Adjustments to reconcile net income (loss) to net cash used in operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Statistical Measurement [Domain] Statistical Measurement [Domain] Takeda Pharmaceuticals U.S.A., Inc. Takeda Pharmaceuticals U.S.A., Inc. [Member] Takeda Pharmaceuticals U.S.A., Inc. Total duration of consecutive and overlapping offering periods Share Based Compensation Arrangement by Share Based Payment Award, Consecutive and Overlapping Offering Period Share Based Compensation Arrangement by Share Based Payment Award, Consecutive and Overlapping Offering Period Schedule of Prepaid Expenses and Other Current Assets Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] Cover [Abstract] NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Preclinical & development expenses Preclinical & Development Expenses [Member] Preclinical & Development Expenses Other Other Liabilities, Current Tech Transfer Agreement Tech Transfer Agreement [Member] Tech Transfer Agreement Trading Symbol Trading Symbol Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Risk and Uncertainties 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Nonoperating Income (Expense) Effective tax rate Effective Income Tax Rate Reconciliation, Percent Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities INCOME (LOSS) FROM OPERATIONS Operating Income (Loss) Hansoh Shanghai Healthtech Co Ltd Hansoh Shanghai Healthtech Co Ltd [Member] Hansoh Shanghai Healthtech Co Ltd Number of additional shares authorized (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized Number of reportable segments Number of Reportable Segments TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity SUBSEQUENT EVENTS Subsequent Events [Text Block] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] All Adjustments to Compensation All Adjustments to Compensation [Member] Accrued compensation and benefits Employee-related Liabilities, Current Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Prepaid expenses and 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Tax Disclosure [Abstract] Name Trading Arrangement, Individual Name Other expense, net Other Nonoperating Income (Expense) Statement of Stockholders' Equity [Abstract] Weighted Average Grant-Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Assets Assets, Fair Value Disclosure [Abstract] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Common stock, reserved for future issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable 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Adjustments [Member] Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Underlying Securities Award Underlying Securities Amount Amendment Flag Amendment Flag Entity Registrant Name Entity Registrant Name Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Fair Value as of Grant Date Award Grant Date Fair Value Subsequent Events [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Sale of stock, number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2) Fair Value, Inputs, Level 2 [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Issuance of common stock, net of underwriting discounts, commissions and offering costs of $0 Stock Issued During Period, Value, New Issues Entity Address, Postal Zip Code Entity Address, Postal Zip Code Schedule of Stock-Based Compensation Expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Accrued external manufacturing costs Accrued Manufacturing Costs, Current Accrued Manufacturing Costs, Current Restatement Determination Date: Restatement Determination Date [Axis] Title of 12(b) Security Title of 12(b) Security Common stock, par value of $0.0001 per share; 200,000,000 shares authorized as of March 31, 2025 and December 31, 2024; 40,562,047 and 40,554,705 shares issued and outstanding as of March 31, 2025 and December 31, 2024, respectively Common Stock, Value, Issued Share-Based Payment Arrangement [Abstract] Cash and cash equivalents Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Prepaid external R&D costs Prepaid External R&D Costs, Current Prepaid External R&D Costs, Current Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Forfeited (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Preferred stock, par value of $0.0001 per share; 10,000,000 shares authorized as of March 31, 2025 and December 31, 2024; no shares issued and outstanding Preferred Stock, Value, Issued NUMBER 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equipment purchases in accounts payable and accrued expenses Capital Expenditures Incurred but Not yet Paid Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Net income (loss) attributable to common stockholders - basic Net Income (Loss) Available to Common Stockholders, Basic Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Total current liabilities Liabilities, Current Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] TOTAL ASSETS Assets Share based compensation arrangement by share based payment award, annual increase percent of shares outstanding Share Based Compensation Arrangement by Share Based Payment Award, Annual Increase Percent of Shares Outstanding Share Based Compensation Arrangement by Share Based Payment Award, Annual Increase Percent of Shares Outstanding Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Over-Allotment Option Over-Allotment Option [Member] Purchase of property and equipment Payments to Acquire Property, Plant, and Equipment Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Stock-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Termination Date Trading Arrangement Termination Date Total revenue from Takeda Revenues Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Revenue, remaining performance obligation, development milestones, variable consideration Revenue, Remaining Performance Obligation, Development Milestones, Variable Consideration Revenue, Remaining Performance Obligation, Development Milestones, Variable Consideration STOCK-BASED COMPENSATION Share-Based Payment Arrangement [Text Block] Entity Address, City or Town Entity Address, City or Town Debt Instrument [Axis] Debt Instrument [Axis] Schedule of Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Aggregate intrinsic value of stock options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Total stock-based compensation expense Stock-based compensation Share-Based Payment Arrangement, Expense Net income (loss) Net income (loss) Net income (loss) Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Upfront license fee Revenue from Contract with Customer, Including Assessed Tax Granted (in USD per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period KER-065 program expenses KER-065 Program Expenses [Member] KER-065 Program Expenses Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Entity File Number Entity File Number REVENUE FROM CONTRACTS WITH CUSTOMERS Revenue from Contract with Customer [Text Block] Document Fiscal Year Focus Document Fiscal Year Focus Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Denominator: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Entity Address, Address Line Two Entity Address, Address Line Two Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Total financial assets Assets, Fair Value Disclosure Name Forgone Recovery, Individual Name Options exercisable, value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Document Period End Date Document Period End Date Sale of Stock [Axis] Sale of Stock [Axis] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Outstanding as of beginning of period (in shares) Outstanding as of end of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Expired (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Expirations in Period Insider Trading Arrangements [Line Items] Withholding taxes from upfront fee Revenue From Contract With Customer, Withholding Taxes Revenue From Contract With Customer, Withholding Taxes Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Adjustment to Compensation: Adjustment to Compensation [Axis] Prepaid expenses and other current assets Total prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Document Transition Report Document Transition Report Document Quarterly Report Document Quarterly Report Purchase obligation Purchase Obligation Payment of issuance costs Payment Of Initial Public Offering Costs Payment Of Initial Public Offering Costs License revenue License revenue [Member] License revenue Customer [Domain] Customer [Domain] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Entity Current Reporting Status Entity Current Reporting Status ACCUMULATED DEFICIT Retained Earnings [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Weighted average shares of common stock outstanding - Basic (in shares) Weighted-average common stock outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Restricted stock unit awards Restricted Stock Units (RSUs) [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Accrued legal and consulting fees Accrued Professional Fees, Current Executive Category: Executive Category [Axis] Name Awards Close in Time to MNPI Disclosures, Individual Name Cancelled or Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Prepaid sales tax Sales Tax Receivable, Current Sales Tax Receivable, Current Entity Filer Category Entity Filer Category Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Company Selected Measure Name Company Selected Measure Name