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Entity File Number phio_NumberOfWarrantsPerUnit Number of Warrants per Unit (in shares) Number of warrants issued per unit Entity Tax Identification Number Placement Agent Warrants, Two [Member] Placement Agent Warrants, Two Placement Agent Warrants, One [Member] Placement Agent Warrants, One Entity [Domain] Entity Central Index Key Entity Registrant Name Entity Current Reporting Status Entity Incorporation, State or Country Code January 14, 2025 Offerings [Member] January 14, 2025 Offerings Proceeds from sale of property and equipment January 13, 2025 Offerings [Member] January 13, 2025 Offerings Current Fiscal Year End Date July 2025 Financing [Member] July 2025 Financing Placement Agent Warrants, Three [Member] Placement Agent Warrants, Three Capitalization, Equity [Table] Research and development Research and development Entity Filer Category Entity Shell Company Entity Emerging Growth Company Entity Small Business us-gaap_OperatingIncomeLoss Operating loss Issuance of common stock and warrants, net of offering costs (in shares) The number of shares and warrants issued during the period Net proceeds from the issuance of common stock and warrants Amount of Proceeds from Issuance of Common Stock and Warrants Issuance of common stock upon exercise of warrants Value of shares issued during the period from the exercise of warrants. Issuance of common stock upon exercise of warrants (in shares) The number of shares issued during the period from the exercise of warrants. Issuance of common stock and warrants, net of offering costs Value of shares and warrants issued during the period. Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] AgonOx [Member] Represent AgonOx. Laboratory Facility, Worcester, Massachusetts [Member] Represent Laboratory Facility, Worcester, Massachusetts. Offsetting Assets [Table] Collaborative Arrangement, Clinical Co-Development Agreement [Member] Represent Collaborative Arrangement, Clinical Co-Development Agreement. phio_EquityIssuableMaximumValue Equity Issuable, Maximum Value The maximum value of shares issuable under offering. Entity Address, State or Province Statement of Stockholders' Equity [Abstract] Entity Address, City or Town Former Corporate Headquarters [Member] Represent former corporate headquarters. Accumulated deficit Entity Address, Address Line One Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Statement of Cash Flows [Abstract] City Area Code Common Stock Warrants [Member] Represent Common Stock Warrants. Local Phone Number Entity Address, Postal Zip Code phio_PolicyTable Existing Warrants [Member] Represent existing Warrants. Title of 12(b) Security Equity Components [Axis] Security Exchange Name Registered Direct Offering [Member] Represent Registered Direct Offering. Trading Symbol H.C. Wainwright & Co., LLC [Member] Represent H.C. Wainwright & Co., LLC. phio_OperatingLeasesMonthlyPayment Operating Leases, Monthly Payment Amount of monthly rental payment under operating lease. Class of Stock [Axis] Equity Component [Domain] us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) Placement Agent Warrants [Member] Represent Placement Agent Warrants. Equity [Text Block] Entity Common Stock, Shares Outstanding Additional Paid-in Capital [Member] us-gaap_ClassOfWarrantOrRightOutstanding Outstanding (in shares) Outstanding (in shares) Retained Earnings [Member] Earnings Per Share [Text Block] phio_ClassOfWarrantOrRightExpiredDuringPeriod Expired (in shares) The number of warrants or rights expired during period. phio_ClassOfWarrantOrRightExercisedDuringPeriod Class of Warrant or Right, Exercised During Period (in shares) Exercised (in shares) The number of warrants or rights exercised during period. Property and equipment, net Exercised (in dollars per share) Class of Warrant or Right, Exercised During Period, Exercise Price (in dollars per share) Exercise price per share of warrants or rights exercised during period. Issued (in shares) The number of warrants or rights issued during period. Series H Warrants [Member] Represent Series H Warrants. Series G Warrants [Member] Represent Series G Warrants. Series I Warrants [Member] Represent Series I Warrants. phio_ClassOfWarrantOrRightPurchasePriceOfWarrantsOrRights Class of Warrant or Right, Purchase Price of Warrants or Rights (in dollars per share) Purchase price per share or per unit of warrants or rights outstanding. Expired, weighted average exercise price per share (in dollars per share) Exercise price per share of warrants or rights expired during period. Issued, weighted average exercise price per share (in dollars per share) Exercise price per share of warrants or rights issued during period. The 2020 Plan [Member] Represent The 2020 Plan. New Warrants, July 2025 [Member] Represent New Warrants, July 2025. Sale of Stock [Axis] Net proceeds from the exercise of warrants Proceeds from Warrant Exercises Existing Warrants, December 2024 [member] Represent Existing Warrants, December 2024. Existing Warrants, January 2025 [Member] Represent Existing Warrants, January 2025. Common stock, par value (in dollars per share) Stock-based compensation expense Series K Warrants [Member] Represent Serries K Warrants. Basis of Accounting, Policy [Policy Text Block] Series J Warrants [Member] Represent Series J Warrants. us-gaap_OtherNonoperatingIncome Other income, net Other income (expense), net Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Sale of Stock [Domain] us-gaap_Assets Total assets Cash and cash equivalents Accounts Payable and Accrued Liabilities Disclosure [Text Block] Share-Based Payment Arrangement, Option [Member] Current liabilities: Depreciation and amortization Liquidity [Policy Text Block] Disclosure of the accounting policy for the companies liquidity. phio_ResearchAndDevelopmentAccruals Research and development accruals The amount of accrued research and development. Consolidation, Policy [Policy Text Block] phio_ClassOfWarrantOrRightExercisedDuringPeriodAtAReducedPrice Class of Warrant or Right, Exercised During Period at a Reduced Price (in shares) The number of warrants exercised at a reduced price during the period. General and Administrative [Member] General and Administrative Common Stock Outstanding [Member] Represent Common Stock Outstanding. Employee Related Research Expenses [Member] Represents the employee related research expenses. Research and Development [Member] Research and Development Research of PH-894 [Member] Represents the research of PH-894. Research of PH-762 [Member] Represents the research of PH-762. us-gaap_GainLossOnSaleOfPropertyPlantEquipment Net gain on disposal of property and equipment New Warrants, November 2025 [Member] Represents the new November 2025 warrants. Existing Warrants, July 2025 [Member] Represents the existing July 2025 warrants. November 2025 Financing [Member] Represents the November 2025 financing. Series A Warrants [Member] Represents the series A warrants. 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