arrangement by Share-based Payment Award [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosureItemAmountsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosureItemAmountsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and Contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Cost [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Restructuring and Related Costs [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreFundedWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Pre Funded Warrant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreFundedWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Pre Funded Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreFundedWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pre-Funded Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaborative Arrangement and Arrangement Other than Collaborative [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchasedDuringPeriodShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Repurchased During Period, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchasedDuringPeriodShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of stock shares repurchased</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockRepurchasedDuringPeriodShares_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Repurchase of common stock from Bristol-Myers Squibb (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfGoodwillTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfGoodwillTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Goodwill [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EliLillyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Eli Lilly.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EliLillyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Eli Lilly [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EliLillyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Eli Lilly</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ReimbursementOfExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reimbursement of expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ReimbursementOfExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reimbursement Of Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ReimbursementOfExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursement of expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Work in Process, Net of Reserves</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryWorkInProcessNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Work-in-process</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UpfrontAndMilestonePaymentsReceivedUnderLicenseAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Upfront and milestone payments received under license agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UpfrontAndMilestonePaymentsReceivedUnderLicenseAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Upfront And Milestone Payments Received Under License Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UpfrontAndMilestonePaymentsReceivedUnderLicenseAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Received upfront and milestone payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventory</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Central Index Key</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Central Index Key</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserveRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Reserve [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserveRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Reserve [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Operating Capital [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in operating assets and liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock shares, issued (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfSharingInDevelopmentCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of sharing in development costs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfSharingInDevelopmentCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Sharing In Development Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfSharingInDevelopmentCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of sharing development costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LitigationReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Estimated Litigation Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LitigationReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liability for litigation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, State or Province</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, State or Province</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Organization and Summary of Significant Accounting Policies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_BristolMyersSquibbCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Bristol-Myers Squibb Company.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_BristolMyersSquibbCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Bristol Myers Squibb Company [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_BristolMyersSquibbCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Bristol Myers Squibb Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Loss before provision for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ContractTerminationAndOtherCostsIncludedInAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract termination and other costs included in accrued expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ContractTerminationAndOtherCostsIncludedInAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract Termination and Other Costs Included in Accrued Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ContractTerminationAndOtherCostsIncludedInAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract termination and other costs included in accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherAccruedLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Accrued Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherAccruedLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseOfLaboratoryAndOfficeSpaceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sublease of Laboratory and Office Space</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseOfLaboratoryAndOfficeSpaceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sublease of laboratory and office space.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PortionAtFairValueFairValueDisclosureMember_lbl" xlink:role="http://fasb.org/us-gaap/role/label/axisDefault">Portion at Fair Value Measurement [Member] [Default]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PortionAtFairValueFairValueDisclosureMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Portion at Fair Value Measurement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PortionAtFairValueFairValueDisclosureMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Portion at Fair Value Measurement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByLiabilityClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liability Class [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByLiabilityClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liability Class [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockCommonShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock, Common, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockCommonShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Treasury Stock, Common, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cover [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cover page.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basic net loss per share (in dollars per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross Unrealized Gains</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated Fair Value at</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OtherPartnerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OtherPartnerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Partner [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OtherPartnerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Partner</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total stock-based compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Retained Earnings (Accumulated Deficit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings (Accumulated Deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TreasuryStockPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Treasury stock policy.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TreasuryStockPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TreasuryStockPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Treasury Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreFundedWarrantTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Pre-funded warrant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreFundedWarrantTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Pre-Funded Warrant [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreFundedWarrantTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pre-Funded Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Operating Activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OperatingLeaseMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Operating Lease, Measurement Input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OperatingLeaseMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Measurement Input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OperatingLeaseMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease, measurement input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PurchaseAndSaleAgreement2020Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase and Sale Agreement 2020</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PurchaseAndSaleAgreement2020Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Purchase and Sale Agreement 2020 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PurchaseAndSaleAgreement2020Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2020 Purchase and Sale Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accumulated Other Comprehensive Income (Loss), Net of Tax, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Other Comprehensive Income (Loss), Net of Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated other comprehensive income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, plant and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property, plant and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Operating Activities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from operating activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfRestructuringDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Type of Restructuring [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfRestructuringDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Type of Restructuring [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringAndRelatedActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring and Related Activities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, par value (in dollars per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LaboratoryEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Laboratory Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LaboratoryEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Laboratory Equipment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LaboratoryEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Laboratory equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MeasurementInputTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MeasurementInputTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MeasurementInputMarketParticipantSubtenantBorrowingRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Measurement Input, Market Participant Subtenant Borrowing Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MeasurementInputMarketParticipantSubtenantBorrowingRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input, Market Participant Subtenant Borrowing Rate [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MeasurementInputMarketParticipantSubtenantBorrowingRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input, Market Participant Subtenant Borrowing Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PropertyPlantAndEquipmentClassifiedToAssetsHeldForSaleMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property Plant And Equipment Classified To Assets Held For Sale</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PropertyPlantAndEquipmentClassifiedToAssetsHeldForSaleMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Classified To Assets Held For Sale Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PropertyPlantAndEquipmentClassifiedToAssetsHeldForSaleMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Property plant and equipment classified to assets held for sale.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Cash Flows [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement of Cash Flows [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_CounterpartyNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Counterparty Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_CounterpartyNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Counterparty Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign currency translation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Foreign Currency Adjustment Attributable to Parent [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities, Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Number of Securities Called by Warrants or Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of warrants issued to be purchase common shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Components [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Components</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Address Line One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Address Line One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Employee-related Liabilities, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee-related Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeSeveranceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee Severance [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeSeveranceMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Severance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total non-operating income (expense), net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringImpairmentAndOtherActivitiesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring, Impairment and Costs of Terminated Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringImpairmentAndOtherActivitiesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring, Impairment, and Other Activities Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Flag</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Amendment Flag</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CorporateDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Corporate Debt Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CorporateDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate notes and bonds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Finished Goods, Net of Reserves</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryFinishedGoodsNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finished goods</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid in Capital, Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capital in excess of par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringPlanDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Plan [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringPlanDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Plan [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock, Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Research and development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ManufacturingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Huntsville, Alabama Manufacturing Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ManufacturingFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Manufacturing Facility [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Component [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Component</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Name of Property [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Name of Property [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Organization and summary of significant accounting policies.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization And Summary Of Significant Accounting Policies [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Organization And Summary Of Significant Accounting Policies [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">General and Administrative Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">General and Administrative Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Nonoperating Income (Expense), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other income (expense), net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Furniture and Fixtures [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Furniture, fixtures and other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockCommonMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock, Common [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockCommonMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Treasury Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TcgCrossoverFundIILPMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">TCG Crossover Fund II, L.P.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TcgCrossoverFundIILPMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">TCG Crossover Fund I I, L P [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TcgCrossoverFundIILPMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">TCG Crossover Fund II, L.P.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Other Current Assets [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Other Current Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProvisionForInventoryObsolescence_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Provision for inventory obsolescence</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProvisionForInventoryObsolescence_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Provision For Inventory Obsolescence</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProvisionForInventoryObsolescence_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Provision for inventory obsolescence.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProvisionForInventoryObsolescence_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Provision for net realizable value of inventory</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Derivative Liabilities at Fair Value [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Derivative Liabilities at Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, Credit Loss Expense (Reversal)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts receivable, credit loss expense (reversal)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ContractTerminationAndOtherCostsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract Termination and Other Costs [Member[</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ContractTerminationAndOtherCostsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract Termination and Other Costs [Member[</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ContractTerminationAndOtherCostsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract Termination and Other Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LifeSciencesLeaseMarketMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Life Sciences Lease Market</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LifeSciencesLeaseMarketMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Life Sciences Lease Market [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LifeSciencesLeaseMarketMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Life sciences lease market.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaborative Arrangement and Arrangement Other than Collaborative [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeveranceCosts1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Severance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeveranceCosts1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Severance and benefit expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other comprehensive income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">License and Collaboration Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromAmendmentRelatedToSalesOfFutureRoyaltiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from Amendment related to sales of future royalties, net.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromAmendmentRelatedToSalesOfFutureRoyaltiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Amendment related to sales of future royalties, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromAmendmentRelatedToSalesOfFutureRoyaltiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from the Amendment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Comprehensive Income (Loss), Net of Tax, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Comprehensive income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Comprehensive loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares outstanding (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleasePropertyPlantAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sublease Property, Plant And Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleasePropertyPlantAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sublease Property, Plant And Equipment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleasePropertyPlantAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Debt Securities, Available-for-Sale</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, par value (in dollars per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maturities of investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_IncreaseDecreaseInOperatingLeaseRightOfUseAssetsNetOfOperatingLeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase (Decrease) In Operating Lease Right-Of-Use Assets, Net Of Operating Lease Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_IncreaseDecreaseInOperatingLeaseRightOfUseAssetsNetOfOperatingLeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) In Operating Lease Right-Of-Use Assets, Net Of Operating Lease Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_IncreaseDecreaseInOperatingLeaseRightOfUseAssetsNetOfOperatingLeaseLiabilities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Operating leases, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseIncomeMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sublease Income, Measurement Input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseIncomeMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sublease Income, Measurement Input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseIncomeMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sublease income, measurement input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReorganizationValueNetRealizableValueOfAssetDispositions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reorganization Value, Net Realizable Value of Asset Dispositions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReorganizationValueNetRealizableValueOfAssetDispositions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net realizable value of assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UcbPharmaManufacturingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">UCB Pharma Manufacturing Agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UcbPharmaManufacturingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">UCB Pharma Manufacturing Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UcbPharmaManufacturingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">UCB Pharma Manufacturing Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Cash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Cash_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ImpairmentOfRemainingLongLivedAssetHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Impairment of remaining long-lived asset, held-for-use.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ImpairmentOfRemainingLongLivedAssetHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment of Remaining Long-Lived Asset, Held-for-Use</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ImpairmentOfRemainingLongLivedAssetHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional impairment charges on remaining long-lived assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Interactive Data Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Interactive Data Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProductMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product sales</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfSalesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Sales [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfSalesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of goods sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashInterestExpenseRelatedToSaleOfRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-cash interest expense related to sale of royalties.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashInterestExpenseRelatedToSaleOfRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Cash Interest Expense Related To Sale Of Royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashInterestExpenseRelatedToSaleOfRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashInterestExpenseRelatedToSaleOfRoyalties_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Non-cash interest expense on liabilities related to the sales of future royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashInterestExpenseRelatedToSaleOfRoyalties_lbl" xlink:role="http://www.xbrl.org/2009/role/netLabel">Non-cash interest expense on liabilities related to the sales of future royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentQuarterlyReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Quarterly Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentQuarterlyReport_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Quarterly Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidatedEntitiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidated Entities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidatedEntitiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidated Entities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Cash and cash equivalents at end of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Cash and cash equivalents at beginning of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Financial Position Location, Balance [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cost of Goods and Services Sold, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Goods and Services Sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of goods sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_BristolMyersSquibbCollaborationAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Bristol Myers Squibb collaboration agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_BristolMyersSquibbCollaborationAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Bristol Myers Squibb Collaboration Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_BristolMyersSquibbCollaborationAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Bristol Myers Squibb Collaboration Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related and Nonrelated Parties [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ParentCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Parent Company [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ParentCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nektar's</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Financial Instruments, Liabilities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Development Derivative Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommercialPaperMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commercial Paper [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommercialPaperMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate commercial paper</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effect of foreign exchange rates on cash and cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ThirdStFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Third St. Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ThirdStFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Third St. Facility [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ThirdStFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Third St. Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByMeasurementBasisAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Basis [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByMeasurementBasisAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Basis [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Location [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostAndReserveAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostAndReserveAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TwoThousandTwentyTwoRestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Twenty Two Restructuring Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TwoThousandTwentyTwoRestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Two Restructuring Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TwoThousandTwentyTwoRestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022 Restructuring Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds From Sale of Future Royalties.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sale of Future Royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of future royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UpfrontAndMilestonePaymentsReceivedFromLicenseAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Upfront and milestone payments received from license agreements.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UpfrontAndMilestonePaymentsReceivedFromLicenseAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Upfront And Milestone Payments Received From License Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_UpfrontAndMilestonePaymentsReceivedFromLicenseAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Upfront and milestone payments received from license agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SecuritiesPurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Securities Purchase Agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SecuritiesPurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Securities Purchase Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SecuritiesPurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Securities Purchase Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Milestone [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Milestone [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Milestone [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, City or Town</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, City or Town</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Accumulated Other Comprehensive Income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">AOCI Attributable to Parent [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Other Comprehensive Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CollaborativeArrangementSuccessBasedPaymentsAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaborative Arrangement, Success-Based Payments, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CollaborativeArrangementSuccessBasedPaymentsAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement, Success-Based Payments, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CollaborativeArrangementSuccessBasedPaymentsAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Success payments (up to)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AggregateCommonSharesIssuedToPurchasePrefundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Aggregate common shares issued to purchase prefunded warrants.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AggregateCommonSharesIssuedToPurchasePrefundedWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Aggregate common shares issued to purchase prefunded warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForRestructuring_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments for Restructuring</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForRestructuring_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments during the period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForRestructuring_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Payments during the period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostAndReserveLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Cost and Reserve [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostAndReserveLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Cost and Reserve [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-Based Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate number of shares authorized (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued under equity compensation plans (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreferredStockShareDesignated_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Preferred stock, shares designated.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreferredStockShareDesignated_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock Share Designated</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PreferredStockShareDesignated_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares designated (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Disclosures [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CashRestrictedCashCashEquivalentsAndAvailableForSaleInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash, restricted cash, cash equivalents, and available for sale investments.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CashRestrictedCashCashEquivalentsAndAvailableForSaleInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Restricted Cash Cash Equivalents And Available For Sale Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CashRestrictedCashCashEquivalentsAndAvailableForSaleInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and investments in marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CashRestrictedCashCashEquivalentsAndAvailableForSaleInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total cash and investments in marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CollaborativeArrangementCommittedFunding_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaborative Arrangement, Committed Funding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CollaborativeArrangementCommittedFunding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement, Committed Funding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_CollaborativeArrangementCommittedFunding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Committed funding (up to)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_StockOptionsRSUsAndPSUsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock Options, RSUs And PSUs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_StockOptionsRSUsAndPSUsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Options, RSUs And PSUs [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_StockOptionsRSUsAndPSUsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock Options, RSUs And PSUs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Type</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Document Type</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USGovernmentAgenciesDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">US Government Agencies Debt Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USGovernmentAgenciesDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Obligations of U.S. government agencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Title of 12(b) Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of 12(b) Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash and Cash Equivalents, at Carrying Value, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents, at Carrying Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PropertyPlantAndEquipmentAndOperatingLeaseRightOfUseAssetFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Property, Plant And Equipment, And Operating Lease Right Of Use Asset, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PropertyPlantAndEquipmentAndOperatingLeaseRightOfUseAssetFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant And Equipment, And Operating Lease Right Of Use Asset, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PropertyPlantAndEquipmentAndOperatingLeaseRightOfUseAssetFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, plant and equipment and operating lease right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Financial Position Location, Balance [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Stockholders' Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement of Stockholders' Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Fair value at end of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Fair value at beginning of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Period Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Period Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in the fair value of development derivative liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Research and Development Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Class [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Asset Class [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basis of Presentation and Principles of Consolidation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfSharingInPhaseTwoDevelopmentCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of sharing in Phase 2 development costs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfSharingInPhaseTwoDevelopmentCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Sharing In Phase Two Development Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfSharingInPhaseTwoDevelopmentCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of sharing in Phase 2 development costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedClinicalTrialExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued clinical trial expenses current.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedClinicalTrialExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Clinical Trial Expenses Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedClinicalTrialExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued clinical trial expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PurchaseAndSaleAgreement2012Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase and Sale Agreement 2012</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PurchaseAndSaleAgreement2012Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Purchase and Sale Agreement 2012 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PurchaseAndSaleAgreement2012Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2012 Purchase and Sale Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ResaleOfCommonStockIssuableUponExerciseOfWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Resale of common stock issuable upon exercise of warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ResaleOfCommonStockIssuableUponExerciseOfWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Resale of Common Stock Issuable Upon Exercise of Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ResaleOfCommonStockIssuableUponExerciseOfWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Resale of common stock issuable upon exercise of warrant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MissionBayFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Mission Bay Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MissionBayFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Mission Bay Facility [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MissionBayFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Mission Bay Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EstimateOfFairValueFairValueDisclosureMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Estimate of Fair Value Measurement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EstimateOfFairValueFairValueDisclosureMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimate of Fair Value Measurement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LiabilitiesOnSaleOfFutureRoyaltiesAmortizedTransactionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Liabilities On Sale Of Future Royalties Amortized Transaction Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LiabilitiesOnSaleOfFutureRoyaltiesAmortizedTransactionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities On Sale Of Future Royalties Amortized Transaction Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LiabilitiesOnSaleOfFutureRoyaltiesAmortizedTransactionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of transaction costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Depreciable Property, plant and equipment, Gross.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciable Property Plant And Equipment Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciable property, plant and equipment at cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Exercise Price of Warrants or Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise price of warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instruments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial Instruments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Investing Activities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from investing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Date from which Warrants or Rights Exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments for Repurchase of Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Repurchase of common stock from Bristol-Myers Squibb</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetImpairmentChargesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Impairment Charges [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetImpairmentChargesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer, Excluding Assessed Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue, excluding assessed tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Comprehensive Income [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement of Comprehensive Income [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PotentialDevelopmentAndRegulatoryMilestones_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Potential development and regulatory milestones.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PotentialDevelopmentAndRegulatoryMilestones_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Potential Development And Regulatory Milestones</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PotentialDevelopmentAndRegulatoryMilestones_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Potential future additional development and regulatory milestones (up to)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Costs Associated with Exit or Disposal Activities or Restructurings, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidatedEntitiesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidated Entities [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidatedEntitiesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidated Entities [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Stockholders' Equity [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increase (Decrease) in Stockholders' Equity [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Depreciation, Depletion and Amortization, Nonproduction, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation, Depletion and Amortization, Nonproduction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation and amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Accrued Liabilities, Current</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Accounts Payable, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">LIABILITIES AND STOCKHOLDERS&#8217; EQUITY</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_Nektar358Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Nektar-358</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_Nektar358Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nektar-358 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_Nektar358Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nektar-358</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Period End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Period End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Financing Activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash provided by financing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_Nektar214Member_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Nektar 214.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_Nektar214Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nektar 214 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_Nektar214Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nektar 214</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SharePurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share purchase agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SharePurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Purchase Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SharePurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Potentially dilutive securities (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CarryingReportedAmountFairValueDisclosureMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reported Value Measurement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CarryingReportedAmountFairValueDisclosureMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reported Value Measurement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restructuring Reserve, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Reserve</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Restructuring reserve, beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Restructuring reserve, ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Restructuring plan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Provision (benefit) for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Income Tax Expense (Benefit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Benefit for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trading Symbol</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trading Symbol</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total stockholders&#8217; equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostsAndAssetImpairmentCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Costs and Asset Impairment Charges</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostsAndAssetImpairmentCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring, impairment and costs of terminated program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringCostsAndAssetImpairmentCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restructuring, impairment and other costs of terminated program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Lived Tangible Asset [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other long-term liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash receipts from SFJ</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Stock-Based Compensation Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LicenseAndCollaborationAgreementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">License and collaboration agreements.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LicenseAndCollaborationAgreementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">License And Collaboration Agreements [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LicenseAndCollaborationAgreementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Milestone One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Milestone One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_MilestoneOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Milestone One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MeasurementInputTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Input Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MeasurementInputTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Measurement Input Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Income Tax Expense (Benefit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred income tax expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross unrealized losses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Gross Unrealized Losses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring and Related Costs [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Restructuring, Impairment and Other Costs of Terminated Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_AffiliatedEntityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Affiliated Entity [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_AffiliatedEntityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Affiliates</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Use of Estimates, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Use of Estimates</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseOperatingLeaseRightOfUseAssetsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sublease Operating Lease Right of Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseOperatingLeaseRightOfUseAssetsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sublease Operating Lease Right of Use Assets [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SubleaseOperatingLeaseRightOfUseAssetsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Lease Right-of-Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RoyaltiesLiabilityMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Royalties Liability, Measurement Input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RoyaltiesLiabilityMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Royalties Liability, Measurement Input</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RoyaltiesLiabilityMeasurementInput_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Royalties liability discount rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Security Exchange Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Security Exchange Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Counterparty Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Counterparty Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LicenseCollaborationAndOtherRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">License collaboration and other revenue.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LicenseCollaborationAndOtherRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">License Collaboration And Other Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LicenseCollaborationAndOtherRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">License, collaboration and other revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_WarrantExercisedPriorNoticePeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant exercised prior notice period.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_WarrantExercisedPriorNoticePeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Exercised Prior Notice Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_WarrantExercisedPriorNoticePeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant exercised prior notice period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value by Liability Class [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value by Liability Class [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Lived Tangible Asset [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Less: accumulated depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LegalEntityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Legal Entity [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LegalEntityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Legal Entity [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Organization and summary of significant accounting policies.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization And Summary Of Significant Accounting Policies [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Organization And Summary Of Significant Accounting Policies [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Arrangement, Contract to Perform for Others, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development Arrangement, Contract to Perform for Others, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities and stockholders&#8217; equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring and Related Cost, Number of Positions Eliminated, Period Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Workforce termination, percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Right-of-Use Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ComputerFurnitureAndOtherMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Furniture computer and other.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ComputerFurnitureAndOtherMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Computer Furniture And Other [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ComputerFurnitureAndOtherMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Computer equipment and computer software</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Diluted, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Diluted net loss per share (in dollars per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_InterestAndOtherNonTradeReceivablesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest and Other Non-trade Receivables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_InterestAndOtherNonTradeReceivablesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest and Other Non-trade Receivables [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_InterestAndOtherNonTradeReceivablesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest and other non-trade receivables.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Hierarchy and NAV</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided by (Used in) Investing Activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash provided by investing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EliLillyAndCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Eli Lilly and Company.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EliLillyAndCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Eli Lilly And Company [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_EliLillyAndCompanyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Eli Lilly And Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PrepaidResearchAndDevelopmentExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prepaid Research And Development Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PrepaidResearchAndDevelopmentExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Research And Development Expenses [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PrepaidResearchAndDevelopmentExpensesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid research and development expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedResearchAndDevelopmentExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued research and development expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedResearchAndDevelopmentExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Research And Development Expenses Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedResearchAndDevelopmentExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued research and development expenses current.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Filer Category</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Filer Category</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense) [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-operating income (expense):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Fiscal Year End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current Fiscal Year End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ImpairmentLongLivedAssetHeldForUseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Impairment, Long-Lived Asset, Held-for-Use, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ImpairmentLongLivedAssetHeldForUseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment, Long-Lived Asset, Held-for-Use, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ImpairmentLongLivedAssetHeldForUseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of other property, plant and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related and Nonrelated Parties [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Registrant Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Registrant Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SFJPharmaceuticalsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">SFJ Pharmaceuticals</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SFJPharmaceuticalsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SFJ Pharmaceuticals [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SFJPharmaceuticalsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SFJ</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Emerging Growth Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Emerging Growth Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Money Market Funds [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Money market funds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted Average Number of Shares Outstanding, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average shares outstanding used in computing basic net loss per share (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ScheduleOfLiabilityRelatedToSaleOfPotentialFutureRoyaltiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule Of Liability Related To Sale Of Potential Future Royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ScheduleOfLiabilityRelatedToSaleOfPotentialFutureRoyaltiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Liability Related To Sale Of Potential Future Royalties [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ScheduleOfLiabilityRelatedToSaleOfPotentialFutureRoyaltiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Liability Related to Sale of Potential Future Royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares authorized (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross proceeds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 1 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 1</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Excluding Option Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from shares issued under equity compensation plans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financial Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Loss per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Available-for-sale securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyaltiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-cash royalty revenue related to sale of future royalties.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyaltiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Cash Royalty Revenue Related To Sale Of Future Royalties [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyaltiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash royalty revenue related to the sales of future royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyaltiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Non-cash royalty revenue related to the sales of future royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">General and Administrative Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Total impairment of right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment, Long-Lived Asset, Held-for-Use</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of other property, plant and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Impairment of right-of-use assets and property, plant and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total impairment of right-of-use assets and property, plant and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedContractTerminationCostsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued Contract Termination Costs, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedContractTerminationCostsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Contract Termination Costs, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_AccruedContractTerminationCostsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued contract termination costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disclosure of Compensation Related Costs, Share-based Payments [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Asset Impairment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued under equity compensation plans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of pre-funded warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill, Impairment Loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Impairment of goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Impairment of goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Accumulated Other Comprehensive Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringPlanAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring Plan [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestructuringPlanAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Plan [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Debt Securities, Available-for-Sale, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Raw Materials, Net of Reserves</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryRawMaterialsNetOfReserves_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Raw materials</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders&#8217; equity:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrentNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Liability related to sale of potential future royalties non current net of issuance costs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrentNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liability Related To Sale Of Potential Future Royalties Non Current Net Of Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrentNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities related to the sales of future royalties, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Property, Plant and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_FinancingTransactionsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Financing transactions policy.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_FinancingTransactionsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financing Transactions [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_FinancingTransactionsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financing Transactions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares authorized (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity File Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity File Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net increase (decrease) in cash and cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SaleOfStockConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sale of stock consideration received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SaleOfStockConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale Of Stock Consideration Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_SaleOfStockConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of stock consideration received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventory Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Financial Position [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement of Financial Position [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued, price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityShellCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Shell Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityShellCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Shell Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Tax Identification Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Tax Identification Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ASSETS</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Construction in Progress, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction in process</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Current Reporting Status</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Current Reporting Status</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Condensed Consolidated Financial Statement Details</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Year Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Year Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Costs Associated with Exit or Disposal Activity or Restructuring [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring Plans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CertificatesOfDepositMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Certificates of Deposit [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CertificatesOfDepositMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Certificates of deposit</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock, Value, Acquired, Cost Method</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Repurchase of common stock from Bristol-Myers Squibb</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">City Area Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueAdjustment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Fair Value Adjustment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueAdjustment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of development derivative liability</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total inventory, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Inventory, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InventoryNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventory, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Local Phone Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Total impairment of lease assets</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseImpairmentLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Impairment charge for right-of-use asset</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Preferred Stock, Shares Outstanding, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Preferred Stock, Shares Outstanding, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares outstanding (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessExitCosts1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Exit Costs</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TwoThousandTwentyThreeRestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Three Restructuring Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TwoThousandTwentyThreeRestructuringPlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023 Restructuring Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiary, Sale of Stock [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and Contingencies Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockValue_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Treasury stock, at cost; 8,285 shares as of June 30, 2024 and none as of December 31, 2023, respectively</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Treasury Stock, Value, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock, Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TreasuryStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Treasury stock, at cost; 8,285 shares as of March 31, 2024 and and none as of December 31, 2023, respectively</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromSaleOfPotentialFutureRoyaltiesGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of royalty rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromSaleOfPotentialFutureRoyaltiesGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sale Of Potential Future Royalties Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_ProceedsFromSaleOfPotentialFutureRoyaltiesGross_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from sale of potential future royalties gross.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Amortized Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Amortized Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsAchieved_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payment of transaction related to purchase and sale agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsAchieved_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payment of Transaction Related to Purchase and Sale Agreement if Threshold is Achieved</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsAchieved_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payment of Transaction Related to Purchase and Sale Agreement if Threshold is Achieved</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OpdivoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Opdivo.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OpdivoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Opdivo [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OpdivoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Opdivo</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities, current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net foreign currency translation gain (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expenses and Other Current Assets [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other prepaid expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Payments to Acquire Property, Plant, and Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of property, plant and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Transition Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Transition Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Other Operating Assets, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Operating Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk, Credit Risk, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Significant Concentrations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfNumberOfSharesForWarrantExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of number of shares of warrant exercised.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfNumberOfSharesForWarrantExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage of Number of Shares for Warrant Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PercentageOfNumberOfSharesForWarrantExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of number of shares of warrant exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid-in Capital [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capital in Excess of Par Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Adjustments to reconcile net loss to net cash used in operating activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other comprehensive income (loss):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Location [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Depreciable Property, plant and equipment, Net.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciable Property Plant And Equipment Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Depreciable property, plant and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RestructuringImpairmentAndOtherCostsOfTerminatedProgramMemberMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Restructuring, Impairment And Other Costs Of Terminated Program Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RestructuringImpairmentAndOtherCostsOfTerminatedProgramMemberMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restructuring, Impairment And Other Costs Of Terminated Program Member [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_RestructuringImpairmentAndOtherCostsOfTerminatedProgramMemberMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restructuring, impairment and other costs of terminated program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsNotAchieved_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payment of transaction related to purchase and sale agreement if threshold is not achieved</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsNotAchieved_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payment of Transaction Related to Purchase and Sale Agreement if Threshold is not Achieved</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsNotAchieved_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payment of Transaction Related to Purchase and Sale Agreement if Threshold is not Achieved</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Inventory, Current [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfInventoryCurrentTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Inventory</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non cash royalty revenue related to sale future royalties.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Cash Royalty Revenue Related To Sale Of Future Royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Non-cash royalty revenue related to the sales of future royalties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyalties_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Non-cash royalty revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill and Intangible Assets Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Common Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PotentialDevelopmentMilestones_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Potential development milestones.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_PotentialDevelopmentMilestones_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Potential Development Milestones</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Name of Property [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Name of Property [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentIncomeInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment Income, Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentIncomeInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_TwoThousandSeventeenPerformanceIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Seventeen Performance Incentive Plan</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Arrangement, Contract to Perform for Others, Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development Arrangement, Contract to Perform for Others, Type [Axis]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="nktr_OrganizationPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Organization.</link:label>
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          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionInProgressGross" xlink:label="us-gaap_ConstructionInProgressGross"/>
          <link:loc xlink:type="locator" xlink:href="nktr-20240630.xsd#nktr_DepreciablePropertyPlantAndEquipmentNet" xlink:label="nktr_DepreciablePropertyPlantAndEquipmentNet"/>
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        <link:calculationLink xlink:type="extended" xlink:role="http://www.nektar.com/20240630/taxonomy/role/CondensedConsolidatedFinancialStatementDetailsScheduleofAccruedExpensesDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="nktr_LiabilityToCollaborationPartnersCurrent" order="0" weight="1.0" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="nktr_AccruedClinicalTrialExpensesCurrent" order="1" weight="1.0" use="optional"/>
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          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent" order="5" weight="1.0" use="optional"/>
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          <link:loc xlink:type="locator" xlink:href="nktr-20240630.xsd#nktr_AccruedClinicalTrialExpensesCurrent" xlink:label="nktr_AccruedClinicalTrialExpensesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="nktr-20240630.xsd#nktr_AccruedResearchAndDevelopmentExpensesCurrent" xlink:label="nktr_AccruedResearchAndDevelopmentExpensesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
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        <link:calculationLink xlink:type="extended" xlink:role="http://www.nektar.com/20240630/taxonomy/role/DisclosureRestructuringImpairmentAndCostsOfTerminatedProgramSummaryOfRestructuringCostsDetails">
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          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeveranceCosts1" xlink:label="us-gaap_SeveranceCosts1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessExitCosts1" xlink:label="us-gaap_BusinessExitCosts1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossOnContractTermination" xlink:label="us-gaap_LossOnContractTermination"/>
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        <link:calculationLink xlink:type="extended" xlink:role="http://www.nektar.com/20240630/taxonomy/role/DisclosureRestructuringImpairmentAndCostsOfTerminatedProgramSubleaseInformationDetails">
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  </xsd:annotation>
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  <xsd:element id="nktr_StockOptionsRSUsAndPSUsMember" name="StockOptionsRSUsAndPSUsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_AccruedResearchAndDevelopmentExpensesCurrent" name="AccruedResearchAndDevelopmentExpensesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_IncreaseDecreaseInOperatingLeaseRightOfUseAssetsNetOfOperatingLeaseLiabilities" name="IncreaseDecreaseInOperatingLeaseRightOfUseAssetsNetOfOperatingLeaseLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_InterestAndOtherNonTradeReceivablesMember" name="InterestAndOtherNonTradeReceivablesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_AccruedClinicalTrialExpensesCurrent" name="AccruedClinicalTrialExpensesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_SharePurchaseAgreementMember" name="SharePurchaseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_SubleaseOperatingLeaseRightOfUseAssetsMember" name="SubleaseOperatingLeaseRightOfUseAssetsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ReimbursementOfExpenses" name="ReimbursementOfExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_UcbPharmaManufacturingAgreementMember" name="UcbPharmaManufacturingAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_TreasuryStockPolicyTextBlock" name="TreasuryStockPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_LicenseAndCollaborationAgreementsAbstract" name="LicenseAndCollaborationAgreementsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_AccruedContractTerminationCostsCurrent" name="AccruedContractTerminationCostsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_Nektar214Member" name="Nektar214Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ResaleOfCommonStockIssuableUponExerciseOfWarrant" name="ResaleOfCommonStockIssuableUponExerciseOfWarrant" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_PercentageOfSharingInPhaseTwoDevelopmentCosts" name="PercentageOfSharingInPhaseTwoDevelopmentCosts" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_PercentageOfSharingInDevelopmentCosts" name="PercentageOfSharingInDevelopmentCosts" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_ComputerFurnitureAndOtherMember" name="ComputerFurnitureAndOtherMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_AmountExchangedToRemoveCapOnRoyalties" name="AmountExchangedToRemoveCapOnRoyalties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_LicenseCollaborationAndOtherRevenueMember" name="LicenseCollaborationAndOtherRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_TwoThousandTwentyThreeRestructuringPlanMember" name="TwoThousandTwentyThreeRestructuringPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ImpairmentLongLivedAssetHeldForUseOther" name="ImpairmentLongLivedAssetHeldForUseOther" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_MeasurementInputMarketParticipantSubtenantBorrowingRateMember" name="MeasurementInputMarketParticipantSubtenantBorrowingRateMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_UpfrontAndMilestonePaymentsReceivedUnderLicenseAgreement" name="UpfrontAndMilestonePaymentsReceivedUnderLicenseAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_UpfrontAndMilestonePaymentsReceivedFromLicenseAgreements" name="UpfrontAndMilestonePaymentsReceivedFromLicenseAgreements" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_SubleaseOfLaboratoryAndOfficeSpaceMember" name="SubleaseOfLaboratoryAndOfficeSpaceMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_SecuritiesPurchaseAgreementMember" name="SecuritiesPurchaseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyalties" name="NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyalties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_OpdivoMember" name="OpdivoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrentNetOfIssuanceCosts" name="LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrentNetOfIssuanceCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_PotentialDevelopmentMilestones" name="PotentialDevelopmentMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_MissionBayFacilityMember" name="MissionBayFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_EliLillyMember" name="EliLillyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ThirdStFacilityMember" name="ThirdStFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_SaleOfStockConsiderationReceived" name="SaleOfStockConsiderationReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_DepreciablePropertyPlantAndEquipmentGross" name="DepreciablePropertyPlantAndEquipmentGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsAchieved" name="PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsAchieved" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_MilestoneOneMember" name="MilestoneOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_CollaborativeArrangementSuccessBasedPaymentsAmount" name="CollaborativeArrangementSuccessBasedPaymentsAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_PreFundedWarrantTextBlock" name="PreFundedWarrantTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_Nektar358Member" name="Nektar358Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrent" name="LiabilityRelatedToSaleOfPotentialFutureRoyaltiesNonCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyaltiesMember" name="NonCashRoyaltyRevenueRelatedToSaleOfFutureRoyaltiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_TcgCrossoverFundIILPMember" name="TcgCrossoverFundIILPMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ProceedsFromAmendmentRelatedToSalesOfFutureRoyaltiesNet" name="ProceedsFromAmendmentRelatedToSalesOfFutureRoyaltiesNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_PropertyPlantAndEquipmentClassifiedToAssetsHeldForSaleMember" name="PropertyPlantAndEquipmentClassifiedToAssetsHeldForSaleMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ProvisionForInventoryObsolescence" name="ProvisionForInventoryObsolescence" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_ImpairmentOfRemainingLongLivedAssetHeldForUse" name="ImpairmentOfRemainingLongLivedAssetHeldForUse" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_ManufacturingLaboratoryAndOtherEquipmentMember" name="ManufacturingLaboratoryAndOtherEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_SaleOfStockRepurchasedCashConsideration" name="SaleOfStockRepurchasedCashConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_OperatingLeaseMeasurementInput" name="OperatingLeaseMeasurementInput" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_AggregateCommonSharesIssuedToPurchasePrefundedWarrants" name="AggregateCommonSharesIssuedToPurchasePrefundedWarrants" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_LiabilitiesOnSaleOfFutureRoyaltiesAmortizedTransactionCosts" name="LiabilitiesOnSaleOfFutureRoyaltiesAmortizedTransactionCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_ProceedsFromSaleOfPotentialFutureRoyaltiesGross" name="ProceedsFromSaleOfPotentialFutureRoyaltiesGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_BristolMyersSquibbCompanyMember" name="BristolMyersSquibbCompanyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsNotAchieved" name="PaymentOfTransactionRelatedToPurchaseAndSaleAgreementIfThresholdIsNotAchieved" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_SubleasePropertyPlantAndEquipmentMember" name="SubleasePropertyPlantAndEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_CashRestrictedCashCashEquivalentsAndAvailableForSaleInvestments" name="CashRestrictedCashCashEquivalentsAndAvailableForSaleInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_CollaborativeArrangementCommittedFunding" name="CollaborativeArrangementCommittedFunding" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_SFJPharmaceuticalsMember" name="SFJPharmaceuticalsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_NonCashInterestExpenseRelatedToSaleOfRoyalties" name="NonCashInterestExpenseRelatedToSaleOfRoyalties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_TwoThousandTwentyTwoRestructuringPlanMember" name="TwoThousandTwentyTwoRestructuringPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PreferredStockShareDesignated" name="PreferredStockShareDesignated" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="nktr_ScheduleOfLiabilityRelatedToSaleOfPotentialFutureRoyaltiesTableTextBlock" name="ScheduleOfLiabilityRelatedToSaleOfPotentialFutureRoyaltiesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_DepreciablePropertyPlantAndEquipmentNet" name="DepreciablePropertyPlantAndEquipmentNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_RestructuringImpairmentAndOtherCostsOfTerminatedProgramMemberMember" name="RestructuringImpairmentAndOtherCostsOfTerminatedProgramMemberMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_RestructuringPlanMember" name="RestructuringPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PurchaseAndSaleAgreement2020Member" name="PurchaseAndSaleAgreement2020Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems" name="OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_LaboratoryEquipmentMember" name="LaboratoryEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PropertyPlantAndEquipmentAndOperatingLeaseRightOfUseAssetFairValueDisclosure" name="PropertyPlantAndEquipmentAndOperatingLeaseRightOfUseAssetFairValueDisclosure" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_EffectiveDateOfWarrant" name="EffectiveDateOfWarrant" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_SubleaseIncomeMeasurementInput" name="SubleaseIncomeMeasurementInput" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_ContractTerminationAndOtherCostsMember" name="ContractTerminationAndOtherCostsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PercentageOfSharingInProductionCosts" name="PercentageOfSharingInProductionCosts" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_PrepaidResearchAndDevelopmentExpensesMember" name="PrepaidResearchAndDevelopmentExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_EliLillyAndCompanyMember" name="EliLillyAndCompanyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_BuildingAndLeaseholdImprovementsMember" name="BuildingAndLeaseholdImprovementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_BristolMyersSquibbCollaborationAgreementMember" name="BristolMyersSquibbCollaborationAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_MilestoneAxis" name="MilestoneAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PreFundedWarrantMember" name="PreFundedWarrantMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_MilestoneDomain" name="MilestoneDomain" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_ContractTerminationAndOtherCostsIncludedInAccruedExpenses" name="ContractTerminationAndOtherCostsIncludedInAccruedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_ProceedsFromSaleOfFutureRoyalties" name="ProceedsFromSaleOfFutureRoyalties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_TwoThousandSeventeenPerformanceIncentivePlanMember" name="TwoThousandSeventeenPerformanceIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_OrganizationPolicyTextBlock" name="OrganizationPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_LifeSciencesLeaseMarketMember" name="LifeSciencesLeaseMarketMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_PotentialDevelopmentAndRegulatoryMilestones" name="PotentialDevelopmentAndRegulatoryMilestones" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_OtherPartnerMember" name="OtherPartnerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityResearchAndDevelopmentExpense" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityResearchAndDevelopmentExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_LiabilityToCollaborationPartnersCurrent" name="LiabilityToCollaborationPartnersCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="nktr_PurchaseAndSaleAgreement2012Member" name="PurchaseAndSaleAgreement2012Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_IssuanceOfPrefundedWarrant" name="IssuanceOfPrefundedWarrant" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="nktr_PercentageOfNumberOfSharesForWarrantExercised" name="PercentageOfNumberOfSharesForWarrantExercised" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_OrganizationAndSummaryOfSignificantAccountingPoliciesTable" name="OrganizationAndSummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="nktr_FinancingTransactionsPolicyTextBlock" name="FinancingTransactionsPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="nktr_RoyaltiesLiabilityMeasurementInput" name="RoyaltiesLiabilityMeasurementInput" type="xbrli:decimalItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
</xsd:schema>
