Entity Central Index Key Cover [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Well-known Seasoned Issuer Entity Well Known Seasoned Issuer Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company ICFR Auditor Attestation Flag Icfr Auditor Attestation Flag Entity Shell Company Entity Shell Company Entity Tax Identification Number Entity Tax Identification Number Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Public Float Entity Public Float Title of 12(b) Security Security12b Title Security Exchange Name Security Exchange Name Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Entity Address, Address Line One Entity Address Address Line1 Entity Address, Address Line Two Entity Address Address Line2 Entity Address, City or Town Entity Address City Or Town Entity Address, Country Entity Address Country Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Document Annual Report Document Annual Report Document Transition Report Document Transition Report Auditor Firm ID Auditor Firm Id Auditor Name Auditor Name Auditor Location Auditor Location Statement Of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Current portion of accounts receivable Accounts Receivable Net Current Prepaid expenses Prepaid Expense Current Other current assets Other Assets Current Total current assets Assets Current Long-term assets: Assets Noncurrent [Abstract] Property and equipment, net Property Plant And Equipment Net Operating lease right-of-use assets Operating Lease Right Of Use Asset Restricted cash Restricted Cash And Cash Equivalents Noncurrent Other assets Other Assets Total long-term assets Assets Noncurrent Total assets Assets Liabilities, Series A preferred shares and shareholders’ equity Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued expenses and other current liabilities Accrued Liabilities And Other Liabilities Current portion of deferred revenue Contract With Customer Liability Current Current portion of operating lease liability Operating Lease Liability Current Total current liabilities Liabilities Current Long-term liabilities: Liabilities Noncurrent [Abstract] Deferred revenue, net of current portion Contract With Customer Liability Noncurrent Operating lease liability, net of current portion Operating Lease Liability Noncurrent Other liabilities Other Liabilities Noncurrent Total long-term liabilities Liabilities Noncurrent Total liabilities Liabilities Series A preferred shares, no par value; 3,901,348 shares issued and outstanding at December 31, 2021 and 2020 Temporary Equity Carrying Amount Attributable To Parent Shareholders’ equity: Stockholders Equity [Abstract] Ordinary shares, no par value; 59,841,116 and 48,778,678 shares issued and outstanding at December 31, 2021 and 2020, respectively Common Stock Value Additional paid-in capital Additional Paid In Capital Accumulated other comprehensive income Accumulated Other Comprehensive Income Loss Net Of Tax Accumulated deficit Retained Earnings Accumulated Deficit Total shareholders’ equity Stockholders Equity Total liabilities, Series A preferred shares and shareholders’ equity Liabilities And Stockholders Equity Series A preferred stock, par value Temporary Equity Par Or Stated Value Per Share Series A preferred stock, shares issued Temporary Equity Shares Issued Series A preferred stock, shares outstanding Temporary Equity Shares Outstanding Common stock, par value Common Stock No Par Value Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Income Statement [Abstract] Revenue Revenue From Contract With Customer Excluding Assessed Tax Operating expenses: Operating Expenses [Abstract] Research and development Research And Development Expense General and administrative General And Administrative Expense Total operating expenses Operating Expenses Loss from operations Operating Income Loss Other income, net: Nonoperating Income Expense [Abstract] Dividend income and interest income, net Investment Income Interest And Dividend Other income, net Other Nonoperating Income Expense Total other income, net Nonoperating Income Expense Loss before income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Income tax benefit Income Tax Expense Benefit Net loss Net Income Loss Net loss per share attributable to ordinary shareholders—basic and diluted Earnings Per Share Basic And Diluted Weighted-average ordinary shares used in computing net loss per share attributable to ordinary shareholders—basic and diluted Weighted Average Number Of Share Outstanding Basic And Diluted Other comprehensive income (loss): Other Comprehensive Income Loss Net Of Tax Period Increase Decrease [Abstract] Net loss Foreign currency translation Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax Comprehensive loss Comprehensive Income Net Of Tax Stock issued during period shares restricted stock award vested. Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Ordinary Shares [Member] Common Stock [Member] Additional Paid-In-Capital [Member] Additional Paid In Capital [Member] Accumulated Other Comprehensive Income (Loss) [Member] Accumulated Other Comprehensive Income [Member] Accumulated Deficit [Member] Retained Earnings [Member] Class of Stock Statement Class Of Stock [Axis] Class of Stock Class Of Stock [Domain] Series A Preferred Shares [Member] Series A Preferred Stock [Member] Sale of Stock Subsidiary Sale Of Stock [Axis] Sale of Stock Sale Of Stock Name Of Transaction [Domain] At-the-market equity program. At-The-Market Equity Program [Member]​ At The Market Equity Program [Member] Statement [Line Items] Statement [Line Items] Beginning balance Beginning balance, shares Shares Outstanding Temporary equity, Beginning balance Temporary equity, Beginning balance, shares Issuance of ordinary shares Stock Issued During Period Value New Issues Issuance of ordinary shares, shares Stock Issued During Period Shares New Issues Share-based compensation Stock Issued During Period Value Share Based Compensation Gross Vesting of RSUs, shares Stock Issued During Period Shares Restricted Stock Award Vested Option exercises Stock Issued During Period Value Stock Options Exercised Option exercises, shares Stock Issued During Period Shares Stock Options Exercised Issuance of ordinary shares under the ESPP Stock Issued During Period Value Employee Stock Purchase Plan Issuance of ordinary shares under ESPP, shares Stock Issued During Period Shares Employee Stock Purchase Plans Other comprehensive income (loss) Other Comprehensive Income Loss Net Of Tax Ending balance Ending balance, shares Temporary equity, Ending balance Temporary equity, Ending balance, shares Amortization of right-of-use assets. Increase (decrease) in Operating lease liabilities. Statement Of Cash Flows [Abstract] Cash flows from operating activities Net Cash Provided By Used In Operating Activities [Abstract] Net loss Profit Loss Adjustments to reconcile net loss to net cash used in operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Amortization of right-of-use assets Amortization Of Right Of Use Assets Depreciation of property and equipment Depreciation Share-based compensation expense Allocated Share Based Compensation Expense Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Accounts receivable Increase Decrease In Accounts Receivable Prepaid expenses Increase Decrease In Prepaid Expense Other assets Increase Decrease In Other Operating Assets Accounts payable Increase Decrease In Accounts Payable Accrued expenses and other current liabilities Increase Decrease In Accrued Liabilities And Other Operating Liabilities Deferred revenue Increase Decrease In Contract With Customer Liability Operating lease liabilities Increase Decrease In Operating Lease Liabilities Other non-current liabilities Increase Decrease In Other Noncurrent Liabilities Net cash used in operating activities Net Cash Provided By Used In Operating Activities Cash flows from investing activities Net Cash Provided By Used In Investing Activities [Abstract] Purchases of property and equipment Payments To Acquire Property Plant And Equipment Net cash used in investing activities Net Cash Provided By Used In Investing Activities Cash flows from financing activities Net Cash Provided By Used In Financing Activities [Abstract] Proceeds from issuance of ordinary shares, net of offering costs Proceeds From Issuance Of Common Stock Proceeds from the exercise of share options Proceeds From Stock Options Exercised Proceeds from the ESPP Proceeds From Stock Plans Net cash provided by financing activities Net Cash Provided By Used In Financing Activities Effect of foreign exchange rates on cash Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Net increase (decrease) in cash, cash equivalents and restricted cash Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash, cash equivalents and restricted cash, beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Cash, cash equivalents and restricted cash, end of period Supplemental disclosure of cash flow information: Supplemental Cash Flow Elements [Abstract] Increase in operating lease right-of-use assets and lease liabilities related to new lease Right Of Use Asset Obtained In Exchange For Operating Lease Liability Documents Incorporated by Reference Documents Incorporated By Reference [Text Block] Organization Consolidation And Presentation Of Financial Statements [Abstract] The Company Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Accounting Policies [Abstract] Significant Accounting Policies Significant Accounting Policies [Text Block] Property Plant And Equipment [Abstract] Property and Equipment, Net Property Plant And Equipment Disclosure [Text Block] Payables And Accruals [Abstract] Accrued Expenses and Other Current Liabilities Accounts Payable Accrued Liabilities And Other Liabilities Disclosure Current [Text Block] Collaboration Agreements Collaborative Arrangement Disclosure [Text Block] Equity [Abstract] Share Capital Stockholders Equity Note Disclosure [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Share-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Leases [Abstract] Leases Lessee Operating Leases [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Earnings Per Share [Abstract] Net Loss Per Ordinary Share Earnings Per Share [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Postemployment Benefits [Abstract] Employee Benefit Plans Compensation And Employee Benefit Plans [Text Block] Related Party Transactions [Abstract] Related Parties Related Party Transactions Disclosure [Text Block] Cash Equivalents Cash And Cash Equivalents Policy [Text Block] Principles of Consolidation Consolidation Policy [Text Block] Use of Estimates Use Of Estimates Segment Data Segment Reporting Policy Policy [Text Block] Going concern. Going Concern Going Concern Policy [Text Block] Foreign Currency Translation Foreign Currency Transactions And Translations Policy [Text Block] Fair Value of Financial Instruments Fair Value Of Financial Instruments Policy Concentration of Credit Risk Concentration Risk Credit Risk Restricted Cash Cash And Cash Equivalents Restricted Cash And Cash Equivalents Policy Property and Equipment Property Plant And Equipment Policy [Text Block] Impairment of Long-Lived Assets Impairment Or Disposal Of Long Lived Assets Including Intangible Assets Policy Policy [Text Block] Revenue Recognition Revenue From Contract With Customer Policy [Text Block] Research and Development Expenses Research And Development Expense Policy Revenue from contract with customer license agreements and patent costs. License Agreements and Patent Costs Revenue From Contract With Customer License Agreements And Patent Costs Policy [Text Block] Refundable tax credits. Refundable Tax Credits Refundable Tax Credits Policy [Text Block] Net Loss per Share Earnings Per Share Policy [Text Block] Share-Based Compensation Share Based Compensation Option And Incentive Plans Policy Income Taxes Income Tax Policy [Text Block] Leases Lessee Leases Policy [Text Block] Recently Adopted Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Property Plant And Equipment Estimated Useful Lives Table [Text Block] Schedule of Estimated Useful Life of Assets Property Plant And Equipment Estimated Useful Lives Table [Text Block] Schedule of Property and Equipment, Net Property Plant And Equipment [Text Block] Summary of Accrued Expenses and Other Current Liabilities Schedule Of Accrued Liabilities Table [Text Block] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Award Type Award Type [Axis] Award Type Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Employee Stock Option [Member] Employee Stock Option [Member] Share-based Compensation Arrangement By Share-based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Summary of Share Option Activity Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Summary of Fair Value of Share Options Granted Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block] Summary of RSU Activity Schedule Of Share Based Compensation Restricted Stock Units Award Activity Table [Text Block] Summary of Share-based Compensation Expense Classified in Consolidated Statements of Operations and Comprehensive Loss Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Summary of Lease Costs Recognized and Other Information Pertaining to Operating Leases Lease Cost Table [Text Block] Schedule of Future Minimum Rental Payments for Operating Leases Under Topic 842 Lessee Operating Lease Liability Maturity Table [Text Block] Summary of Basic and Diluted Net Loss Per Ordinary Share Outstanding Schedule Of Earnings Per Share Basic And Diluted Table [Text Block] Anti-Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Ordinary Share Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] Singapore [Member] SINGAPORE Components of Loss before Income Taxes Schedule Of Income Before Income Tax Domestic And Foreign Table [Text Block] Deferred Components of Benefit (Provision), Net for Income Taxes Schedule Of Components Of Income Tax Expense Benefit Table [Text Block] Reconciliation of Statutory Income Tax Rate Schedule Of Effective Income Tax Rate Reconciliation Table [Text Block] Components of Deferred Tax Assets and Liabilities Schedule Of Deferred Tax Assets And Liabilities Table [Text Block] Summary of Valuation Allowance Summary Of Valuation Allowance [Text Block] Summary of Activity in Unrecognized Tax Benefits Summary Of Income Tax Contingencies [Text Block] Significant Accounting Policies [Line Items] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Cambridge MA. Cambridge MA [Member] Cambridge M A [Member] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Number of operating segment Number Of Operating Segments Cash, cash equivalents and restricted cash Schedule Of Property Plant And Equipment [Table] Schedule Of Property Plant And Equipment [Table] Long-Lived Tangible Asset Property Plant And Equipment By Type [Axis] Long-Lived Tangible Asset Property Plant And Equipment Type [Domain] Equipment, Furniture and Software. Equipment, Furniture and Software [Member] Equipment Furniture And Software [Member] Leasehold Improvements [Member] Leasehold Improvements [Member] Property Plant And Equipment [Line Items] Property Plant And Equipment [Line Items] Property and equipment, estimated useful lives Property Plant And Equipment Useful Life Property and equipment, estimated useful lives Property Plant And Equipment Estimated Useful Lives Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Start Date [Axis] Revenue recognition performance obligation, expected time satisfaction period Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 Revenue, practical expedient, incremental costs of obtaining contract Revenue Practical Expedient Incremental Cost Of Obtaining Contract Expected dividend rate Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate Income taxes examination likelihood of realization on settlement percentage. Description of Income tax benefit, likelihood of realized upon ultimate settlement Income Tax Examination Likelihood Of Unfavorable Settlement Income tax examination, likelihood of settlement, percentage Income Taxes Examination Likelihood Of Realization On Settlement Percentage Furniture and Equipment [Member] Furniture And Fixtures [Member] Software [Member] Software Development [Member] Fixed Assets in Progress [Member] Construction In Progress [Member] Property and equipment gross Property Plant And Equipment Gross Less accumulated depreciation Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Property and equipment, net Depreciation expense Accrued expenses and other current liabilities. Accrued compensation Employee Related Liabilities Current Accrued expenses related to CROs and CMOs Accrued Liabilities Current Accrued expenses and other current liabilities Accrued Expenses And Other Current Liabilities Total accrued expenses and other current liabilities Counterparty nominations number of research programs. Collaboration agreement upfront payment. Collaboration and Share Purchase Agreements [Abstract] Collaboration And Share Purchase Agreements [Abstract] Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Collaborative Arrangement and Arrangement Other than Collaborative Type Of Arrangement [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Arrangements And Nonarrangement Transactions [Member] Research, license and option agreement. Research, License and Option Agreement [Member] Research License And Option Agreement [Member] Counterparty Name Counterparty Name [Axis] Counterparty Name Repurchase Agreement Counterparty Name [Domain] Pfizer Inc. Pfizer Inc. [Member] Pfizer Inc [Member] Product and Service Product Or Service [Axis] Product and Service Products And Services [Domain] Research term. Research Term [Member] Research Terms [Member] Collaboration and license agreement. Collaboration And License Agreement [Member] Collaboration And License Agreement [Member] Takeda pharmaceutical company limited. Takeda [Member] Takeda Pharmaceutical Company Limited [Member] Collaboration and share purchase agreements. Collaboration and Share Purchase Agreements [Member] Collaboration And Share Purchase Agreements [Member] Category one programs. Category One Programs [Member] Category One Programs [Member] Category two programs. Category Two Programs [Member] Category Two Programs [Member] Category one programs and category two programs. Category 1 Programs and Category 2 Programs [Member] Category One Programs And Category Two Programs [Member] Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Number of research programs, counterparty nomination Counterparty Nominations Number Of Research Programs Upfront payment under collaboration agreement Collaboration Agreement Upfront Payment Shares issued under equity agreement Equity investment aggregate purchase price Purchase price per share Shares Issued Price Per Share Collaborative agreement research period. Research term description. Collaborative agreement research term Collaborative Agreement Research Period Research term, description Research Term Description Revenue recognized Contract With Customer Liability Revenue Recognized Collaboration and license agreement month and year. Fund receivable for research and preclinical activities. Collaboration and license agreement research term. Collaboration agreement committed cash. Collaboration and license agreement month and year Collaboration And License Agreement Month And Year Fund receivable for research and preclinical activities Fund Receivable For Research And Preclinical Activities Research term under collaboration and license agreement Collaboration And License Agreement Research Term Collaboration agreement, committed cash Collaboration Agreement Committed Cash Equity investment agreement official closure date month and year. Purchase price per share Sale Of Stock Price Per Share Equity investment agreement official closure month and year Equity Investment Agreement Official Closure Date Month And Year Percentage of global costs and potential profits sharing ratio. Percentage of global costs and potential profits sharing ratio Percentage Of Global Costs And Potential Profits Sharing Ratio Maximum targets for preclinical programs. Option to reach maximum targets for preclinical programs. Maximum targets for preclinical programs Maximum Targets For Preclinical Programs Option to reach maximum targets for preclinical programs Option To Reach Maximum Targets For Preclinical Programs Collaboration agreement commencement date. Collaboration agreement commencement date Collaboration Agreement Commencement Date Maximum termination notice period. Maximum Termination Notice Period Maximum Termination Notice Period Up-front consideration received. Up-front consideration received Up Front Consideration Received Collaboration and license agreement date. collaboration-budgeted research and preclinical expenses. Collaboration and License Agreement Date Collaboration And License Agreement Date Collaboration-budgeted research and preclinical expenses Collaboration Budgeted Research And Preclinical Expenses Collaboration revenue recognized Collaboration and license agreement, deferred revenue Contract With Customer Liability Collaboration and license agreement, deferred revenue current Collaboration and license agreement, deferred revenue noncurrent Gross proceeds from issuance of common stock. Schedule Of Stock By Class [Table] Schedule Of Stock By Class [Table] Follow-On Underwritten Public Offering [Member] I P O [Member] Class of Stock [Line Items] Class Of Stock [Line Items] Issue of ordinary shares, shares Gross proceeds from sale of ordinary shares Gross Proceeds From Issuance Of Common Stock Net proceeds from sale of ordinary shares Proceeds from issuance of common stock excluding unpaid offering expenses. Net proceeds from sale of ordinary shares after deducting commissions and offering expenses Proceeds From Issuance Of Common Stock Excluding Unpaid Offering Expenses Common stock, authorized Common Stock Shares Authorized Preferred stock, par value Preferred Stock No Par Value Preferred stock, shares authorized Preferred Stock Shares Authorized Common stock vote per share. Ordinary share holder, voting right Common Stock Voting Rights Voting rights, votes per share Common Stock Votes Per Share Preferred stock liquidation preference, per share Preferred Stock Liquidation Preference Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] 2021 equity incentive plan. 2021 Plan [Member] Two Thousand Twenty One Equity Incentive Plan [Member] Two thousand fourteen equity incentive plan. 2014 Plan [Member] Two Thousand Fourteen Equity Incentive Plan [Member] Options granted outside of 2014 plan as inducement grants. Options Granted Outside of 2014 Plan As Inducement Grants [Member] Options Granted Outside Of2014 Plan As Inducement Grants [Member] Title of Individual Title Of Individual [Axis] Title of Individual Title Of Individual With Relationship To Entity [Domain] Non employee. Non Employee [Member] Non Employee [Member] Time-based restricted stock units. Time-based RSUs [Member] Time Based Restricted Stock Units [Member] Performance based restricted stock units. Performance Based RSUs [Member] Performance Based Restricted Stock Units [Member] RSUs granted outside of 2014 plan as inducement grants. RSUs Granted Outside of 2014 Plan As Inducement Grants [Member] R S Us Granted Outside Of2014 Plan As Inducement Grants [Member] RSUs [Member] Restricted Stock Units R S U [Member] Employee share purchase plan. ESPP [Member] Employee Share Purchase Plan [Member] Ordinary shares authorized for issuance Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized Ordinary shares available for future grant Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Share Based Arrangements To Obtain Goods And Services [Abstract] Outstanding, Number of Shares, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Granted, Number of Shares Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Exercised, Number of Shares Forfeited or cancelled, Number of Shares Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period Outstanding, Number of Shares, Ending Balance Options exercisable, Number of Shares Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Outstanding, Weighted Average Exercise Price, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Granted, Weighted Average Exercise Price Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price Exercised, Weighted Average Exercise Price Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Forfeited or cancelled, Weighted Average Exercise Price Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price Outstanding, Weighted Average Exercise Price, Ending Balance Options exercisable, Weighted Average Exercise Price Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price Outstanding, Weighted Average Remaining Contractual Term Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 Options exercisable, Weighted Average Remaining Contractual Term Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 Outstanding, Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value Options exercisable, Aggregate Intrinsic Value Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 Vesting period Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 Contractual life of options Sharebased Compensation Arrangement By Sharebased Payment Award Expiration Period Options granted Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract] Risk-free interest rate, minimum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Minimum Risk-free interest rate, maximum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Maximum Expected term (in years) Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 Expected volatility, minimum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Minimum Expected volatility, maximum Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Maximum Expected dividend yield Outstanding, Number of Shares, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number Granted, Number of Shares Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Vested, Number of Shares Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Forfeited, Number of Shares Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period Outstanding, Number of Shares, Ending Balance Outstanding, Average Grant Date Fair Value, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value Granted, Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value Vested, Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value Forfeited, Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value Outstanding, Average Grant Date Fair Value, Ending Balance Shares granted to employees RSUs outstanding Unrecognized stock-based compensation expense Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options Unrecognized stock-based compensation weighted average recognition period Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 Weighted average grant date fair value per granted option Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value Aggregate fair value of options vested Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 Unrecognized stock-based compensation expense Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Share Based Awards Other Than Options Fair value of RSUs vested Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value Share purchase price at equal to fair market value percentage. Ordinary shares reserved for issuance Common Stock Capital Shares Reserved For Future Issuance Share purchase price at equal to fair market value percentage Share Purchase Price At Equal To Fair Market Value Percentage Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Research and Development Expenses [Member] Research And Development Expense [Member] General and Administrative Expenses [Member] General And Administrative Expense [Member] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Lessee leasing arrangements operating leases renewal term description. Schedule Of Operating Leased Assets [Table] Schedule Of Operating Leased Assets [Table] Lexington Massachusetts. Lexington, Massachusetts [Member] Lexington Massachusetts [Member] Cambridge, Massachusetts. Cambridge, Massachusetts [Member] Cambridge Massachusetts [Member] Operating Leased Assets [Line Items] Operating Leased Assets [Line Items] Lease agreement term Lessee Operating Lease Term Of Contract Renewal options Lessee Leasing Arrangements Operating Leases Renewal Term Description Restricted cash Lease renewal term Lessee Operating Lease Renewal Term Lease option to extend description Lessee Operating Lease Option To Extend Option to extend the lease Lessee Operating Lease Existence Of Option To Extend Description of additional lease space Lessee Operating Lease Description Operating lease liability Operating Lease Liability Increase in operating right-of-use assets. Other information pertaining to operating leases. Lease cost Lease Cost [Abstract] Operating lease cost Operating Lease Cost Variable lease cost Variable Lease Cost Total lease cost Lease Cost Other information Other Information Pertaining To Operating Leases [Abstract] Operating cash flows used for operating leases Operating Lease Payments Increase in operating right-of-use assets Increase In Operating Right Of Use Assets Operating lease liabilities arising from obtaining right-of-use assets Weighted average remaining lease term Operating Lease Weighted Average Remaining Lease Term1 Weighted average discount rate Operating Lease Weighted Average Discount Rate Percent Operating Lease Liabilities, Payments Due [Abstract] Operating Lease Liabilities Payments Due [Abstract] 2022 Lessee Operating Lease Liability Payments Due Next Twelve Months 2023 Lessee Operating Lease Liability Payments Due Year Two 2024 Lessee Operating Lease Liability Payments Due Year Three 2025 Lessee Operating Lease Liability Payments Due Year Four 2026 Lessee Operating Lease Liability Payments Due Year Five Thereafter Lessee Operating Lease Liability Payments Due After Year Five Total lease payments Lessee Operating Lease Liability Payments Due Less: imputed interest Lessee Operating Lease Liability Undiscounted Excess Amount Total operating lease liabilities Numerator: Net Income Loss [Abstract] Net loss attributable to ordinary shareholders Net Income Loss Available To Common Stockholders Basic Denominator: Weighted Average Number Of Shares Outstanding [Abstract] Weighted-average ordinary shares outstanding Net loss per share, basic and diluted Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Options to Purchase Ordinary Shares [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Anti-dilutive shares excluded from calculation of diluted net loss per share Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Income Taxes [Line Items] Income Taxes [Table] Income Taxes [Table] Income Taxes [Table] Rest of World. Rest Of World [Member] Rest Of World [Member] Income Taxes [Line Items] Income Taxes [Line Items] Loss before income taxes Income Tax Authority Income Tax Authority [Axis] Income Tax Authority Income Tax Authority [Domain] Federal [Member] Domestic Country [Member] State [Member] State And Local Jurisdiction [Member] Tax Credit Carryforward Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name Tax Credit Carryforward Name [Domain] Research and development tax credit carryforward. Research and development Research And Development Tax Credit Carryforward [Member] Orphan drug credits. Orphan Drug Credits [Member] Orphan Drug Credits [Member] Investment tax credit carryforward. Investment Investment Tax Credit Carryforward [Member] Japan [Member] JAPAN UK [Member] UNITED KINGDOM United States [Member] UNITED STATES Consolidated Entities Consolidated Entities [Axis] Consolidated Entities Consolidated Entities [Domain] Subsidiaries Outside of Singapore [Member] Subsidiaries [Member] Income tax benefit (provision) Current benefit, net for income taxes: Current Income Tax Expense Benefit Continuing Operations [Abstract] Total current benefit, net for income taxes Current Income Tax Expense Benefit Deferred benefit, net for income taxes: Deferred Income Tax Expense Benefit Continuing Operations [Abstract] Total deferred benefit, net for income taxes Deferred Income Tax Expense Benefit Total benefit, net for income taxes Effective Income Tax Rate Reconciliation Permanent Differences Effective income tax rate reconciliation change in reserve for uncertain tax positions. Schedule Of Effective Income Tax Rate Reconciliation [Table] Schedule Of Effective Income Tax Rate Reconciliation [Table] Schedule Of Effective Income Tax Rate Reconciliation [Table] Singapore statutory income tax rate Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate Federal and state tax credits Effective Income Tax Rate Reconciliation Tax Credits Permanent differences Effective Income Tax Rate Reconciliation Permanent Differences Changes in reserves for uncertain tax positions Effective Income Tax Rate Reconciliation Change In Reserve For Uncertain Tax Positions Foreign rate differential Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential Tax rate change Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate Other Effective Income Tax Rate Reconciliation Other Adjustments Change in deferred tax asset valuation allowance Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance Effective income tax rate Effective Income Tax Rate Continuing Operations Deferred tax assets tax deferred expense accumulated amortization. Deferred tax assets tax deferred expense operating lease liabilities. Deferred tax liabilities accumulated depreciation. Deferred tax assets: Deferred Tax Assets Net [Abstract] Net operating loss carryforwards Deferred Tax Assets Operating Loss Carryforwards Federal and state tax credits Deferred Tax Assets Tax Credit Carryforwards Share-based compensation Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost Accumulated amortization Deferred Tax Assets Tax Deferred Expense Accumulated Amortization Operating lease liabilities Deferred Tax Assets Tax Deferred Expense Operating Lease Liabilities Deferred revenue Deferred Tax Assets Deferred Income Other Deferred Tax Assets Other Total deferred tax assets Deferred Tax Assets Gross Valuation allowance Deferred Tax Assets Valuation Allowance Net deferred tax assets Deferred Tax Assets Net Deferred tax liabilities: Deferred Tax Liabilities Net [Abstract] Operating lease right-of-use assets Deferred Tax Liabilities Leasing Arrangements Accumulated depreciation Deferred Tax Liabilities Accumulated Depreciation Other Deferred Tax Liabilities Other Total deferred tax liabilities Deferred Income Tax Liabilities Net deferred tax assets (liabilities) Deferred Tax Assets Liabilities Net Deferred tax assets valuation allowance increase. Deferred tax assets valuation foreign currency translation. Deferred Tax Assets Net Of Valuation Allowance [Abstract] Balance at beginning of year Increase in valuation allowance Deferred Tax Assets Valuation Allowance Increase Effect of foreign currency translation Deferred Tax Assets Valuation Foreign Currency Translation Balance at end of year Research and development tax credit carryforward expiration year. Tax credit carry forward expiration year Operating Loss Carry forward expiration year. Investment tax credit carryforward expiration year. Net operating loss carryforwards Operating Loss Carryforwards Net operating loss carryforwards available to offset future income tax liabilities indefinitely Deferred Tax Assets Operating Loss Carryforwards Not Subject To Expiration Net operating loss carryforwards available to offset future income tax liabilities Deferred Tax Assets Operating Loss Carryforwards Subject To Expiration Operating Loss Carry forward expiration year Operating Loss Carry Forward Expiration Year Tax credit carryforward Tax Credit Carryforward Amount Research and development tax credit carryforward expiration year Research And Development Tax Credit Carryforward Expiration Year Investment tax credit carryforward expiration year Investment Tax Credit Carryforward Expiration Year U.S.Orphan drug credit carryforward expiration year Tax Credit Carry Forward Expiration Year Operating loss carryforwards expiration year. Net operating loss carryovers Operating loss carryforwards expiration year Operating Loss Carryforwards Expiration Year Increase in valuation allowance Valuation Allowance Deferred Tax Asset Change In Amount Unrecognized tax benefits increases (decreases) resulting from prior period tax positions. Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward Unrecognized tax benefit at the beginning of the year Unrecognized Tax Benefits Tax positions related to prior years Unrecognized Tax Benefits Increases Decreases Resulting From Prior Period Tax Positions Tax positions related to prior years Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions Tax positions related to statute lapse Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations Tax positions related to the current year Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions Unrecognized tax benefit at the end of the year Gross unrecognized tax benefit Unrecognized tax benefit that could affect annual effective tax rate if recognized Unrecognized Tax Benefits That Would Impact Effective Tax Rate Tax years open to examination Open Tax Year Cash held by subsidiaries Cash Compensation And Retirement Disclosure [Abstract] Defined Contribution Plan [Table] Defined Contribution Plan [Table] Four Zero One K Plan [Member] 401(k) Plan [Member] Four Zero One K Plan [Member] Defined Contribution Plan Disclosure [Line Items] Defined Contribution Plan Disclosure [Line Items] Discretionary contributions to defined contribution pension plan Defined Contribution Plan Employer Discretionary Contribution Amount Agreement termination notice period. Schedule Of Related Party Transactions By Related Party [Table] Schedule Of Related Party Transactions By Related Party [Table] Related Party Related Party Transactions By Related Party [Axis] Related Party Related Party [Domain] Scientific Advisor [Member] Scientific Advisor [Member] Scientific Advisor [Member] Related Party Transaction Related Party Transaction [Axis] Related Party Transaction Related Party Transaction [Domain] Consulting Agreement [Member] Consulting Agreement [Member] Consulting Agreement [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Consulting agreement termination notice period Agreement Termination Notice Period Consulting service expenses Professional And Contract Services Expense