3.26.1 html 269 336 1 false 82 0 false 9 false false R1.htm 0000001 - Document - Cover Page Sheet http://www.cartesiantherapeutics.com/role/CoverPage Cover Page Cover 1 false false R2.htm 9952151 - Statement - Consolidated Balance Sheets Sheet http://www.cartesiantherapeutics.com/role/ConsolidatedBalanceSheets Consolidated Balance Sheets Statements 2 false false R3.htm 9952152 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.cartesiantherapeutics.com/role/ConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 3 false false R4.htm 9952153 - Statement - Consolidated Statements of Operations and Comprehensive Income (Loss) Sheet http://www.cartesiantherapeutics.com/role/ConsolidatedStatementsofOperationsandComprehensiveIncomeLoss Consolidated Statements of Operations and Comprehensive Income (Loss) Statements 4 false false R5.htm 9952155 - Statement - Consolidated Statements of Changes in Stockholders’ Deficit Sheet http://www.cartesiantherapeutics.com/role/ConsolidatedStatementsofChangesinStockholdersDeficit Consolidated Statements of Changes in Stockholders’ Deficit Statements 5 false false R6.htm 9952156 - Statement - Consolidated Statements of Cash Flows Sheet http://www.cartesiantherapeutics.com/role/ConsolidatedStatementsofCashFlows Consolidated Statements of Cash Flows Statements 6 false false R7.htm 9952157 - Disclosure - Description of the Business Sheet http://www.cartesiantherapeutics.com/role/DescriptionoftheBusiness Description of the Business Notes 7 false false R8.htm 9952158 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.cartesiantherapeutics.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 8 false false R9.htm 9952159 - Disclosure - Goodwill and Indefinite-Lived Intangible Assets Sheet http://www.cartesiantherapeutics.com/role/GoodwillandIndefiniteLivedIntangibleAssets Goodwill and Indefinite-Lived Intangible Assets Notes 9 false false R10.htm 9952160 - Disclosure - Net Income (Loss) Per Share Allocable to Common Stockholders Sheet http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholders Net Income (Loss) Per Share Allocable to Common Stockholders Notes 10 false false R11.htm 9952161 - Disclosure - Fair Value Measurements Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurements Fair Value Measurements Notes 11 false false R12.htm 9952162 - Disclosure - Property and Equipment Sheet http://www.cartesiantherapeutics.com/role/PropertyandEquipment Property and Equipment Notes 12 false false R13.htm 9952163 - Disclosure - Accrued Expenses Sheet http://www.cartesiantherapeutics.com/role/AccruedExpenses Accrued Expenses Notes 13 false false R14.htm 9952164 - Disclosure - Leases Sheet http://www.cartesiantherapeutics.com/role/Leases Leases Notes 14 false false R15.htm 9952165 - Disclosure - Debt Sheet http://www.cartesiantherapeutics.com/role/Debt Debt Notes 15 false false R16.htm 9952166 - Disclosure - Equity Sheet http://www.cartesiantherapeutics.com/role/Equity Equity Notes 16 false false R17.htm 9952167 - Disclosure - Stock Incentive Plans Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlans Stock Incentive Plans Notes 17 false false R18.htm 9952168 - Disclosure - Revenue Arrangements Sheet http://www.cartesiantherapeutics.com/role/RevenueArrangements Revenue Arrangements Notes 18 false false R19.htm 9952169 - Disclosure - Collaboration and License Agreements Sheet http://www.cartesiantherapeutics.com/role/CollaborationandLicenseAgreements Collaboration and License Agreements Notes 19 false false R20.htm 9952170 - Disclosure - Income Taxes Sheet http://www.cartesiantherapeutics.com/role/IncomeTaxes Income Taxes Notes 20 false false R21.htm 9952171 - Disclosure - Commitments and Contingencies Sheet http://www.cartesiantherapeutics.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 21 false false R22.htm 9952172 - Disclosure - Segment Reporting Sheet http://www.cartesiantherapeutics.com/role/SegmentReporting Segment Reporting Notes 22 false false R23.htm 9952173 - Disclosure - Subsequent Events Sheet http://www.cartesiantherapeutics.com/role/SubsequentEvents Subsequent Events Notes 23 false false R24.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 24 false false R25.htm 9955511 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.cartesiantherapeutics.com/role/SummaryofSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.cartesiantherapeutics.com/role/SummaryofSignificantAccountingPolicies 25 false false R26.htm 9955512 - Disclosure - Net Income (Loss) Per Share Allocable to Common Stockholders (Tables) Sheet http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholdersTables Net Income (Loss) Per Share Allocable to Common Stockholders (Tables) Tables http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholders 26 false false R27.htm 9955513 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.cartesiantherapeutics.com/role/FairValueMeasurements 27 false false R28.htm 9955514 - Disclosure - Property and Equipment (Tables) Sheet http://www.cartesiantherapeutics.com/role/PropertyandEquipmentTables Property and Equipment (Tables) Tables http://www.cartesiantherapeutics.com/role/PropertyandEquipment 28 false false R29.htm 9955515 - Disclosure - Accrued Expenses (Tables) Sheet http://www.cartesiantherapeutics.com/role/AccruedExpensesTables Accrued Expenses (Tables) Tables http://www.cartesiantherapeutics.com/role/AccruedExpenses 29 false false R30.htm 9955516 - Disclosure - Leases (Tables) Sheet http://www.cartesiantherapeutics.com/role/LeasesTables Leases (Tables) Tables http://www.cartesiantherapeutics.com/role/Leases 30 false false R31.htm 9955517 - Disclosure - Debt (Tables) Sheet http://www.cartesiantherapeutics.com/role/DebtTables Debt (Tables) Tables http://www.cartesiantherapeutics.com/role/Debt 31 false false R32.htm 9955518 - Disclosure - Equity (Tables) Sheet http://www.cartesiantherapeutics.com/role/EquityTables Equity (Tables) Tables http://www.cartesiantherapeutics.com/role/Equity 32 false false R33.htm 9955519 - Disclosure - Stock Incentive Plans (Tables) Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlansTables Stock Incentive Plans (Tables) Tables http://www.cartesiantherapeutics.com/role/StockIncentivePlans 33 false false R34.htm 9955520 - Disclosure - Segment Reporting (Tables) Sheet http://www.cartesiantherapeutics.com/role/SegmentReportingTables Segment Reporting (Tables) Tables http://www.cartesiantherapeutics.com/role/SegmentReporting 34 false false R35.htm 9955521 - Disclosure - Description of the Business (Details) Sheet http://www.cartesiantherapeutics.com/role/DescriptionoftheBusinessDetails Description of the Business (Details) Details http://www.cartesiantherapeutics.com/role/DescriptionoftheBusiness 35 false false R36.htm 9955522 - Disclosure - Goodwill and Indefinite-Lived Intangible Assets (Details) Sheet http://www.cartesiantherapeutics.com/role/GoodwillandIndefiniteLivedIntangibleAssetsDetails Goodwill and Indefinite-Lived Intangible Assets (Details) Details http://www.cartesiantherapeutics.com/role/GoodwillandIndefiniteLivedIntangibleAssets 36 false false R37.htm 9955523 - Disclosure - Net Income (Loss) Per Share Allocable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share Allocable to Common Stockholders (Details) Sheet http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholdersScheduleofComputationofBasicandDilutedNetIncomeLossPerShareAllocabletoCommonStockholdersDetails Net Income (Loss) Per Share Allocable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share Allocable to Common Stockholders (Details) Details http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholdersTables 37 false false R38.htm 9955524 - Disclosure - Net Income (Loss) Per Share Allocable to Common Stockholders - Schedule of Potential Dilutive Shares of Common Stock Excluded from the Computation of the Diluted Net Income (Loss) Per Share Allocable to Common Stockholders (Details) Sheet http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholdersScheduleofPotentialDilutiveSharesofCommonStockExcludedfromtheComputationoftheDilutedNetIncomeLossPerShareAllocabletoCommonStockholdersDetails Net Income (Loss) Per Share Allocable to Common Stockholders - Schedule of Potential Dilutive Shares of Common Stock Excluded from the Computation of the Diluted Net Income (Loss) Per Share Allocable to Common Stockholders (Details) Details http://www.cartesiantherapeutics.com/role/NetIncomeLossPerShareAllocabletoCommonStockholdersTables 38 false false R39.htm 9955525 - Disclosure - Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsScheduleofAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) Details 39 false false R40.htm 9955526 - Disclosure - Fair Value Measurements - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsNarrativeDetails Fair Value Measurements - Narrative (Details) Details 40 false false R41.htm 9955527 - Disclosure - Fair Value Measurements - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsScheduleofCashCashEquivalentsandRestrictedCashDetails Fair Value Measurements - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) Details 41 false false R42.htm 9955528 - Disclosure - Fair Value Measurements - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsScheduleofFairValueMeasurementInputsandValuationTechniquesDetails Fair Value Measurements - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details) Details 42 false false R43.htm 9955529 - Disclosure - Fair Value Measurements - Schedule of Roll-Forward of Fair Value (Details) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsScheduleofRollForwardofFairValueDetails Fair Value Measurements - Schedule of Roll-Forward of Fair Value (Details) Details 43 false false R44.htm 9955530 - Disclosure - Fair Value Measurements - Schedule of Fair Value Measurement Inputs and Valuation Techniques for CVR Liability (Details) Sheet http://www.cartesiantherapeutics.com/role/FairValueMeasurementsScheduleofFairValueMeasurementInputsandValuationTechniquesforCVRLiabilityDetails Fair Value Measurements - Schedule of Fair Value Measurement Inputs and Valuation Techniques for CVR Liability (Details) Details 44 false false R45.htm 9955531 - Disclosure - Property and Equipment - Schedule of Property and Equipment (Details) Sheet http://www.cartesiantherapeutics.com/role/PropertyandEquipmentScheduleofPropertyandEquipmentDetails Property and Equipment - Schedule of Property and Equipment (Details) Details 45 false false R46.htm 9955532 - Disclosure - Property and Equipment - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/PropertyandEquipmentNarrativeDetails Property and Equipment - Narrative (Details) Details 46 false false R47.htm 9955533 - Disclosure - Accrued Expenses (Details) Sheet http://www.cartesiantherapeutics.com/role/AccruedExpensesDetails Accrued Expenses (Details) Details http://www.cartesiantherapeutics.com/role/AccruedExpensesTables 47 false false R48.htm 9955534 - Disclosure - Leases - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/LeasesNarrativeDetails Leases - Narrative (Details) Details 48 false false R49.htm 9955535 - Disclosure - Leases - Schedule of Components of Lease Costs (Details) Sheet http://www.cartesiantherapeutics.com/role/LeasesScheduleofComponentsofLeaseCostsDetails Leases - Schedule of Components of Lease Costs (Details) Details 49 false false R50.htm 9955536 - Disclosure - Leases - Schedule of Maturity of Operating Lease Liabilities (Details) Sheet http://www.cartesiantherapeutics.com/role/LeasesScheduleofMaturityofOperatingLeaseLiabilitiesDetails Leases - Schedule of Maturity of Operating Lease Liabilities (Details) Details 50 false false R51.htm 9955537 - Disclosure - Leases - Schedule of Other Information Related to Operating Leases (Details) Sheet http://www.cartesiantherapeutics.com/role/LeasesScheduleofOtherInformationRelatedtoOperatingLeasesDetails Leases - Schedule of Other Information Related to Operating Leases (Details) Details 51 false false R52.htm 9955538 - Disclosure - Debt - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/DebtNarrativeDetails Debt - Narrative (Details) Details 52 false false R53.htm 9955539 - Disclosure - Debt - Schedule of Outstanding Balance (Details) Sheet http://www.cartesiantherapeutics.com/role/DebtScheduleofOutstandingBalanceDetails Debt - Schedule of Outstanding Balance (Details) Details 53 false false R54.htm 9955540 - Disclosure - Debt - Schedule of Interest Expense (Details) Sheet http://www.cartesiantherapeutics.com/role/DebtScheduleofInterestExpenseDetails Debt - Schedule of Interest Expense (Details) Details 54 false false R55.htm 9955541 - Disclosure - Debt - Schedule of Future Minimum Payments on the Term Loans (Details) Sheet http://www.cartesiantherapeutics.com/role/DebtScheduleofFutureMinimumPaymentsontheTermLoansDetails Debt - Schedule of Future Minimum Payments on the Term Loans (Details) Details 55 false false R56.htm 9955542 - Disclosure - Equity - “At the Market” Sales Agreement - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/EquityAttheMarketSalesAgreementNarrativeDetails Equity - “At the Market” Sales Agreement - Narrative (Details) Details 56 false false R57.htm 9955543 - Disclosure - Equity - Warrants - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/EquityWarrantsNarrativeDetails Equity - Warrants - Narrative (Details) Details 57 false false R58.htm 9955544 - Disclosure - Equity - Schedule of Warranty Activity (Details) Sheet http://www.cartesiantherapeutics.com/role/EquityScheduleofWarrantyActivityDetails Equity - Schedule of Warranty Activity (Details) Details 58 false false R59.htm 9955545 - Disclosure - Equity - Preferred Stock - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/EquityPreferredStockNarrativeDetails Equity - Preferred Stock - Narrative (Details) Details 59 false false R60.htm 9955546 - Disclosure - Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Details) Sheet http://www.cartesiantherapeutics.com/role/EquityScheduleofReservedSharesofCommonStockforFutureIssuanceDetails Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Details) Details 60 false false R61.htm 9955547 - Disclosure - Stock Incentive Plans - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlansNarrativeDetails Stock Incentive Plans - Narrative (Details) Details 61 false false R62.htm 9955548 - Disclosure - Stock Incentive Plans - Schedule of Stock-Based Compensation Expense (Details) Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlansScheduleofStockBasedCompensationExpenseDetails Stock Incentive Plans - Schedule of Stock-Based Compensation Expense (Details) Details 62 false false R63.htm 9955549 - Disclosure - Stock Incentive Plans - Schedule of Weighted Average Assumptions Used (Details) Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlansScheduleofWeightedAverageAssumptionsUsedDetails Stock Incentive Plans - Schedule of Weighted Average Assumptions Used (Details) Details 63 false false R64.htm 9955550 - Disclosure - Stock Incentive Plans - Schedule of Stock Option Activity (Details) Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlansScheduleofStockOptionActivityDetails Stock Incentive Plans - Schedule of Stock Option Activity (Details) Details 64 false false R65.htm 9955551 - Disclosure - Stock Incentive Plans - Schedule of Restricted Stock Units Activity (Details) Sheet http://www.cartesiantherapeutics.com/role/StockIncentivePlansScheduleofRestrictedStockUnitsActivityDetails Stock Incentive Plans - Schedule of Restricted Stock Units Activity (Details) Details 65 false false R66.htm 9955552 - Disclosure - Revenue Arrangements (Details) Sheet http://www.cartesiantherapeutics.com/role/RevenueArrangementsDetails Revenue Arrangements (Details) Details http://www.cartesiantherapeutics.com/role/RevenueArrangements 66 false false R67.htm 9955553 - Disclosure - Collaboration and License Agreements - WestGene Biopharma Co., Ltd. - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/CollaborationandLicenseAgreementsWestGeneBiopharmaCoLtdNarrativeDetails Collaboration and License Agreements - WestGene Biopharma Co., Ltd. - Narrative (Details) Details 67 false false R68.htm 9955554 - Disclosure - Collaboration and License Agreements - Biogen M.A., Inc. - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/CollaborationandLicenseAgreementsBiogenMAIncNarrativeDetails Collaboration and License Agreements - Biogen M.A., Inc. - Narrative (Details) Details 68 false false R69.htm 9955555 - Disclosure - Collaboration and License Agreements - National Cancer Institute of the National Institutes of Health - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/CollaborationandLicenseAgreementsNationalCancerInstituteoftheNationalInstitutesofHealthNarrativeDetails Collaboration and License Agreements - National Cancer Institute of the National Institutes of Health - Narrative (Details) Details 69 false false R70.htm 9955556 - Disclosure - Collaboration and License Agreements - Shenyang Sunshine Pharmaceutical Co., Ltd - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/CollaborationandLicenseAgreementsShenyangSunshinePharmaceuticalCoLtdNarrativeDetails Collaboration and License Agreements - Shenyang Sunshine Pharmaceutical Co., Ltd - Narrative (Details) Details 70 false false R71.htm 9955557 - Disclosure - Segment Reporting - Narrative (Details) Sheet http://www.cartesiantherapeutics.com/role/SegmentReportingNarrativeDetails Segment Reporting - Narrative (Details) Details 71 false false R72.htm 9955558 - Disclosure - Segment Reporting - Schedule of Segment Reporting Information, by Segment (Details) Sheet http://www.cartesiantherapeutics.com/role/SegmentReportingScheduleofSegmentReportingInformationbySegmentDetails Segment Reporting - Schedule of Segment Reporting Information, by Segment (Details) Details 72 false false All Reports Book All Reports rnac-20260630.htm rnac-20260630.xsd rnac-20260630_cal.xml rnac-20260630_def.xml rnac-20260630_lab.xml rnac-20260630_pre.xml http://fasb.org/us-gaap/2026 http://xbrl.sec.gov/dei/2026 http://xbrl.sec.gov/ecd/2026 true true