Payment received Proceeds from Collaborators Reduction in carrying amount of right-of-use asset Operating Lease, Right-of-Use Asset, Periodic Reduction Summary of accrued liabilities Schedule of Accrued Liabilities [Table Text Block] Statistical Measurement Statistical Measurement [Domain] Total current assets Assets, Current Research and development Research and Development Expense Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax, Current Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax, Current Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Award Type Award Type [Domain] Research, development and commercial milestone payments Research Development And Commercial Milestone Payments [Member] Research, development and commercial milestone payments. Entity Filer Category Entity Filer Category Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Current Fiscal Year End Date Current Fiscal Year End Date Stock repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Performance-based RSUs Performance Shares [Member] Income Tax Authority Income Tax Authority [Axis] Accounts payable Accounts Payable, Current Computer equipment Computer Equipment [Member] Number of potential targets Number Of Potential Targets Number of potential targets. Corporate debt securities Corporate Debt Securities [Member] Total other income (expense), net Nonoperating Income (Expense) Preferred stock, shares authorized Preferred Stock, Shares Authorized Commitments and contingencies (see Note 11) Commitments and Contingencies Written notice period for termination of agreement Notice Period For Termination Of Agreement Notice period for termination of agreement. Preferred stock, shares outstanding Preferred Stock, Shares Outstanding MKDG Agreement MKDG Agreement [Member] MKDG Agreement Stockholder's equity Equity [Text Block] Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Proceeds from issuance of common stock Proceeds from Issuance of Common Stock Collaborative Arrangement and Arrangement Other than Collaborative Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Income taxes Income Tax Disclosure [Text Block] Stock Purchase Agreement Stock Purchase Agreement [Member] Stock Purchase Agreement Amount payable for extend research term option Amount Payable For Extend Research Term Option Amount payable for extend research term option. Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Marketable securities, current: Debt Securities, Available-for-sale, Current [Abstract] Debt Securities, Available-for-sale, Current Furniture and fixtures Furniture and Fixtures [Member] Current liabilities: Liabilities, Current [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Preferred stock, par value per share (in dollars per share) Preferred Stock, Par or Stated Value Per Share Total stockholders’ equity Beginning balance Ending balance Equity, Attributable to Parent Preferred stock, par value of $0.0001 per share; 10,000,000 shares authorized, and no shares issued or outstanding as of March 31, 2024 and December 31, 2023, respectively Preferred Stock, Value, Issued Additional upfront consideration received Additional Upfront Consideration Additional upfront consideration. Subsequent Event Type Subsequent Event Type [Domain] Nonrefundable upfront payment Non Refundable Upfront Payment Non refundable upfront payment. Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Net loss per share − diluted (in dollars per share) Earnings Per Share, Diluted Deferred revenue Increase (Decrease) in Deferred Revenue Leasehold improvements Leaseholds and Leasehold Improvements [Member] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule Of Property Plant And Equipment [Table] Property, Plant and Equipment [Table] Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Revenue recognized that was included in the contract liability at the beginning of the period Contract with Customer, Liability, Revenue Recognized Less: restricted cash Restricted Cash and Cash Equivalents Other (in shares) Adjustments To Additional Paid In Capital Other Shares Adjustments to additional paid in capital other shares. Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax, Noncurrent Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax, Noncurrent Level 3 Fair Value, Inputs, Level 3 [Member] Subsequent Events [Abstract] Loss before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Accrued compensation and benefits Accrued Employee Benefits, Current Marketable securities Fair Value Debt Securities, Available-for-Sale, Excluding Accrued Interest Issuance of common stock upon exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Trading Symbol Trading Symbol U.S. government debt securities US Government Agencies Debt Securities [Member] Restructuring Restructuring and Related Activities Disclosure [Text Block] Long-Lived Tangible Asset Long-Lived Tangible Asset [Axis] Preferred stock, shares issued Preferred Stock, Shares Issued Stock options granted, weighted average exercise price (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Stock options granted, weighted average grant date fair value (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Level 2 Fair Value, Inputs, Level 2 [Member] Net loss Net loss Net Income (Loss) Total current liabilities Liabilities, Current Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Research agreement, period Research And Development Agreement Period Research and development agreement period. Leases Lessee, Operating Leases [Text Block] Number of targeted protein degradation Number Of Targeted Protein Degradation Number of targeted protein degradation. Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Marketable securities, non-current: Debt Securities, Available-for-sale, Noncurrent [Abstract] Debt Securities, Available-for-sale, Noncurrent Amortization of debt discount − related party Amortization of Debt Discount (Premium) Stock repurchase program, premium percentage Stock Repurchase Program, Premium Percentage Stock Repurchase Program, Premium Percentage Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Transaction Price Unsatisfied Transaction Price Unsatisfied To Performance Obligation Transaction price unsatisfied to performance obligation. Marketable securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Stockholders’ equity: Equity, Attributable to Parent [Abstract] Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Contract with customer, liability Deferred revenue, total Contract with Customer, Liability Issuance of common stock upon exercise of stock options (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period At-The-Market At-The-Market [Member] At-The-Market Marketable securities, current Fair Value Debt Securities, Available-for-Sale, Excluding Accrued Interest, Current Document Fiscal Period Focus Document Fiscal Period Focus Schedule of basic and diluted loss per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Accrued expenses and other current liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Antidilutive Securities Antidilutive Securities [Axis] Laboratory equipment Laboratory Equipment [Member] Laboratory equipment. Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss, Current Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Summary of significant accounting policies Significant Accounting Policies [Text Block] Common Stock Common Stock [Member] Foreign Tax Authority Foreign Tax Authority [Member] Level 1 Fair Value, Inputs, Level 1 [Member] City Area Code City Area Code Entity Address, Postal Zip Code Entity Address, Postal Zip Code Product and Service Product and Service [Axis] Loss per share Earnings Per Share [Text Block] Restructuring and related cost, expected number of positions eliminated Restructuring and Related Cost, Expected Number of Positions Eliminated Income Statement Location Income Statement Location [Domain] Summary of property and equipment Property, Plant and Equipment [Table Text Block] Equity Components Equity Components [Axis] Financial Instruments Financial Instruments [Domain] Document Fiscal Year Focus Document Fiscal Year Focus Stock options granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Entity Small Business Entity Small Business Minimum Minimum [Member] Local Phone Number Local Phone Number Denominator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Property and equipment, net Total property and equipment, net Property, Plant and Equipment, Net Research and development milestones Research And Development Milestones [Member] Research and development milestones. Accounts Receivable Receivables, Net, Current Potential research, development and commercial milestone payments Potential Research Development And Commercial Milestone Payments [Member] Potential research, development and commercial milestone payments. Payments for tax withholdings Payments For Tax Withholdings Payments For Tax Withholdings Accrued expenses and other current liabilities: Accrued Liabilities and Other Liabilities [Abstract] Measurement Frequency [Axis] Measurement Frequency [Axis] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Assets Assets [Abstract] Operating lease liability, net of current Operating Lease, Liability, Noncurrent Time-based RSUs Restricted Stock Units (RSUs) [Member] Research extend term Research Extended Term Research extended term. Operating lease liability Increase (Decrease) in Operating Lease Liability Number of performance obligation Number Of Performance Obligation Number of performance obligation. Restated Roche Agreement Restated Roche Agreement [Member] Restated Roche agreement. Depreciation and amortization expense Depreciation Summary of marketable securities Marketable Securities [Table Text Block] Net loss Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest U.S. Treasury securities US Treasury Securities [Member] Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Commitments and contingencies Commitments and Contingencies Disclosure [Text Block] Marketable securities, non-current Fair Value Debt Securities, Available-for-Sale, Excluding Accrued Interest, Noncurrent Income Statement Location Income Statement Location [Axis] Schedule of revenue from collaboration agreements Revenue From Collaboration Agreements Table [Table Text Block] Revenue from collaboration agreements. Collaborative Arrangement and Arrangement Other than Collaborative Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss, Noncurrent Accumulated Deficit Retained Earnings [Member] Interest expense and amortization of long-term debt − related party Interest Expense And Amortization Of Long Term Debt Related Party Interest expense and amortization of long term debt related party. Transaction price allocated to performance obligation Transaction Price Allocated Transaction Price Allocated To Performance Obligation Transaction price allocated to performance obligation. Calico Agreement Calico Agreement [Member] Calico agreement. Payment of long-term debt − related party Repayments of Related Party Debt Schedule of stock-based compensation expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Net (accretion) amortization of (discounts) premiums on marketable securities Accretion (Amortization) of Discounts and Premiums, Investments Total liabilities and stockholders’ equity Liabilities and Equity Upfront payment Upfront Payment Upfront payment. Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax, Noncurrent Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax, Noncurrent Other income (expense), net: Nonoperating Income (Expense) [Abstract] Other assets Other Assets, Noncurrent Research and Development Arrangement, Contract to Perform for Others, Type Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Net loss per share − basic (in dollars per share) Earnings Per Share, Basic Right-of-use asset Operating Lease, Right-of-Use Asset Issuance of common stock under 2020 ESPP Stock Issued During Period, Value, Employee Stock Purchase Plan Accounting Policies [Abstract] Accounting Policies [Abstract] Restructuring and related cost, number of positions eliminated, period percent Restructuring and Related Cost, Number of Positions Eliminated, Period Percent Sale of Stock Sale of Stock [Domain] Restructuring Restructuring Costs 2020 Stock Option and Incentive Plan Two Thousand And Twenty Stock Option And Incentive Plan [Member] 2020 stock option and incentive plan. Share-based compensation, number of common stock issuable per RSU vested (in shares) Share Based Compensation Arrangement By Share Based Payment Award Number Of Common Stock Issuable Per R S U Vested Share-based compensation arrangement by share-based payment award, number of common stock issuable per RSU vested. Payables and Accruals [Abstract] Payables and Accruals [Abstract] Schedule of financial information related to collaboration and license agreements Financial Information Related To Collaboration And License Agreements Table [Table Text Block] Financial information related to the collaboration and license agreements. Product and Service Product and Service [Domain] Schedule of diluted net loss per share attributable to common stockholders Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Option exercise fees Option Exercise Fee Option exercise fee. Entity Address, City or Town Entity Address, City or Town Research and development Research and Development Expense [Member] Cash flows (used in) provided by investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Revenue from Contract with Customer, Product and Service [Extensible Enumeration] Revenue from Contract with Customer, Product and Service [Extensible Enumeration] Total anti-dilutive common stock equivalents (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Award Type Award Type [Axis] Consolidation Consolidation, Policy [Policy Text Block] Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Plan Name Plan Name [Domain] Document Quarterly Report Document Quarterly Report Supplemental disclosures of non-cash investing and financing activities: Noncash Investing and Financing Items [Abstract] Capital expenditures in accounts payable and accrued expenses Capital Expenditures Incurred but Not yet Paid Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Document Transition Report Document Transition Report General and administrative General and Administrative Expense [Member] Property and equipment Property, Plant and Equipment, Gross Calico License Agreement Calico License Agreement [Member] Calico license agreement. Other Adjustments to Additional Paid in Capital, Other Use of estimates Use of Estimates, Policy [Policy Text Block] Proceeds from maturities of marketable securities Proceeds from Sale and Maturity of Marketable Securities Accounts payable Increase (Decrease) in Accounts Payable Common stock, shares authorized Common Stock, Shares Authorized Accrued expenses and other current liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Entity File Number Entity File Number Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Operating lease liability, current Operating Lease, Liability, Current Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Issuances of common stock under 2020 ESPP (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Entity Shell Company Entity Shell Company Annual payments Annual Payments Annual payments. Adjustments to reconcile net loss to cash used in operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Property Plant And Equipment [Line Items] Property, Plant and Equipment [Line Items] Restated Roche Agreement And Biogen License Agreement Restated Roche Agreement And Biogen License Agreement [Member] Restated Roche Agreement And Biogen License Agreement Transaction price from closing of the stock purchase agreement Transaction Price From Closing of the Stock Purchase Agreement Transaction Price From Closing of the Stock Purchase Agreement Research and development services Research And Development Services [Member] Research and development services. Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Cash, cash equivalents and restricted cash at end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Amount eligible to receive Contracts Receivable, Claims and Uncertain Amounts Interest and other income, net Interest and Other Income Price per share (in dollars per share) Sale of Stock, Price Per Share Common stock, shares issued Common Stock, Shares, Issued Research and Development Arrangement, Contract to Perform for Others, Type Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Units vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Deferred revenue, current Contract with Customer, Liability, Current Options to purchase common stock Options To Purchase Common Stock [Member] Options to purchase common stock. Security Exchange Name Security Exchange Name Regulatory milestone achieved Collaborative Arrangement, Regulatory Milestone Achieved Collaborative Arrangement, Regulatory Milestone Achieved Subsequent Event Type Subsequent Event Type [Axis] Total cash equivalents and marketable securities Assets, Fair Value Disclosure Proceeds from exercise of stock options Proceeds from Stock Options Exercised Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Discovery, Regulatory, and Commercial Milestones Discovery, Regulatory, and Commercial Milestones [Member] Discovery, Regulatory, and Commercial Milestones Collaboration and license agreements Collaborative Arrangement Disclosure [Text Block] Stock Options Employee Stock Option [Member] Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Equity Distribution Agreement with Cowen and Company, LLC Equity Distribution Agreement With Cowen And Company L L C [Member] Equity distribution agreement with Cowen and Company, LLC. Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Betta Agreements Betta Agreement [Member] Betta Agreement Expected to be recognized over a weighted average period Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Unaudited interim financial information Unaudited Interim Financial Information Policy [Policy Text Block] Unaudited interim financial information. Other Proceeds from (Payments for) Other Financing Activities Restructuring and related cost, cost incurred to date Restructuring and Related Cost, Cost Incurred to Date Maximum Maximum [Member] Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Number of performance obligations Number of Performance Obligations Number of Performance Obligations Unrecognized compensation costs Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Document Type Document Type Restructuring reserve, current Restructuring Reserve, Current Share price (in dollars per share) Share Price Issuance of common stock upon vesting of restricted stock units, net of shares repurchased for tax withholding (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Entity Registrant Name Entity Registrant Name Accrued expenses and other current liabilities Total accrued expenses and other current liabilities Accrued Liabilities and Other Liabilities Summary of allocation of transaction price Summary Of Allocation Of Total Transaction Price And Unsatisfied Transaction Price Table [Table Text Block] Summary of allocation of total transaction price and unsatisfied transaction price. Antidilutive Securities, Name Antidilutive Securities, Name [Domain] Number of potential research and development targets Number Of Potential Research and Development Targets Number Of Potential Research and Development Targets Number of targets Number Of Targets Number of targets. Stock-based compensation Share-Based Payment Arrangement [Text Block] Biogen Agreement Biogen Agreement [Member] Biogen agreement. Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax, Current Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax, Current Basis of presentation Basis of Accounting, Policy [Policy Text Block] Document Period End Date Document Period End Date Less: accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Schedule of financial assets measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Entity Central Index Key Entity Central Index Key Subsequent event Subsequent Event [Member] Total stock-based compensation expense Share-Based Payment Arrangement, Expense Other Other Liabilities, Current Income tax expense Income tax provision (benefit) Income Tax Expense (Benefit) Income Statement [Abstract] Income Statement [Abstract] Income Tax Authority Income Tax Authority [Domain] Issuance of common stock, net (in shares) Stock Issued During Period, Shares, New Issues Title of 12(b) Security Title of 12(b) Security Fair value measurements Fair Value Disclosures [Text Block] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Share-based payment arrangement, plan modification, incremental cost Share-Based Payment Arrangement, Plan Modification, Incremental Cost Issuance of common stock, net Issuance and sale of common stock Stock Issued During Period, Value, New Issues Equity [Abstract] Equity [Abstract] Debt Securities, Available-for-Sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Issuance of common stock upon vesting of restricted stock units, net of shares repurchased for tax withholding Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Revenue from collaboration agreements Revenue from Contract with Customer, Excluding Assessed Tax Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Amendment Flag Amendment Flag One-time sales-based payments One Time Sales Based Payments [Member] One-time sales-based payments. Money market funds Money Market Funds [Member] Schedule of supplemental financial information related to collaboration and license agreements Supplemental Financial Information Related To Collaboration And License Agreements Table [Table Text Block] Supplemental financial information related to collaboration and license agreements. Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Entity Tax Identification Number Entity Tax Identification Number Cash and cash equivalents Cash and cash equivalents at end of the period Cash and Cash Equivalents, at Carrying Value Number of shares retained to cover statutory minimum withholding taxes (in shares) Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Potential proceeds from collaboration Collaborative Arrangement, Potential Proceeds From Collaboration Collaborative Arrangement, Potential Proceeds From Collaboration Cash paid for interest − related party Interest Paid, Excluding Capitalized Interest, Operating Activities Purchases of marketable securities Payments to Acquire Marketable Securities Statistical Measurement Statistical Measurement [Axis] Financial Instrument Financial Instrument [Axis] Marketable securities: Marketable Securities [Abstract] Entity Interactive Data Current Entity Interactive Data Current Roche Agreement Roche Agreement [Member] Roche agreement. Schedule Of Available For Sale Securities [Table] Debt Securities, Available-for-Sale [Table] Numerator: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Reconciliation of cash, cash equivalents and restricted cash: Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract] Payments for repurchase of common stock for tax withholding Payments for Repurchase of Common Stock Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Weighted-average number of shares used in computed net loss per share − diluted Weighted Average Number of Shares Outstanding, Diluted Accrued research and development Accrued Research And Development Current Accrued research and development, current. Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Accumulated deficit Accumulated deficit Retained Earnings (Accumulated Deficit) Research term Research Term Research term. Commitments and Contingencies Disclosure [Abstract] Operating expenses: Operating Expenses [Abstract] Purchases of property and equipment, net Payments to Acquire Property, Plant, and Equipment Annual research plan payments receivables Annual Research Plan Payments Receivables Annual research plan payments receivables. Additional paid-in capital Additional Paid in Capital, Common Stock Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Additional Paid-In Capital Additional Paid-in Capital [Member] Current assets: Assets, Current [Abstract] Leases [Abstract] Leases [Abstract] Total assets Assets Entity Address, State or Province Entity Address, State or Province Cover [Abstract] Cover [Abstract] Cash flows used in operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Subsequent events Subsequent Events [Text Block] Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Cash paid for leases Operating Lease, Payments Drug Application Approval Drug Application Approval [Member] Drug Application Approval Recurring Fair Value, Recurring [Member] Common stock, shares outstanding Common Stock, Shares, Outstanding Restructuring and Related Activities [Abstract] Option to include number of additional targets Option To Include Number of Additional Targets Option To Include Number of Additional Targets Option rights Option Rights [Member] Option rights. Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Total operating expenses Operating Expenses Other Other Operating Activities, Cash Flow Statement Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Net change in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash flows provided by (used in) financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Common stock, par value per share (in dollars per share) Common Stock, Par or Stated Value Per Share Sale of Stock Sale of Stock [Axis] Equity Component Equity Component [Domain] Net cash (used in) provided by investing activities Net Cash Provided by (Used in) Investing Activities Upfront fees Upfront Fees Upfront fees. Merck Agreement Merck Agreement [Member] Merck Agreement Weighted-average number of shares used in computed net loss per share − basic Weighted Average Number of Shares Outstanding, Basic Entity Current Reporting Status Entity Current Reporting Status Unrealized (loss) gain on marketable securities Change in unrealized loss, net on marketable securities Marketable Security, Unrealized Gain (Loss) Loss from operations Operating Income (Loss) Total liabilities Liabilities Nature of the business and basis of presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Office equipment Office Equipment [Member] Prepaid expenses and other current and long-term assets Increase (Decrease) in Prepaid Expense and Other Assets Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Research and development targets Research And Development Targets [Member] Research and development targets. Cash, cash equivalents and marketable securities Cash, Cash Equivalents, and Short-Term Investments Measurement Frequency [Domain] Measurement Frequency [Domain] Property and equipment Property, Plant and Equipment Disclosure [Text Block] New exercise price per share, tranche one (in dollars per share) Share-Based Compensation Arrangements By Share-Based Payment Award, New Exercise Price Per Share, Tranche One Share-Based Compensation Arrangements By Share-Based Payment Award, New Exercise Price Per Share, Tranche One Deferred revenue, net of current Contract with Customer, Liability, Noncurrent Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Statement [Line Items] Statement [Line Items] Plan Name Plan Name [Axis] Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax [Abstract] New exercise price per share, tranche two (in dollars per share) Share-Based Compensation Arrangements By Share-Based Payment Award, New Exercise Price Per Share, Tranche Two Share-Based Compensation Arrangements By Share-Based Payment Award, New Exercise Price Per Share, Tranche Two Long-Lived Tangible Asset Long-Lived Tangible Asset [Domain] Lead series identification achievement Lead Series Identification Achievement [Member] Lead series identification achievement. Earnings Per Share [Abstract] Earnings Per Share [Abstract] Common stock, par value of $0.0001 per share; 150,000,000 shares authorized, and 68,778,591 and 60,467,188 shares issued and outstanding as of March 31, 2024 and December 31, 2023, respectively Common Stock, Value, Issued Stock repurchase program, number of shares authorized to be repurchased (in shares) Stock Repurchase Program, Number of Shares Authorized to be Repurchased Biogen Research and License Agreement Biogen Research and License Agreement [Member] Biogen license agreement General and administrative General and Administrative Expense Allowance for credit loss Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Collaborative Arrangement [Member]