3.26.1 html 154 391 1 false 52 0 false 8 false false R1.htm 0000001 - Document - Cover Sheet http://instilbio.com/role/Cover Cover Cover 1 false false R2.htm 0000002 - Document - Audit Information Sheet http://instilbio.com/role/AuditInformation Audit Information Cover 2 false false R3.htm 9952151 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://instilbio.com/role/CONSOLIDATEDBALANCESHEETS CONSOLIDATED BALANCE SHEETS Statements 3 false false R4.htm 9952152 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://instilbio.com/role/CONSOLIDATEDBALANCESHEETSParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 4 false false R5.htm 9952153 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Sheet http://instilbio.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONSANDCOMPREHENSIVELOSS CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Statements 5 false false R6.htm 9952154 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS??? EQUITY Sheet http://instilbio.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY CONSOLIDATED STATEMENTS OF STOCKHOLDERS??? EQUITY Statements 6 false false R7.htm 9952155 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS??? EQUITY (Parenthetical) Sheet http://instilbio.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical CONSOLIDATED STATEMENTS OF STOCKHOLDERS??? EQUITY (Parenthetical) Statements 7 false false R8.htm 9952156 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://instilbio.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 8 false false R9.htm 9952157 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) Sheet http://instilbio.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSParenthetical CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) Statements 9 false false R10.htm 9952158 - Disclosure - Organization and Description of Business Sheet http://instilbio.com/role/OrganizationandDescriptionofBusiness Organization and Description of Business Notes 10 false false R11.htm 9952159 - Disclosure - Summary of Significant Accounting Policies Sheet http://instilbio.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 11 false false R12.htm 9952160 - Disclosure - Segment Reporting Sheet http://instilbio.com/role/SegmentReporting Segment Reporting Notes 12 false false R13.htm 9952161 - Disclosure - Balance Sheet Components Sheet http://instilbio.com/role/BalanceSheetComponents Balance Sheet Components Notes 13 false false R14.htm 9952162 - Disclosure - Fair Value Measurement Sheet http://instilbio.com/role/FairValueMeasurement Fair Value Measurement Notes 14 false false R15.htm 9952163 - Disclosure - Financial Instruments Sheet http://instilbio.com/role/FinancialInstruments Financial Instruments Notes 15 false false R16.htm 9952164 - Disclosure - License and Collaboration Agreement with ImmuneOnco Sheet http://instilbio.com/role/LicenseandCollaborationAgreementwithImmuneOnco License and Collaboration Agreement with ImmuneOnco Notes 16 false false R17.htm 9952165 - Disclosure - Commitments and Contingencies Sheet http://instilbio.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 17 false false R18.htm 9952166 - Disclosure - Equity Sheet http://instilbio.com/role/Equity Equity Notes 18 false false R19.htm 9952167 - Disclosure - Stock-Based Compensation Sheet http://instilbio.com/role/StockBasedCompensation Stock-Based Compensation Notes 19 false false R20.htm 9952168 - Disclosure - Net Loss Per Share Sheet http://instilbio.com/role/NetLossPerShare Net Loss Per Share Notes 20 false false R21.htm 9952169 - Disclosure - Income Taxes Sheet http://instilbio.com/role/IncomeTaxes Income Taxes Notes 21 false false R22.htm 9952170 - Disclosure - Corporate Restructuring Plan Sheet http://instilbio.com/role/CorporateRestructuringPlan Corporate Restructuring Plan Notes 22 false false R23.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 23 false false R24.htm 995447 - Disclosure - Insider Trading Policies and Procedures Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc Insider Trading Policies and Procedures Notes 24 false false R25.htm 995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure Sheet http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure Cybersecurity Risk Management and Strategy Disclosure Notes 25 false false R26.htm 9955511 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://instilbio.com/role/SummaryofSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://instilbio.com/role/SummaryofSignificantAccountingPolicies 26 false false R27.htm 9955512 - Disclosure - Summary of Significant Accounting Policies (Tables) Sheet http://instilbio.com/role/SummaryofSignificantAccountingPoliciesTables Summary of Significant Accounting Policies (Tables) Tables http://instilbio.com/role/SummaryofSignificantAccountingPolicies 27 false false R28.htm 9955513 - Disclosure - Segment Reporting (Tables) Sheet http://instilbio.com/role/SegmentReportingTables Segment Reporting (Tables) Tables http://instilbio.com/role/SegmentReporting 28 false false R29.htm 9955514 - Disclosure - Balance Sheet Components (Tables) Sheet http://instilbio.com/role/BalanceSheetComponentsTables Balance Sheet Components (Tables) Tables http://instilbio.com/role/BalanceSheetComponents 29 false false R30.htm 9955515 - Disclosure - Fair Value Measurement (Tables) Sheet http://instilbio.com/role/FairValueMeasurementTables Fair Value Measurement (Tables) Tables http://instilbio.com/role/FairValueMeasurement 30 false false R31.htm 9955516 - Disclosure - Financial Instruments (Tables) Sheet http://instilbio.com/role/FinancialInstrumentsTables Financial Instruments (Tables) Tables http://instilbio.com/role/FinancialInstruments 31 false false R32.htm 9955517 - Disclosure - Commitments and Contingencies (Tables) Sheet http://instilbio.com/role/CommitmentsandContingenciesTables Commitments and Contingencies (Tables) Tables http://instilbio.com/role/CommitmentsandContingencies 32 false false R33.htm 9955518 - Disclosure - Stock-Based Compensation (Tables) Sheet http://instilbio.com/role/StockBasedCompensationTables Stock-Based Compensation (Tables) Tables http://instilbio.com/role/StockBasedCompensation 33 false false R34.htm 9955519 - Disclosure - Net Loss Per Share (Tables) Sheet http://instilbio.com/role/NetLossPerShareTables Net Loss Per Share (Tables) Tables http://instilbio.com/role/NetLossPerShare 34 false false R35.htm 9955520 - Disclosure - Income Taxes (Tables) Sheet http://instilbio.com/role/IncomeTaxesTables Income Taxes (Tables) Tables http://instilbio.com/role/IncomeTaxes 35 false false R36.htm 9955521 - Disclosure - Corporate Restructuring Plan (Tables) Sheet http://instilbio.com/role/CorporateRestructuringPlanTables Corporate Restructuring Plan (Tables) Tables http://instilbio.com/role/CorporateRestructuringPlan 36 false false R37.htm 9955522 - Disclosure - Summary of Significant Accounting Policies - Narrative (Details) Sheet http://instilbio.com/role/SummaryofSignificantAccountingPoliciesNarrativeDetails Summary of Significant Accounting Policies - Narrative (Details) Details 37 false false R38.htm 9955523 - Disclosure - Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) Sheet http://instilbio.com/role/SummaryofSignificantAccountingPoliciesScheduleofCashCashEquivalentsandRestrictedCashDetails Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) Details 38 false false R39.htm 9955524 - Disclosure - Summary of Significant Accounting Policies - Schedule of Useful Lives (Details) Sheet http://instilbio.com/role/SummaryofSignificantAccountingPoliciesScheduleofUsefulLivesDetails Summary of Significant Accounting Policies - Schedule of Useful Lives (Details) Details 39 false false R40.htm 9955525 - Disclosure - Segment Reporting - Narrative (Details) Sheet http://instilbio.com/role/SegmentReportingNarrativeDetails Segment Reporting - Narrative (Details) Details 40 false false R41.htm 9955526 - Disclosure - Segment Reporting - Schedule of the Segment Loss, Including Significant Segment Expenses (Details) Sheet http://instilbio.com/role/SegmentReportingScheduleoftheSegmentLossIncludingSignificantSegmentExpensesDetails Segment Reporting - Schedule of the Segment Loss, Including Significant Segment Expenses (Details) Details 41 false false R42.htm 9955527 - Disclosure - Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) Sheet http://instilbio.com/role/BalanceSheetComponentsScheduleofPrepaidExpensesandOtherCurrentAssetsDetails Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) Details 42 false false R43.htm 9955528 - Disclosure - Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) Sheet http://instilbio.com/role/BalanceSheetComponentsScheduleofPropertyPlantandEquipmentNetDetails Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) Details 43 false false R44.htm 9955529 - Disclosure - Balance Sheet Components - Narrative (Details) Sheet http://instilbio.com/role/BalanceSheetComponentsNarrativeDetails Balance Sheet Components - Narrative (Details) Details 44 false false R45.htm 9955530 - Disclosure - Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) Sheet http://instilbio.com/role/BalanceSheetComponentsScheduleofAccruedExpensesandOtherCurrentLiabilitiesDetails Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) Details 45 false false R46.htm 9955531 - Disclosure - Fair Value Measurement - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) Sheet http://instilbio.com/role/FairValueMeasurementScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails Fair Value Measurement - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) Details 46 false false R47.htm 9955532 - Disclosure - Fair Value Measurement - Narrative (Details) Sheet http://instilbio.com/role/FairValueMeasurementNarrativeDetails Fair Value Measurement - Narrative (Details) Details 47 false false R48.htm 9955533 - Disclosure - Fair Value Measurement - Schedule of Level 3 Reconciliation (Details) Sheet http://instilbio.com/role/FairValueMeasurementScheduleofLevel3ReconciliationDetails Fair Value Measurement - Schedule of Level 3 Reconciliation (Details) Details 48 false false R49.htm 9955534 - Disclosure - Financial Instruments - Schedule of Marketable Securities (Details) Sheet http://instilbio.com/role/FinancialInstrumentsScheduleofMarketableSecuritiesDetails Financial Instruments - Schedule of Marketable Securities (Details) Details 49 false false R50.htm 9955535 - Disclosure - Financial Instruments - Narrative (Details) Sheet http://instilbio.com/role/FinancialInstrumentsNarrativeDetails Financial Instruments - Narrative (Details) Details 50 false false R51.htm 9955536 - Disclosure - License and Collaboration Agreement with ImmuneOnco (Details) Sheet http://instilbio.com/role/LicenseandCollaborationAgreementwithImmuneOncoDetails License and Collaboration Agreement with ImmuneOnco (Details) Details http://instilbio.com/role/LicenseandCollaborationAgreementwithImmuneOnco 51 false false R52.htm 9955537 - Disclosure - Commitments and Contingencies - Narrative (Details) Sheet http://instilbio.com/role/CommitmentsandContingenciesNarrativeDetails Commitments and Contingencies - Narrative (Details) Details 52 false false R53.htm 9955538 - Disclosure - Commitments and Contingencies - Schedule of Lease Cost (Details) Sheet http://instilbio.com/role/CommitmentsandContingenciesScheduleofLeaseCostDetails Commitments and Contingencies - Schedule of Lease Cost (Details) Details 53 false false R54.htm 9955539 - Disclosure - Commitments and Contingencies - Schedule of Lease Income Related to the Operating Lease (Details) Sheet http://instilbio.com/role/CommitmentsandContingenciesScheduleofLeaseIncomeRelatedtotheOperatingLeaseDetails Commitments and Contingencies - Schedule of Lease Income Related to the Operating Lease (Details) Details 54 false false R55.htm 9955540 - Disclosure - Commitments and Contingencies - Schedule of Future Fixed Contractual Lease Payments to be Received (Details) Sheet http://instilbio.com/role/CommitmentsandContingenciesScheduleofFutureFixedContractualLeasePaymentstobeReceivedDetails Commitments and Contingencies - Schedule of Future Fixed Contractual Lease Payments to be Received (Details) Details 55 false false R56.htm 9955541 - Disclosure - Commitments and Contingencies - Schedule of Net Carrying Amount of the Liability Component of the Loan (Details) Sheet http://instilbio.com/role/CommitmentsandContingenciesScheduleofNetCarryingAmountoftheLiabilityComponentoftheLoanDetails Commitments and Contingencies - Schedule of Net Carrying Amount of the Liability Component of the Loan (Details) Details 56 false false R57.htm 9955542 - Disclosure - Commitments and Contingencies - Schedule of Interest Expense Related to the Loan (Details) Sheet http://instilbio.com/role/CommitmentsandContingenciesScheduleofInterestExpenseRelatedtotheLoanDetails Commitments and Contingencies - Schedule of Interest Expense Related to the Loan (Details) Details 57 false false R58.htm 9955543 - Disclosure - Equity (Details) Sheet http://instilbio.com/role/EquityDetails Equity (Details) Details http://instilbio.com/role/Equity 58 false false R59.htm 9955544 - Disclosure - Stock-Based Compensation - Narrative (Details) Sheet http://instilbio.com/role/StockBasedCompensationNarrativeDetails Stock-Based Compensation - Narrative (Details) Details 59 false false R60.htm 9955545 - Disclosure - Stock-Based Compensation - Schedule of Option Activity (Details) Sheet http://instilbio.com/role/StockBasedCompensationScheduleofOptionActivityDetails Stock-Based Compensation - Schedule of Option Activity (Details) Details 60 false false R61.htm 9955546 - Disclosure - Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) Sheet http://instilbio.com/role/StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) Details 61 false false R62.htm 9955547 - Disclosure - Stock-Based Compensation - Schedule of Valuation Assumption (Details) Sheet http://instilbio.com/role/StockBasedCompensationScheduleofValuationAssumptionDetails Stock-Based Compensation - Schedule of Valuation Assumption (Details) Details 62 false false R63.htm 9955548 - Disclosure - Net Loss Per Share (Details) Sheet http://instilbio.com/role/NetLossPerShareDetails Net Loss Per Share (Details) Details http://instilbio.com/role/NetLossPerShareTables 63 false false R64.htm 9955549 - Disclosure - Income Taxes - Schedule of Geographical Breakdown of Loss before Provision for Income Taxes (Details) Sheet http://instilbio.com/role/IncomeTaxesScheduleofGeographicalBreakdownofLossbeforeProvisionforIncomeTaxesDetails Income Taxes - Schedule of Geographical Breakdown of Loss before Provision for Income Taxes (Details) Details 64 false false R65.htm 9955550 - Disclosure - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) Sheet http://instilbio.com/role/IncomeTaxesScheduleofEffectiveIncomeTaxRateReconciliationDetails Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) Details 65 false false R66.htm 9955551 - Disclosure - Income Taxes - Schedule of Deferred Income Tax Assets and Liabilities (Details) Sheet http://instilbio.com/role/IncomeTaxesScheduleofDeferredIncomeTaxAssetsandLiabilitiesDetails Income Taxes - Schedule of Deferred Income Tax Assets and Liabilities (Details) Details 66 false false R67.htm 9955552 - Disclosure - Income Taxes - Schedule of Unrecognized Tax Benefits (Details) Sheet http://instilbio.com/role/IncomeTaxesScheduleofUnrecognizedTaxBenefitsDetails Income Taxes - Schedule of Unrecognized Tax Benefits (Details) Details 67 false false R68.htm 9955553 - Disclosure - Income Taxes - Narrative (Details) Sheet http://instilbio.com/role/IncomeTaxesNarrativeDetails Income Taxes - Narrative (Details) Details 68 false false R69.htm 9955554 - Disclosure - Corporate Restructuring Plan - Narrative (Details) Sheet http://instilbio.com/role/CorporateRestructuringPlanNarrativeDetails Corporate Restructuring Plan - Narrative (Details) Details 69 false false R70.htm 9955555 - Disclosure - Corporate Restructuring Plan - Schedule of Restructuring costs by category (Details) Sheet http://instilbio.com/role/CorporateRestructuringPlanScheduleofRestructuringcostsbycategoryDetails Corporate Restructuring Plan - Schedule of Restructuring costs by category (Details) Details 70 false false R71.htm 9955556 - Disclosure - Corporate Restructuring Plan - Schedule of Restructuring Liability (Details) Sheet http://instilbio.com/role/CorporateRestructuringPlanScheduleofRestructuringLiabilityDetails Corporate Restructuring Plan - Schedule of Restructuring Liability (Details) Details 71 false false All Reports Book All Reports til-20251231.htm til-20251231.xsd til-20251231_cal.xml til-20251231_def.xml til-20251231_lab.xml til-20251231_pre.xml http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/cyd/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 true true