Document and Entity Information Document Information [Table] Class of Stock [Axis] Class of Stock [Domain] Common Stock [Member] Ordinary Shares ADR [Member] American Depositary Shares Represents information pertaining to non-voting ordinary shares. Non voting ordinary shares Non-voting ordinary shares Document Information [Line Items] Document Information Document Type Document Quarterly Report Document Period End Date Document Transition Report Securities Act File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, Country Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security No Trading Symbol Flag No Trading Symbol Flag Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag Condensed Consolidated Balance Sheets Statement [Table] Statement [Line Items] Statement Assets [Abstract] Assets Assets, Current [Abstract] Current assets: Cash and Cash Equivalent Cash and cash equivalents Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Amount of research and development incentives receivables, classified as current. Research and Development Incentives Receivable, Current Research and development incentives receivable Assets, Current Total current assets Property, Plant and Equipment, Net Property and equipment, net Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Other Assets, Noncurrent Other assets Assets Total assets Liabilities and Equity [Abstract] Liabilities and shareholders' equity Liabilities, Current [Abstract] Current liabilities: Accounts Payable, Current Accounts payable Accrued Liabilities, Current Accrued expenses and other current liabilities Accrued expenses and other current liabilities Deferred Revenue, Current Deferred revenue, current portion Liabilities, Current Total current liabilities Operating Lease, Liability, Noncurrent Long term lease liabilities Operating lease liabilities, net of current portion Deferred Revenue, Noncurrent Deferred revenue, net of current portion Other Liabilities, Noncurrent Other long-term liabilities Liabilities Total liabilities Commitments and Contingencies. Commitments and contingencies (Note 10) Equity, Attributable to Parent [Abstract] Shareholders' equity: Common Stock, Value, Issued Ordinary shares, including non-voting ordinary shares, £0.01 nominal value; 163,361,109 and 159,685,229 shares authorized on March 31, 2026 and December 31, 2025, respectively; 69,707,026 and 69,367,896 shares issued and outstanding at March 31, 2026 and December 31, 2025, respectively Additional Paid in Capital Additional paid-in capital Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Retained Earnings (Accumulated Deficit) Accumulated deficit Equity, Attributable to Parent Ending balance Beginning balance Total shareholders' equity Liabilities and Equity Total liabilities and shareholders' equity Common Stock, Par or Stated Value Per Share Ordinary shares, nominal value Common Stock, Shares Authorized Ordinary shares, shares authorized Common Stock, Shares, Issued Ordinary shares, shares issued Common Stock, Shares, Outstanding Ending balance (in shares) Beginning balance (in shares) Ordinary shares, shares outstanding Condensed Consolidated Statements of Operations and Comprehensive Loss Revenue from Contract with Customer, Excluding Assessed Tax Collaboration revenue Revenue from collaborative arrangement Operating Expenses [Abstract] Operating expenses: Significant segment expenses: Research and Development Expense Research and development Total research and development General and Administrative Expense General and administrative Total general and administrative Operating Expenses Total operating expenses Operating Income (Loss) Loss from operations Nonoperating Income (Expense) [Abstract] Other income (expense): Interest and Other Income Interest and other income Interest Expense, Nonoperating Interest expense Nonoperating Income (Expense) Total other income, net Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Net loss before income tax provision Income Tax Expense (Benefit) Provision for (benefit from) income taxes Net loss Net loss Earnings Per Share, Basic Net loss per share, basic (in dollars per share) Earnings Per Share, Diluted Net loss per share, diluted (in dollars per share) Weighted Average Number of Shares Outstanding, Basic Weighted average ordinary shares outstanding, basic (in shares) Weighted Average Number of Shares Outstanding, Diluted Weighted average ordinary shares outstanding, diluted (in shares) Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Comprehensive loss: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Foreign currency translation adjustment Comprehensive Income (Loss), Net of Tax, Attributable to Parent Total comprehensive loss Condensed Consolidated Statements of Shareholders' Equity Equity Components [Axis] Equity Component [Domain] Additional Paid-in Capital [Member] Additional Paidin Capital AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Retained Earnings [Member] Accumulated Deficit Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (decrease) in shareholders' equity (deficit) Stock Issued During Period, Value, Stock Options Exercised Issuance of ADSs upon exercise of share options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Exercised Issuance of ADSs upon exercise of share options (in shares) Stock Issued During Period, Value, Restricted Stock Award, Gross Issuance of ADSs upon settlement of restricted share units Stock Issued During Period, Shares, Restricted Stock Award, Gross Issuance of ADSs upon settlement of restricted share units (in shares) APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Share-based compensation expense Condensed Consolidated Statements of Cash Flows Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Cash flows from operating activities: Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Adjustments to reconcile net loss to net cash used in operating activities: Share-Based Payment Arrangement, Noncash Expense Share-based compensation expense Depreciation, Depletion and Amortization Depreciation and amortization Deferred Income Tax Expense (Benefit) Deferred income tax benefit Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Accounts Receivable Accounts receivable The increase (decrease) during the reporting period in amount due within one year (or one business cycle) for research and development incentives receivable. Increase (Decrease) in Research and Development Incentives Receivable Research and development incentives receivable Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other assets The increase (decrease) during the period in the carrying value of operating lease right-of-use assets reported as assets that are due to be disposed of within one year (or the normal operating cycle, if longer). Increase (Decrease) in Operating Lease Right-of-use Assets Operating lease right-of-use assets Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Accrued expenses and other current liabilities Increase (Decrease) in Operating Lease Liability Operating lease liabilities Increase (Decrease) in Deferred Revenue Deferred revenue Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Net cash used in operating activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Cash flows from investing activities: Payments to Acquire Property, Plant, and Equipment Purchases of property and equipment Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Net cash used in investing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Cash flows from financing activities: Proceeds from Stock Options Exercised Proceeds from the exercise of share options and settlement of restricted share units Finance Lease, Principal Payments Payments of finance lease obligations Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Net cash used in financing activities Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Effect of exchange rate changes on cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Net decrease in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Cash, cash equivalents and restricted cash at end of period Cash, cash equivalents and restricted cash at beginning of period Total cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Reconciliation of cash, cash equivalents and restricted cash Restricted Cash and Cash Equivalent Restricted cash in prepaid expenses and other current assets, and other assets, respectively Restricted Cash and Cash Equivalent, Statement of Financial Position [Extensible Enumeration] Restricted Cash Equivalent, Current Restricted cash in prepaid expenses and other current assets Restricted Cash and Cash Equivalent, Noncurrent Restricted cash in other assets Supplemental Cash Flow Elements [Abstract] Supplemental disclosure of cash flow information Finance Lease, Interest Payment on Liability Cash paid for interest on finance lease obligations Operating Lease, Payments Cash paid for amounts included in the measurement of operating lease liabilities Increase or decrease in future cash outflow to pay for purchases of fixed assets that have occurred. Increase Decrease Capital Expenditures Incurred but Not yet Paid Changes in purchases of property and equipment in accounts payable and accrued expenses Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Non-cash impact to operating lease right-of-use assets and operating lease liabilities Nature of the business and basis of presentation Business Description and Basis of Presentation [Text Block] Nature of the business and basis of presentation Summary of significant accounting policies Significant Accounting Policies [Text Block] Summary of significant accounting policies Fair value of financial assets and liabilities Fair Value Disclosures [Text Block] Fair value of financial assets and liabilities Property and equipment, net Property, Plant and Equipment Disclosure [Text Block] Property and equipment, net No definition available. Accrued expenses and other current liabilities The entire disclosure for accrued expenses and other liabilities that are classified as current at the end of the reporting period. Accrued Liabilities and Other Liabilities Disclosure, Current [Text Block] Accrued expenses and other current liabilities Ordinary shares Equity [Text Block] Ordinary shares Share-based compensation Share-Based Payment Arrangement [Text Block] Share-based compensation Significant agreements Revenue from Contract with Customer [Text Block] Significant agreements Income taxes Income Tax Disclosure [Text Block] Income taxes Commitments and contingencies Commitments and Contingencies Disclosure [Text Block] Commitments and contingencies Net loss per share Earnings Per Share [Text Block] Net loss per share Segments and geographic information Segment Reporting Disclosure [Text Block] Segments and geographic information Use of Estimates, Policy [Policy Text Block] Use of estimates Disclosure of policy for significant risks and uncertainties. Significant Risks And Uncertainties Policy Text Block Significant risks and uncertainties Disclosure of accounting policy for unaudited interim financial information. Unaudited Interim Financial Information [Policy Text Block] Unaudited interim financial information Disclosure of accounting policy Research and development incentives and receivable. Research And Development Incentives And Receivable [Policy Text Block] Research and development incentives and receivable New Accounting Pronouncements, Policy [Policy Text Block] Recently issued accounting pronouncements not yet adopted Property, Plant and Equipment [Table Text Block] Schedule of property and equipment, net Tabular disclosure of accrued expenses and other current liabilities. Accrued Liabilities and Other Current Liabilities [Table Text Block] Schedule of accrued expenses and other current liabilities Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share-based compensation. Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Schedule of share based compensation expense Share-Based Payment Arrangement, Option, Activity [Table Text Block] Schedule of share option activity Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of assumptions used to determine the fair value of share options granted Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Summarizes activity for RSUs under the 2020 Plan Collaborative Arrangement and Arrangement Other than Collaborative [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Represents information pertaining to Bayer collaboration agreements. Bayer Bayer Collaboration Agreement Bayer collaboration deferred revenue Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Significant agreements. Collaborative Arrangement and Arrangement Other than Collaborative [Table Text Block] Summary of revenue recognized from collaboration arrangements Represents the tabular disclosure of allocation of transaction price to separate performance obligations. Revenue, Performance Obligation, Allocation Of Transaction Price [Table Text Block] Summary of allocation of transaction price to separate performance obligations Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Summary of changes in the balances of the Company's contract assets and liabilities Represents the tabular disclosure of recognition of revenues as a result of changes in contract asset and contract liability balances. Revenue, Change In Contract with Customer, Asset and Liability [Table Text Block] Summary of recognition of revenues as a result of changes in contract asset and contract liability balances Lease, Cost [Table Text Block] Schedule of components of lease expense Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Schedule of maturities of operating lease liabilities Finance Lease, Liability, to be Paid, Maturity [Table Text Block] Schedule of maturities of finance lease liabilities Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of basic and diluted net loss attributable to ordinary shareholders Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Schedule of antidilutive securities excluded from computation of diluted net loss per share Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of company's single operating segment including significant segment expenses Long-Lived Assets by Geographic Areas [Table Text Block] Schedule of long-lived assets, including operating lease right-of-use assets, held in different geographic regions Scenario [Axis] Scenario [Domain] Represents the information pertaining to certain expenditure qualified as research and development intensive under RDEC scheme. Expenditure Qualified As Research and Development Intensive [Member] Expenditure qualified as research and development intensive Represents the information pertaining to certain expenditure not qualified as research and development intensive under RDEC scheme. Expenditure Not Qualified As Research and Development Intensive [Member] Expenditure not qualified as research and development intensive Research and Development Expense [Abstract] Research and development incentives and receivable Research and development: Percentage of tax credit on surrenderable trading losses that arise from qualifying research and development expenses incurred by the Company's subsidiaries in the United Kingdom. Research and Development Tax Reliefs Program, Percentage Of Tax Credit on Surrenderable Losses Percentage of surrenderable losses Percentage of tax credit on total expenditure during the period that arise from qualifying research and development expenses incurred by the Company's subsidiaries in the United Kingdom. Research and Development, Percentage Of Tax Credit on Total Expenditure Percentage of total expenditure Percentage of tax credit on total expenditure during the period that arise from qualifying research and development expenses incurred by the Company's subsidiaries in the United Kingdom for non research and development intensive entity. Research and Development, Percentage Of Tax Credit on Total Expenditure For Non Research And Development Intensive Entity Percentage of total expenditure for Non research and development intensive entity Amount of reduction of research and development expense. Reduction Of Research And Development Expense Reduction of research and development Fair Value, Recurring and Nonrecurring [Table] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 [Member] Level 1 Measurement Frequency [Axis] Measurement Frequency [Domain] Fair Value, Recurring [Member] Recurring Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Domain] Cash Equivalents [Member] Cash equivalents Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair value of financial assets and liabilities Money Market Funds, at Carrying Value Market funds Restricted Cash Collateral restricted cash Restricted Cash, Statement of Financial Position [Extensible Enumeration] Financial Liabilities Fair Value Disclosure Liabilities at fair value Assets, Fair Value Disclosure Assets at fair value Property, Plant and Equipment [Table] Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Domain] Equipment [Member] Laboratory equipment Leasehold Improvements [Member] Leasehold improvements Computer Equipment [Member] Computer equipment and software Furniture and Fixtures [Member] Furniture and office equipment Property, Plant and Equipment [Line Items] Property and equipment, net Property, Plant and Equipment, Gross Property and equipment Finance Lease, Right-of-Use Asset, before Accumulated Amortization Finance lease right-of-use assets Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Property and equipment, gross Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization Less: Accumulated depreciation and amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Property and equipment, net Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization expense Finance Lease, Right-of-Use Asset, Amortization Amortization expense of property and equipment under finance leases Amortization of finance lease right-of-use assets Employee-related Liabilities, Current Accrued employee compensation and benefits Carrying value as of the balance sheet date of obligations incurred through and payable for external research and development expenses. Accrued External Research and Development Expenses Accrued external research and development expenses Accrued Professional Fees, Current Accrued professional fees Operating Lease, Liability, Current Less: current lease liabilities Current portion of operating lease liabilities Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Current Less: current lease liabilities Current portion of finance lease liabilities Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Liabilities, Current Other Restructuring Cost [Table] Accrued expenses and other current liabilities Restructuring Plan [Axis] Restructuring Plan [Domain] Represents information pertaining to strategic reprioritization of clinical portfolio. Strategic Reprioritization Of Clinical Portfolio [Member] Strategic reprioritization of clinical portfolio Represents information pertaining to cost reduction initiatives. Cost Reduction Initiatives [Member] Cost reduction initiatives Statement of Income Location, Balance [Axis] Statement of Income Location, Balance [Domain] Research and Development Expense [Member] Research and development expenses General and Administrative Expense [Member] General and administrative expenses Restructuring Cost and Reserve [Line Items] Accrued expenses and other current liabilities Restructuring and Related Cost, Number of Positions Eliminated, Period Percent Percentage of workforce reduction Restructuring and Related Cost, Expected Cost Cash expenditure for severance and other employee termination benefits Restructuring and Related Cost, Incurred Cost Recognized charges Restructuring Charges Restructuring charges Payments for Restructuring Payments for restructuring Amount of contract termination costs incurred during the period. Contract Termination Costs Contract termination costs Restructuring Reserve, Current Accrued restructuring costs Stock, Class of Stock [Table] Represents information pertaining to voting ordinary shares. Voting ordinary shares Voting ordinary shares Class of Stock [Line Items] Ordinary shares Number of vote per share. Number of Vote Per Share Vote per ordinary share Common Stock, Dividends, Per Share, Declared Dividends declared Plan Name [Axis] Plan Name [Domain] Represents information pertaining to 2024 Inducement Plan. Inducement Plan, 2024 [Member] 2024 Inducement Plan This member represents 2020 share option plan. 2020 Plan 2020 Plan This member represents 2019 share option plan. 2019 Plan 2019 Plan Statistical Measurement [Axis] Statistical Measurement [Domain] Minimum [Member] Minimum Maximum [Member] Maximum Share-Based Payment Arrangement [Member] Stock option Share-based payment arrangement in which award of equity shares are granted with three year vesting period. Share-Based Payment Arrangement Three Year Vest [Member] Stock option three year vest Restricted Stock [Member] Restricted share units RSUs Employee Stock [Member] Employee Share Purchase Plan Grantee Status [Axis] Grantee Status [Domain] Share-Based Payment Arrangement, Employee [Member] Employee Share-Based Payment Arrangement, Nonemployee [Member] Non-employee Vesting [Axis] Vesting [Domain] Share-Based Payment Arrangement, Tranche One [Member] First anniversary Share-Based Payment Arrangement, Tranche Two [Member] Remaining equal installments Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period Contractual life Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Vesting period Represents the number of equal monthly installments for remaining awards. Share Based Compensation Arrangements By Share Based Payment, Award Vesting, Number Of Equal Monthly Installments Number of equal monthly installments for vesting remaining awards Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Number of ordinary shares reserved for issuance Common Stock, Capital Shares Reserved for Future Issuance Number of shares reserved for issuance Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Outstanding number of shares at end Outstanding number of shares at beginning Shares outstanding Percentage of annual increase in reserves on total number of ordinary shares outstanding. Share Based Compensation Arrangement By Share Based Payment Award Annual Increase Percentage Percentage of annual increase in reserves on total number of ordinary shares outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized Increase in number of ordinary shares reserved for future issuance Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Number of shares available for issuance Represents the number of equal annual installments for remaining awards. Share Based Compensation Arrangements By Share Based Payment, Award Vesting, Number Of Equal Annual Installments Number of equal annual installments Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage Vesting Percentage Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period Unrecognized compensation cost expected to be recognized over a weighted average period Service period Represents the number of equal quarterly installments for remaining awards. Share Based Compensation Arrangements By Share Based Payment, Award Vesting, Number Of Equal Quarterly Installments Number of equal quarterly installments for vesting remaining awards Number of shares issued upon conversion of restricted share units under share based compensation arrangement. Share Based Compensation Arrangement By Share Based Payment Awards, Share Conversion Ratio Right to receive upon vesting This is representing number of quarterly installments. Number Of Quarterly Installments Number of quarterly installments Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Share-based compensation. Share-Based Payment Arrangement, Expense Total share-based compensation expense Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Forfeited Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Number of shares, vested and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Number of shares, options exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted average exercise price at ending Weighted average exercise price at beginning Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Granted Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Exercised Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Forfeited Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Weighted average exercise price, vested and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted average exercise price, options exercisable No definition Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Contractual Term [Abstract] Weighted Average Contractual Term Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted average contractual term, outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Weighted average contractual term, vested and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Weighted average contractual term ,options exercisable No definition Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Aggregate Intrinsic Value [Abstract] Aggregate Intrinsic Value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Aggregate intrinsic value outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Aggregate intrinsic value, vested and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Aggregate intrinsic value, options exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Additional Information Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Granted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Exercised Title and Position [Axis] Title and Position [Domain] Represents information pertaining to employee and director. Employees and directors Employees and directors Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Risk-free interest rate Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected volatility Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Expected term (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount [Abstract] Unrecognized compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Total unrecognized compensation expense related to the unvested employee and director Unrecognized compensation cost Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Number of Shares Underlying RSUs Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Unvested restricted ordinary shares at ending Unvested restricted ordinary shares at beginning Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Granted The number of equity-based payment instruments, excluding stock (or unit) options, that vested and settled during the reporting period. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested And Settled in Period Vested and settled The number of equity-based payment instruments, excluding stock (or unit) options, that vested and deferred during the reporting period. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested And Deferred in Period Vested and deferred Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Forfeited The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period, subject to deferred settlement. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Subject to Deferred Settlement Vested but subject to deferred settlement at ending Vested but subject to deferred settlement at beginning The number of vested and non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Outstanding, Number Outstanding restricted ordinary shares at ending Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted average grant date fair value unvested, Ending Balance Weighted average grant date fair value unvested, Beginning Balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Granted The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee vested and settled during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested And Settled in Period, Weighted Average Grant Date Fair Value Vested and settled The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee vested and deferred during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested And Deferred in Period, Weighted Average Grant Date Fair Value Vested and deferred Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Forfeited The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right, subject to deferred settlement during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Subject To Deferred Settlement, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Vested but subject to deferred settlement, ending Weighted average grant date fair value, Vested but subject to deferred settlement, beginning Per share or unit weighted-average fair value of vested and nonvested award under share-based payment arrangement. Excludes share and unit options. Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Grant Date Fair Value Weighted average grant date fair value, Outstanding at Ending Balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Restricted shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Fair value of employee restricted share awards vested Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Weighted average period Represents the information pertaining to Novartis Collaboration Agreement. Novartis Novartis Novartis collaboration deferred revenue Represents information pertaining to the Genentech collaboration agreement. Genentech Genentech collaboration deferred revenue Number of collaboration targets under the collaboration agreement. Collaboration Agreement , Number of Targets Number of collaboration targets Represents period over which performance obligations will be performed. Period Over Which Performance Obligations Will Be Performed Expected period for satisfaction of performance obligations The duration of material rights exercised or expired. Material Rights Exercise or Expiry Term Material rights exercise period Contract with Customer, Liability Ending Balance Beginning Balance Deferred revenue Deferred revenue Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Represents information pertaining to Two combined performance obligations related to the licenses and research and development services associated with radiopharmaceutical compounds directed to the first and second targets. Two combined performance obligations related to the licenses and research and development services associated with radiopharmaceutical compounds directed to the first and second targets [Member] Combined performance obligation related to the licenses and research and development services associated with radiopharmaceutical compounds directed to the remaining initial target Represents information pertaining to material right associated with limited substitution rights for either the first or second target. Material right associated with limited substitution rights for either the first or second target [Member] Material right associated with limited substitution rights for the remaining initial target Represents information pertaining to two material rights associated with the option to progress radiopharmaceutical candidates directed to the first and second targets into further development. Two material rights associated with the option to progress radiopharmaceutical candidates directed to the first and second targets into further development [Member] Material right associated with the option to progress radiopharmaceutical candidates directed to the remaining initial target into further development Represents information pertaining to two material rights associated with the option to progress a non-radiopharmaceutical compound directed to the first and second targets. Two material rights associated with the option to progress a non-radiopharmaceutical compound directed to the first and second targets [Member] Material right associated with the option to progress a non-radiopharmaceutical compound directed to the remaining initial target Represents information pertaining to material right for the option to expand the collaboration to include a third target and the underlying additional option rights. Material right for the option to expand the collaboration to include a third target and the underlying additional option rights [Member] Material right for the option to expand the collaboration to include an additional target and the underlying additional option rights Amount of allocated determined transaction price under revenue recognition arrangement. Revenue Recognition, Allocated Determined Transaction Price Transaction price Represents the threshold period of notice required for termination of agreement. Collaborative Arrangement, Notice Required For Termination Of Agreement Threshold period of notice required for termination of agreement Represents the information pertaining to Ionis Collaboration Agreement. Ionis Ionis collaboration deferred revenue Represents information pertaining to Collaboration 4 performance obligation. Collaboration Program 4 Performance Obligation Number of Potential development candidates. Number Of Potential Development Candidates Number of potential development candidates Contract with Customer, Liability, Revenue Recognized Revenue recognized Indefinite-Lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Represents deferred revenue allocated to material rights that will commence revenue recognition when the respective option is exercised or when the option expires. Deferred revenue material rights option Change in Contract with Customer, Liability [Abstract] Contract liabilities: Amount of increase in contract with customer, liability. Contract with Customer, Liability, Additions Additions Amount of decrease in contract with customer, liability. Contract with Customer, Liability, Deductions Deductions Amount of adjustment in contract with customer, liability due to change in foreign exchange. Contract with Customer, Liability, Foreign Currency Adjustment Impact of Exchange Rates Change in Contract with Customer, Asset [Abstract] Contract assets Contract with Customer, Asset, after Allowance for Credit Loss, Current Contract assets Amount of revenue recognized based on proportional performance that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Contract with Customer, Liability, Revenue Recognized, Proportional Performance Obligation Revenue recognized based on proportional performance Amount of revenue recognized based on contract modifications and expiration of material rights that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Contract with Customer, Liability, Revenue Recognized, Contract Modifications And Expiration of Material Rights Revenue recognized based on contract modifications and expiration of material rights Amount of revenue recognized from both the beginning balance and current period increase in contract liability. Total Revenue Recognized From Both The Beginning Balance And Current Period Increase In Contract Liability Total Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Line Items] Income taxes. Lessee, Lease, Description [Table] Information by type of long-lived, physical assets used to produce goods and services and not intended for resale related to office and laboratory space in Cambridge, Massachusetts. Office and laboratory space in Cambridge Massachusetts Represents the information pertaining to lease agreement for new office and laboratory space in Cambridge, U.K. New Office and laboratory space in Cambridge, United Kingdom [Member] New Office and laboratory space in Cambridge, United Kingdom Lessee, Lease, Description [Line Items] Leases Total contractual term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Lessee, Operating Lease, Contractual Term Lease total contractual Term Lessee, Operating Lease, Term of Contract Leases, term of contract Period during which the company can occupy the lease space without paying rent, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Lease, Rent Free Period Rent-free period Lessee, Operating Lease, Renewal Term Renewal term Finance Lease, Right-of-Use Asset, after Accumulated Amortization Finance lease right-of-use assets Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability Finance lease liabilities Total lease liabilities Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration] Lessee, Finance Lease, Lease Not yet Commenced, Term of Contract Finance lease not yet commenced Unrecorded Unconditional Purchase Obligation Finance lease not yet commenced, contractual payments commitment Operating Lease, Cost Operating lease cost Variable Lease, Cost Variable lease cost Lessee, Finance Lease, Description [Abstract] Finance lease cost: Finance Lease, Interest Expense Interest on finance lease liabilities Amount of lease cost incurred by the lessee over the term of finance lease. Finance Lease, Cost Total finance lease cost Operating Lease, Weighted Average Remaining Lease Term Weighted-average remaining operating lease term (years) Operating Lease, Weighted Average Discount Rate, Percent Weighted average operating lease discount rate Finance Lease, Weighted Average Remaining Lease Term Weighted average remaining finance lease term (years) Finance Lease, Weighted Average Discount Rate, Percent Weighted average finance lease discount rate Represents information pertaining to agreement with third party. Agreement With Third Party Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Operating Leases Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year 2026 Lessee, Operating Lease, Liability, to be Paid, Year One 2027 Lessee, Operating Lease, Liability, to be Paid, Year Two 2028 Lessee, Operating Lease, Liability, to be Paid, Year Three 2029 Lessee, Operating Lease, Liability, to be Paid, Year Four 2030 Lessee, Operating Lease, Liability, to be Paid, Year Five 2031 Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value adjustment Operating Lease, Liability Total lease liabilities Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Finance Leases Finance Lease, Liability, to be Paid, Remainder of Fiscal Year 2026 Finance Lease, Liability, to be Paid, Year One 2027 Finance Lease, Liability, to be Paid, Year Two 2028 Finance Lease, Liability, to be Paid, Year Three 2029 Finance Lease, Liability, Undiscounted Excess Amount Present value adjustment Finance Lease, Liability, Noncurrent Long term lease liabilities Maximum days allowed for cancellation of contracts prior written notice, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Maximum Days Allowed for Cancellation of Contracts Prior Written Notice Maximum days allowed for cancellation of contracts prior written notice Amount of future milestone payment payable upon the achievement of development, regulatory and commercial milestones, Collaboration Agreement Future Milestone Contingent Payments Payable Future milestone payment payable Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Numerator: Net Income (Loss) Available to Common Stockholders, Basic Net loss Weighted Average Number of Shares Outstanding, Diluted [Abstract] Denominator: Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Options to purchase ordinary shares Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive securities Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive securities (in shares) Schedule of Revenues from External Customers and Long-Lived Assets [Table] Geographical [Axis] Geographical [Domain] UNITED STATES United States UNITED KINGDOM United Kingdom Revenues from External Customers and Long-Lived Assets [Line Items] Segments and geographic information Number of Operating Segments Number of operating segments Number of Reportable Segments Number of reportable segments Long-Lived Assets Long lived assets, including operating lease right of use assets Represents the number of geographic regions in which the entity operates. Number Of Geographic Regions In Which Operating Number of geographic regions Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Domain] Represents information pertaining to single reportable segment. Single Reportable Segment [Member] Single reportable segment Project [Axis] Project [Domain] Represents information pertaining to internal program for clinical trial of product candidate, a Bicycle Toxin Conjugate molecule BT8009 for tumors. Internal Program, Product Candidate, Bicycle Toxin Conjugate Molecule, B T 8009 [Member] Zelenectide pevedotin (Nectin-4 BDC) Represents information pertaining to internal program for clinical trial of product candidate, a Bicycle Toxin Conjugate molecule BT5528 for tumors. Internal Program, Product Candidate, Bicycle Toxin Conjugate Molecule, B T 5528 [Member] Nuzefatide pevedotin (EphA2 BDC) Represents information pertaining to internal program for clinical trial of product candidate, a Bicycle Radioconjugate B T 1702. Internal Program, Product Candidate, Bicycle Radioconjugate, B T 1702 [Member] BT1702 (MT1-MMP BRC) Represents information pertaining to internal program for clinical trial of Bicycle tumor-targeted immune cell agonists molecule, a BT7480 for immune. Internal Program, Bicycle Tumor-Targeted Immune Cell Agonists, B T 7480 [Member] Bicycle tumor-targeted immune cell agonists Segment Reporting Information [Line Items] Segments and geographic information Amount of cost incurred for specific project including but not limited to its clinical trials, program related costs and registration trails etc. Project Specific Costs Project specific costs Amount of expenses for discovery, platform and other pursuant to research and development activities. Research And Development, Discovery, Platform And Other expenses Discovery, platform and other expense Amount of expense for salary, wage, profit sharing and other employee benefit and contractor related expenses pursuant to research and development activities. Research And Development, Employee And Contractor Related Expenses Employee and contractor related expenses Amount of expense for award under share-based payment arrangement. Excludes amount capitalized, allocated to research and development activities. Research And Development, Share Based Payment Arrangement Expense Share-based compensation Amount of expenses for utilizing the facility for clinical trials categorized as research and development activities. Facility Expenses Facility expenses Amount of income recognized relating to tax credits, incentives and grants from government relating to research and development of the company. Research And Development, Tax Credits, Incentives And Government Grants Research and development incentives and government grants General and Administrative Expense [Abstract] General and administrative: Labor and Related Expense Personnel-related costs Professional Fees Professional and consulting fees Other General and Administrative Expense Other general and administrative costs Amount of expense for award under share-based payment arrangement. Excludes amount capitalized, allocated to general and administration activities of the company as a whole. General And Administrative, Share Based Payment Arrangement, Expense Share-based compensation Gain (Loss), Foreign Currency Transaction, before Tax Effect of foreign exchange rates Segment Reporting, Other Segment Item, Amount Other segment items Segment Reporting, Other Segment Item, Composition, Description