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Invagen Pharmaceuticals Inc [Member] Represents Invagen Pharmaceuticals,Inc. Accounting Policies [Abstract] Fortress [Member] Represens Fortress. Measurement Input Type [Axis] Counterparty Name [Domain] Income Statement [Abstract] us-gaap_SharesOutstanding Balance (in shares) Balance (in shares) us-gaap_NumberOfOperatingSegments Number of Operating Segments atxi_CommissionFeePercentFee Commission Fee, Percent Fee Pertains to the commission fee. us-gaap_NumberOfReportableSegments Number of Reportable Segments ATM Agreement [Member] Information pertaining to the sale of stock. atxi_ResearchAndDevelopmentExpenseLicensesAcquired Research And Development Expense, Licenses Acquired Amount of research and development expenses attributable to licenses acquired. Noncontrolling Interests [Policy Text Block] Disclosure of accounting policy for non-controlling interests. Measurement Input, Expected Dividend Rate [Member] Measurement Input, Expected Term [Member] Change in fair value of warrant liabilities Change in fair value of warrant liabilities Class A Preferred Shares [Member] Represents class A preferred shares. atxi_PercentageOfEquityFee Percentage of Equity Fee Represents percentage of equity fee. Award Type [Axis] Net loss attributable to common stockholders Net loss attributable to common stockholders Reconciliation of net loss to net cash used in operating activities: Measurement Input, Price Volatility [Member] Preferred stock Fortress Biotech Inc [Member] Represents Fortress Biotech Inc. Plan Name [Axis] us-gaap_Liabilities Total liabilities Plan Name [Domain] License Agreement Disclosure [Text Block] The entire disclosure of license agreement. atxi_ContractualObligationMaximumFuturePayments Contractual Obligation, Maximum Future Payments Maximum future payments for contractual obligation. 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Founders Agreement and Management Services Agreement [Member] Represents founders agreement and management services agreement. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber Unvested balance (in shares) Unvested balance (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue Unvested balance, weighted average grant date fair value (in dollars per share) Unvested balance, Weighted average grant date fair value (in dollars per share) BaergicBio, Inc.[Member] Represents BaergicBioInc. Product and Service [Domain] Avenue Baergic Founders Agreement [Member] Represents Avenue Baergic Founders Agreement. Product and Service [Axis] atxi_PercentageConsideredForTheCalculationOfOnetimeFee Percentage Considered For The Calculation Of One-Time Fee Represents percentage of considered for the calculation of one -time fee. 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