Repare Therapeutics (RPTX) 10-K 4 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 01, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	RPTX
Entity Registrant Name	Repare Therapeutics Inc.
Entity Central Index Key	0001808158
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Public Float			$ 703,850,221
Entity Common Stock, Shares Outstanding		36,904,446
Title of 12(b) Security	Common Shares, no par value
Security Exchange Name	NASDAQ
Entity File Number	001-39335
Entity Incorporation, State or Country Code	A8
Entity Tax Identification Number	00-0000000
Entity Address, Address Line One	7210 Frederick-Banting
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	St-Laurent
Entity Address, State or Province	QC
Entity Address, Country	CA
Entity Address, Postal Zip Code	H4S 2A1
City Area Code	857
Local Phone Number	412-7018
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Documents Incorporated by Reference	Portions of the definitive proxy statement for the registrant’s 2021 annual meeting of shareholders, which is to be filed within 120 days after the end of the registrant’s fiscal year ended December 31, 2020, are incorporated by reference into Part III of this Form 10-K, to the extent described in Part III.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 326,184	$ 94,797
Marketable securities	7,526
Research and development tax credits receivable	2,011	1,080
Other receivables	4,153	1,976
Prepaid expenses	6,678	719
Total current assets	346,552	98,572
Property and equipment, net	3,948	2,390
Restricted cash	212	208
Operating lease right-of-use assets	4,674	1,034
Other assets	288	359
Deferred tax assets	1,412	132
TOTAL ASSETS	357,086	102,695
Current liabilities:
Accounts payable	2,251	2,127
Accrued expenses and other current liabilities	5,975	1,276
Operating lease liabilities, current portion	697	625
Deferred revenue, current portion	2,073
Income tax payable	18	218
Total current liabilities	11,014	4,246
Operating lease liabilities, net of current portion	3,308	439
Deferred revenue, net of current portion	55,934	8,142
TOTAL LIABILITIES	70,256	12,827
Commitments and Contingencies (note 16)
TOTAL CONVERTIBLE PREFERRED SHARES		135,997
SHAREHOLDERS’ EQUITY (DEFICIT):
Preferred shares, no par value per share; unlimited shares authorized and 0 shares authorized as December 31, 2020 and 2019, respectively; 0 shares issued and outstanding as of December 31, 2020, and 2019, respectively
Common shares, no par value per share; unlimited shares authorized as of December 31, 2020 and 2019; 36,902,924 and 1,528,374 shares issued and outstanding as of December 31, 2020 and 2019, respectively	384,313	1
Additional paid-in capital	5,875	3,811
Accumulated deficit	(103,358)	(49,941)
TOTAL SHAREHOLDERS’ EQUITY (DEFICIT)	286,830	(46,129)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED SHARES AND SHAREHOLDERS’ EQUITY (DEFICIT)	$ 357,086	102,695
Series A Convertible Preferred Shares
Current liabilities:
TOTAL CONVERTIBLE PREFERRED SHARES		53,749
Series B Convertible Preferred Shares
Current liabilities:
TOTAL CONVERTIBLE PREFERRED SHARES		$ 82,248

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Temporary equity shares issued		21,558,393
Temporary equity shares outstanding		21,558,393
Temporary equity, liquidation and redemption value		$ 135,246
Common stock par value
Common stock shares authorized	Unlimited	Unlimited
Common stock shares issued	36,902,924	1,528,374
Common stock shares outstanding	36,902,924	1,528,374
Preferred stock par value
Preferred stock shares authorized	Unlimited
Preferred stock shares authorized		0
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Series A Convertible Preferred Shares
Temporary equity par value	$ 0	$ 0
Temporary equity shares authorized	0
Temporary equity shares authorized		Unlimited
Temporary equity shares issued	0	11,090,135
Temporary equity shares outstanding	0	11,090,135
Temporary equity, liquidation and redemption value	$ 0	$ 52,750
Series B Convertible Preferred Shares
Temporary equity par value	$ 0	$ 0
Temporary equity shares authorized	0
Temporary equity shares authorized		Unlimited
Temporary equity shares issued	0	10,468,258
Temporary equity shares outstanding	0	10,468,258
Temporary equity, liquidation and redemption value	$ 0	$ 82,496

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue:
Collaboration agreements	$ 135
Operating expenses:
Research and development, net of tax credits	40,091	$ 20,995
General and administrative	14,346	5,382
Total operating expenses	54,437	26,377
Loss from operations	(54,302)	(26,377)
Other (expense) income, net
Realized and unrealized (loss) gain on foreign exchange	(664)	712
Change in fair value of Series A Preferred Share tranche obligation		(1,350)
Interest income	240
Other expense	(16)	(6)
Total other expense, net	(440)	(644)
Loss before income taxes	(54,742)	(27,021)
Income tax benefit (expense)	1,325	(195)
Net loss and comprehensive loss	(53,417)	(27,216)
Net loss attributable to common shareholders—basic and diluted	$ (53,417)	$ (27,216)
Net loss per share attributable to common shareholders—basic and diluted	$ (2.66)	$ (17.81)
Weighted-average common shares outstanding—basic and diluted	20,045,602	1,528,374

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Shares and Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Initial Public Offering	Series A Convertible Preferred Shares	Series B Convertible Preferred Shares	Common Shares	Common SharesInitial Public Offering	Additional Paid-in Capital	Accumulated Deficit
Balance at Dec. 31, 2018	$ (22,384)				$ 1		$ 340	$ (22,725)
Temporary equity balance, Shares at Dec. 31, 2018			6,813,340
Temporary equity balance, Value at Dec. 31, 2018			$ 31,873
Balance, Shares at Dec. 31, 2018					1,528,374
Issuance of convertible preferred shares, net of issuance costs			$ 21,876	$ 82,248
Issuance of convertible preferred shares, net of issuance costs, Shares			4,276,795	10,468,258
Series A Tranche 3 termination	2,960						2,960
Share-based compensation expense	511						511
Net loss and comprehensive loss	(27,216)							(27,216)
Balance at Dec. 31, 2019	$ (46,129)				$ 1		3,811	(49,941)
Temporary equity balance, Shares at Dec. 31, 2019	21,558,393		11,090,135	10,468,258
Temporary equity balance, Value at Dec. 31, 2019	$ 135,997		$ 53,749	$ 82,248
Balance, Shares at Dec. 31, 2019					1,528,374
Exercise of vested stock options	$ 799				$ 1,272		(473)
Exercise of common stock options, Shares	416,157				416,157
Share-based compensation expense	$ 2,537						2,537
Issuance of common shares upon initial public offering, net of issuance costs		$ 232,043				$ 232,043
Issuance of common shares upon initial public offering, net of issuance costs , Shares						12,650,000
Conversion of convertible preferred shares into an equivalent number of common shares, Value	135,997		$ (53,749)	$ (82,248)	$ 135,997
Conversion of convertible preferred shares into an equivalent number of common shares, Shares			(11,090,135)	(10,468,258)	21,558,393
Issuance of warrant and conversion into common shares,Value	15,000				$ 15,000
Issuance of warrant and conversion into common shares, Shares					750,000
Net loss and comprehensive loss	(53,417)							(53,417)
Balance at Dec. 31, 2020	$ 286,830				$ 384,313		$ 5,875	$ (103,358)
Temporary equity balance, Shares at Dec. 31, 2020			0	0
Balance, Shares at Dec. 31, 2020					36,902,924

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Shares and Shareholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Initial Public Offering
Stock issuance costs	$ 20,957
Series A Convertible Preferred Shares
Stock issuance costs		$ 5
Series B Convertible Preferred Shares
Stock issuance costs		$ 248

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities:
Net loss and comprehensive loss for the year	$ (53,417)	$ (27,216)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	2,537	511
Depreciation expense	897	605
Change in fair value of Series A Preferred Shares tranche obligation		1,350
Non-cash lease expense	890	362
Foreign exchange (gain) loss	588	(629)
Deferred tax asset	(1,280)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(6,988)	(466)
Research and development tax credits receivable	(909)	(566)
Other receivables	(2,038)	(1,347)
Other non-current assets	71	(464)
Accounts payable	17	833
Accrued expenses and other current liabilities	4,573	611
Operating lease liabilities, current portion	(225)	21
Income tax payable	(200)	218
Operating lease liabilities, net of current portion	(465)	(394)
Deferred revenue	49,865	8,142
Net cash used in operating activities	(6,084)	(18,429)
Cash Flows From Investing Activities:
Purchase of property and equipment	(2,237)	(1,304)
Purchase of marketable securities	(7,526)
Net cash used in investing activities	(9,763)	(1,304)
Cash Flows From Financing Activities:
Proceeds from exercise of stock options	799
Proceeds from issuance of warrant	15,000
Net proceeds from issuance of common shares in initial public offering	232,043
Net cash provided by financing activities	247,842	103,243
Effect of exchange rate fluctuations on cash held	(604)	566
Net Increase In Cash And Cash Equivalents And Restricted Cash	231,391	84,076
Cash and cash equivalents and restricted cash at beginning of year	95,005	10,929
Cash and cash equivalents and restricted cash at end of year	326,396	95,005
Reconciliation Of Cash And Cash Equivalents And Restricted Cash
Cash and cash equivalents	326,184	94,797
Restricted cash	212	208
Total cash and cash equivalents and restricted cash	326,396	95,005
Supplemental Disclosure Of Cash Flow Information:
Cash interest received	216
Cash taxes paid	156	23
Property and equipment purchases incurred but not yet paid	218	40
Right-of-use assets obtained in exchange for new operating lease liability	4,538	1,074
Conversion of Series A and B Preferred Shares into common shares	135,997
Conversion of warrant into common shares	$ 15,000
Series A Preferred Shares
Cash Flows From Financing Activities:
Proceeds from issuance of preferred shares, net		20,995
Series B Preferred Shares
Cash Flows From Financing Activities:
Proceeds from issuance of preferred shares, net		$ 82,248

Organization and Nature of Busi

Organization and Nature of Business	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Nature of Business	1. Organization and Nature of Business Repare Therapeutics Inc. (“Repare” or the “Company”) is a precision medicine oncology company focused on the development of synthetic lethality-based therapies to patients with cancer. The Company was incorporated under the Canada Business Corporations Act Business Corporations Act (Québec) On June 12, 2020, the Company effected a 1-for-6.062 reverse stock split of the Company’s share capital. Accordingly, all common shares, Series A and B convertible preferred shares, stock options and per share amounts in these consolidated financial statements have been retroactively adjusted to reflect the reverse stock split on a retroactive basis for all periods presented. On June 23, 2020, the Company completed its IPO of 12,650,000 of its common shares, including the exercise in full by the underwriters of their option to purchase up to 1,650,000 additional common shares, for aggregate gross proceeds of $253.0 million. The Company’s shares began trading on the Nasdaq Global Select Market under the ticker symbol “RPTX” on June 19, 2020. The Company received $232.0 million in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Upon closing of the IPO, all outstanding convertible preferred shares converted into 21,558,393 common shares and the outstanding warrant was automatically exercised into 750,000 common shares. Since inception, the Company has incurred operating losses. As at December 31, 2020, the Company had an accumulated deficit of $103.4 million. The Company does not have any products approved for sale and has financed its operations primarily through equity financings and funding from its collaboration agreements. Based on its current operating plan, the Company expects that its existing cash and cash equivalents, restricted cash and marketable securities on hand will be sufficient to fund its operating and capital expenditures through 2022. There can be no assurance that the Company will be able to obtain additional debt or equity financing, or generate product revenue or revenue from collaboration agreements, on a timely basis or at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company’s business, results of operations and financial condition.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). Principles of Consolidation The accompanying consolidated financial statements of the Company include the accounts of the Company and its wholly-owned subsidiary, Repare Therapeutics USA Inc. (“Repare USA”), which was incorporated under the laws of Delaware on June 1, 2017. The financial statements of Repare USA are prepared for the same reporting period as the parent company, using consistent accounting policies. All intra-group transactions, balances, income, and expenses are eliminated in full upon consolidation. Foreign Currencies The functional currency for the Company and Repare USA is the U.S. dollar (“USD”). Accordingly, transactions denominated in currencies other than the functional currency are measured and recorded in the functional currency at the exchange rate in effect on the date of the transactions. At each consolidated balance sheet date, monetary assets and liabilities denominated in currencies other than the functional currency are remeasured using the exchange rate in effect at that date. Non-monetary assets and liabilities and revenue and expense items denominated in foreign currencies are translated into the functional currency using the exchange rate prevailing at the dates of the respective transactions. Any gains or losses arising on remeasurement are included in the consolidated statement of operations. Segment Information The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is the research, development and commercialization of precision oncology drugs targeting specific vulnerabilities of tumors in genetically defined patient populations. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in consolidated financial statements and accompanying notes. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, estimates related to revenue recognition, accrued research and development expenses, share-based compensation, right-of-use assets and lease liabilities and income taxes. The Company bases its estimates on historical experience and other market specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. COVID-19 Pandemic With the global spread of the ongoing COVID-19 pandemic, the Company established a cross-functional task force and has implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on its employees and its business, including its preclinical studies and its ongoing and planned clinical trials. The Company’s operations are considered as an “essential business” and therefore, the Company is continuing to operate during this period. The Company has taken measures to secure its research and development activities, while work in its laboratories and facilities has been re-organized to reduce risk of COVID-19 transmission. While the Company is experiencing limited financial impacts at this time, given the global economic slowdown, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic, the Company’s business, financial condition, and results of operations could be materially adversely affected. The Company continues to closely monitor the COVID-19 pandemic as it evolves its business continuity plans, clinical development plans and response strategy. As of the date of these financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. Actual results could differ from these estimates, and any such differences may be material to the Company’s financial statements. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. Cash and cash equivalents include cash held in banks and amounts held in money market funds. Marketable Securities The Company classifies marketable debt securities with a remaining maturity of greater than three months when purchased as available-for-sale. Marketable debt securities with a remaining maturity date greater than one year are classified as non-current where the Company has the intent and ability to hold these securities for at least the next 12 months. The Company’s marketable securities consist of U.S. treasury bills with original maturities greater than 90 days. All of the Company’s marketable securities have a contractual maturity of one year or less. The Company considers its investment portfolio of U.S. treasury bills to be available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices. Unrealized gains and losses are reported in accumulated other comprehensive items in shareholders’ equity (deficit). Amortization and accretion of premiums and discounts are recorded in interest income (expense). Realized gains or losses on debt securities are included in other income (expense). If any adjustments to fair value reflect a decline in value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s statement of operations and comprehensive income (loss). Restricted Cash As of December 31, 2020 and 2019, restricted cash consisted of $0.2 million and $0.2 million, respectively, used to secure a letter of credit denominated in a foreign currency for the benefit of the landlord in connection with one of the Company’s lease agreements (Note 8). Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in accredited financial institutions which may periodically exceed insured limits. The Company deposits its cash in financial institutions that it believes have high credit quality and has not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company’s exposure to foreign exchange risk is primarily related to fluctuations between the Canadian dollar and the U.S. dollar. There are balances in Canadian dollars which are subject to foreign currency fluctuations relating to the impact of translating to U.S. dollars for financial statement presentation. As of December 31, 2020 and 2019, the Company had no significant off-balance sheet risk, such as foreign exchange contracts, option contracts or other foreign hedging arrangements. Comprehensive Loss Comprehensive loss includes net loss as well as other changes in shareholders’ equity (deficit) that result from transactions and economic events other than those with shareholders. For each of the years ended December 31, 2020 and 2019, comprehensive loss was equal to net loss. Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value under U.S. GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1 – Quoted prices in active markets for identical assets or liabilities. • Level 2 – Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3 – Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. An entity may choose to measure financial instruments and certain other items at fair value at specified election dates. Subsequent unrealized gains and losses on items for which the fair value option has been elected will be reported in earnings. The estimated fair values of the Company’s cash and cash equivalents, restricted cash, other assets, accounts payable and accrued expenses and other current liabilities approximate their carrying values. The Company’s marketable securities are carried at fair value, determined according to Level 1 inputs in the fair value hierarchy described above. The Company’s Series A Preferred Share Tranche Obligation liabilities are carried at fair value, determined according to Level 3 inputs in the fair value hierarchy described above. In January 2019, in connection with the closing of the second tranche of Series A Preferred Shares, the liability related to the Series A second tranche obligation was settled. In September 2019, in connection with the Company’s issuance and sale of Series B Preferred Shares, the liability related to the Series A third tranche obligation was terminated (see Notes 3 and 9). Property and Equipment, Net Property and equipment is stated at historical cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Category Estimated Useful Lives Computer equipment 3 years Office equipment 5 years Laboratory equipment 5 years Leasehold improvements the shorter of the lease term and the useful life When assets are retired or disposed of, the assets and related accumulated depreciation are derecognized from the accounts, and any resulting gain or loss is included in the determination of net loss. Expenditures for maintenance and repairs are recorded to expense as incurred. Impairment of Long-Lived Assets The Company evaluates its finite-lived intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value of assets may not be recoverable. Recoverability of these assets is measured by comparing their carrying value to the future net undiscounted cash flows the assets are expected to generate over their remaining economic life. If such assets are considered impaired, the impairment to be recognized is measured by the amount by which the carrying value of the assets exceeds their fair value. Indefinite-lived intangible assets are tested for impairment annually, or more frequently if indicators of impairment are present. To date, no such impairment losses have been recorded. Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the consolidated balance sheet as a right-of-use asset and current and non-current lease liabilities, as applicable. Operating lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the right-of-use assets for straight-line rent expense or any incentives received and remeasure the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification grants the lessee an additional right of use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right of use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease. In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets and allocate all of the contract consideration to the lease component only. Revenue Recognition The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under ASC 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. The Company enters into collaboration and license agreements, which are within the scope of ASC 606, to discover, develop, manufacture, and commercialize product candidates. The terms of these agreements typically contain multiple promises or obligations, which may include: (i) licenses to compounds directed to specific targets (referred to as “exclusive licenses”) and (ii) research and development activities to be performed on behalf of the collaboration partner related to the licensed targets. Payments to the Company under these agreements may include non-refundable license fees, customer option exercise fees, payments for research activities, reimbursement of certain costs, payments based upon the achievement of certain milestones and royalties on any resulting net product sales. The Company first evaluates license and/or collaboration arrangements to determine whether the arrangement (or part of the arrangement) represents a collaborative arrangement pursuant to ASC 808, Collaborative Arrangements (“ASC 808”), based on the risks and rewards and activities of the parties pursuant to the contractual arrangement. The Company accounts for collaborative arrangements (or elements within the contract that are deemed part of a collaborative arrangement), which represent a collaborative relationship and not a customer relationship, outside the scope of ASC 606. The Company’s collaborations primarily represent revenue arrangements. For the arrangements or arrangement components that are subject to revenue accounting guidance, in determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company applies the five-step model. As part of the accounting for these arrangements, the Company must use significant judgment to determine: a) the number of performance obligations based on the determination under step (ii) above and whether those performance obligations are distinct from other performance obligations in the contract; b) the transaction price under step (iii) above; and c) the stand-alone selling price for each performance obligation identified in the contract for the allocation of transaction price in step (iv) above. The Company uses judgment to determine whether milestones or other variable consideration, except for sales-based royalties, should be included in the transaction price as described further below. The transaction price is allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. In determining the stand-alone selling price of a license to the Company’s proprietary technology or a material right provided by a customer option, the Company considers market conditions as well as entity-specific factors, including those factors contemplated in negotiating the agreements as well as internally developed estimates that include assumptions related to the market opportunity, estimated development costs, probability of success and the time needed to commercialize a product candidate pursuant to the license. In validating its estimated stand-alone selling price, the Company evaluates whether changes in the key assumptions used to determine its estimated stand-alone selling price will have a significant effect on the allocation of arrangement consideration between performance obligations. Amounts received prior to revenue recognition are recorded as deferred revenue. Amounts expected to be recognized as revenue within one year following the balance sheet date are classified as current portion of deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized as revenue within one year following the balance sheet date are classified as deferred revenue, net of current portion. Amounts recognized as revenue, but not yet received or invoiced are generally recognized as contract assets. Exclusive Licenses – If the license to the Company’s intellectual property is determined to be distinct from the other promises or performance obligations identified in the arrangement, which generally include research and development services, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. In assessing whether a license is distinct from the other promises, the Company considers relevant facts and circumstances of each arrangement, including the research and development capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. In addition, the Company considers whether the collaboration partner can benefit from the license for its intended purpose without the receipt of the remaining promises, whether the value of the license is dependent on the unsatisfied promises, whether there are other vendors that could provide the remaining promises and whether it is separately identifiable from the remaining promises. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation and whether the license is the predominant promise within the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. If the license is the predominant promise, and it is determined that the license represents functional intellectual property (“IP”), revenue is recognized at the point in time when control of the license is transferred. If it is determined that the license does not represent functional IP, revenue is recognized over time using an appropriate method of measuring progress. Research and Development Services – The obligations under the Company’s collaboration and license agreements generally include research and development services to be performed by the Company to benefit the collaboration partner. For performance obligations that include research and development services, the Company generally recognizes revenue allocated to such performance obligations based on an appropriate measure of progress. The Company utilizes judgment to determine the appropriate method of measuring progress for purposes of recognizing revenue, which is generally an input measure such as costs incurred. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The measure of progress, and thereby periods of which revenue should be recognized, are subject to estimates by management and may change over the course of the contract. Reimbursements from the partner that are the result of a collaborative relationship with the partner, instead of a customer relationship, such as co-development activities, are recorded as a reduction to research and development expense. Customer Options – The Company’s arrangements may provide a collaborator with the right to acquire additional goods or services in the future. Under these agreements, fees may be due to the Company (i) at the inception of the arrangement as an upfront fee or payment or (ii) upon the exercise of the customer option. If an arrangement is determined to contain customer options that allow the customer to acquire additional goods or services, the goods and services underlying the customer options are not considered to be performance obligations at the outset of the arrangement, as they are contingent upon option exercise. The Company evaluates the customer options for material rights, or options to acquire additional goods or services for free or at a discount. If the customer options are determined to represent a material right, the material right is recognized as a separate performance obligation at the inception of the arrangement. The Company allocates the transaction price to material rights based on the relative stand-alone selling price, which is determined based on the identified discount and the probability that the customer will exercise the option. Amounts allocated to a material right are not recognized as revenue until, at the earliest, the option is exercised or expires. Milestone Payments – At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular milestone in making this assessment. There is considerable judgment involved in determining whether it is probable that a significant revenue reversal would not occur. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. If a milestone or other variable consideration relates specifically to the Company’s efforts to satisfy a single performance obligation or to a specific outcome from satisfying the performance obligation, the Company generally allocates the milestone amount entirely to that performance obligation once it is probable that a significant revenue reversal would not occur. Royalties – For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of its licensing arrangements. For a complete discussion of accounting for collaboration revenues, see Note 12. Research and Development Expenses Research and development costs are expensed as incurred. The Company’s research and development expenses consist primarily of costs incurred in performing research and development activities, including salaries and other compensation, share-based compensation, fees paid to external service providers, laboratory supplies and costs for facilities and equipment, partially offset by fully refundable research and development tax credits. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are expensed as the goods are delivered or the services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. Accrued Research and Development Expenses The Company has entered into various research and development contracts. The payments to these agreements are recorded as research and development expenses as incurred. The Company records accrued liabilities for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgements and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Share-Based compensation The Company accounts for all share-based awards granted to employees and non-employees as share-based compensation expense at fair value. Since the Company’s IPO in June 2020, the fair value of the underlying common shares is based on the trading price of the Company’s common shares. Prior to the Company’s IPO, the Company previously engaged an independent valuation firm to determine the fair value of the underlying common shares. The independent valuation firm used valuation techniques and methods that comply with guidance provided by the American Institute of Certified Public Accountants in its Accounting & Valuation Guide. Each valuation methodology included estimates and assumptions that required the Company’s judgment. These estimates and assumptions included a number of objective and subjective factors in determining the value of the Company’s common shares at each grant date, including: (1) prices paid for the Company’s convertible preferred shares, which the Company has sold to outside investors in arm’s-length transactions, and the rights, preferences and privileges of the Company’s convertible preferred shares and common shares; (2) valuations performed by an independent valuation specialist; (3) the Company’s stage of development; (4) the fact that grants of share-based awards involved illiquid securities in a private company; and (5) the likelihood of achieving a liquidity event for the common shares underlying the share-based awards, such as an initial public offering or sale of the Company, given prevailing market conditions. The measurement date for employee and non-employee awards is the date of grant, and share-based compensation costs are recognized over the employees’ requisite service period, which is the vesting period, on a straight-line basis. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected share price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option and the Company’s expected dividend yield. As there was no public market for its common shares prior to its IPO, the Company determined the volatility for awards granted based on an analysis of reported data for a group of guideline companies that issued options with substantially similar terms. The expected volatility has been determined using a weighted-average of the historical volatility measures of this group of guideline companies. The Company expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded share price. The expected term of the Company’s stock options granted to employees and non-employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. In connection with the adoption of ASU No. 2018-07, Compensation—Stock Compensation (“ASU No. 2018-07”), the Company calculated the expected term of non-employee awards using the midpoint between the vesting date and the contractual term, which is consistent with the method used for employee awards. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common shares; therefore, the expected

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of December 31, 2020: Description December 31, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Observable Inputs (Level 3) (in thousands) Assets Cash equivalents Money market funds $ 2,455 $ 2,455 $ — $ — Marketable securities U.S. Treasury notes 7,526 7,526 — — Total financial assets $ 9,981 $ 9,981 $ — $ — When developing fair value estimates, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. When available, the Company uses quoted market prices to measure the fair value. The valuation technique used to measure fair value for the Company’s Level 1 assets is a market approach, using prices and other relevant information generated by market transactions involving identical or comparable assets. If market prices are not available, the fair value measurement is based on models that use primarily market-based parameters including yield curves, volatilities, credit ratings and currency rates. In certain cases where market rate assumptions are not available, the Company is required to make judgements about assumptions market participants would use to estimate the fair value of a financial instrument. During the year ended December 31, 2020, there were no transfers between fair value measure levels. The Company had no financial assets and liabilities measured at fair value as of December 31, 2019. Series A Preferred Share Tranche Obligation The Company determined that its obligation to issue, and the Company’s investors’ obligation to purchase, additional Series A Preferred Shares at a fixed price (i.e., the issuance price) in subsequent tranches following the initial closing of the Series A Preferred Share financing represented a freestanding financial instrument, the Series A Preferred Share Tranche Obligation. The freestanding financial instrument was classified as an asset or liability on the Company’s consolidated balance sheets and initially recorded at fair value, with changes in fair value for each reporting period recognized in other income (expense), net in the consolidated statements of operations and comprehensive loss (Note 9). In connection with the Company’s issuance of the Series A Preferred Shares in June 2017 (Note 9), the Company recognized the Series A Preferred Share Tranche Obligation at the initial fair value which was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The fair value of the obligation was estimated based on results of a third-party valuation. This obligation is remeasured prior to the issuance of subsequent tranches and at each subsequent reporting period. As such, the proceeds from the Series A Preferred Share financing were allocated between the Series A Preferred Share Tranche Obligation and Series A Preferred Shares using the residual method, with the Series A Preferred Share Tranche Obligation being recorded at its fair value and the Series A Preferred Shares at the residual value. Each tranche obligation is valued as a forward contract. The values were determined using a probability-weighted present value calculation. In determining the fair values of the tranche obligations, estimates and assumptions impacting fair value included the estimated future values of the Company’s Series A Preferred Shares, discount rates, estimated time to liquidity and probability of each tranche closing. The Company determined the per share future value of the Series A Preferred Shares by back-solving to the initial proceeds of the Series A Preferred Share financing. The Company remeasured each tranche obligation at each reporting period and prior to settlement. A change in the assumptions related to the valuation of the Series A Preferred Share Tranche Obligation could have a significant impact on the value of the obligation. The Company recorded other expense of $1.35 million The following table provides a roll forward of the aggregate fair value of the Company’s Series A Preferred Share Tranche Obligation for which fair value was determined using Level 3 inputs: Series A Preferred Share Tranche Obligation (in thousands) Balance as of December 31, 2018 $ 2,490 Change in fair value 1,350 Tranche 2 settlement of obligation (880 ) Tranche 3 termination (2,960 ) Balance as of December 31, 2019 $ —

Cash and Cash Equivalents and M

Cash and Cash Equivalents and Marketable Securities	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Cash and Cash Equivalents and Marketable Securities	4. Cash and Cash Equivalents and Marketable Securities As of December 31, 2020, cash and cash equivalents and marketable securities were comprised of the following: Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) As at December 31, 2020 Money market funds included in cash and cash equivalents $ 2,455 $ — $ — $ 2,455 Marketable securities: U.S. Treasury notes 7,526 — — 7,526 Total $ 9,981 $ — $ — $ 9,981 The amortized cost of marketable securities at December 31, 2020 is equal to their fair value due to the Company investing in marketable securities at the end of year. Accordingly, no unrealized gains or losses were recognized in the year ended December 31, 2020. As of December 31, 2019, the Company did not hold any money market funds or marketable securities.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property and Equipment, Net	5. Property and Equipment, Net Property and equipment, net as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 (in thousands) Computer equipment $ 301 $ 256 Office equipment 216 177 Laboratory equipment 4,718 2,565 Leasehold improvements 706 488 Total 5,941 3,486 Less: Accumulated depreciation (1,993 ) (1,096 ) Property and equipment, net $ 3,948 $ 2,390 In the year ended December 31, 2020, the Company recognized depreciation expense of $0.9 million, of which $0.8 million was included in research and development expense and $0.1 million was included in general and administrative expense. In the year ended December 31, 2019, the Company recognized depreciation expense of $0.6 million, of which $0.5 million was included in research and development expense and $0.1 million was included in general and administrative expense.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	6. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 (in thousands) Accrued compensation and benefits $ 2,771 $ 1,043 Accrued research and development expense 2,584 208 Accrued professional services 436 21 Other 184 4 Total accrued expenses and other current liabilities $ 5,975 $ 1,276

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2020
License Agreements [Abstract]
License Agreements	7. License Agreements In December 2016, as further amended in February 2017 and amended and restated in July 2018, the Company entered into a license agreement (the “NYU Agreement”) with New York University, pursuant to which the Company obtained a worldwide, royalty-bearing, exclusive license under certain patents and know-how of New York University to research, develop and commercialize products covered by such licensed patents. The Company is required to pay New York University an annual non-refundable license fee, which is creditable against future milestone and royalty payments. The Company is required to pay amounts up to approximately $6.7 million in the aggregate upon achievement of certain clinical and commercial milestones and pay a low single digit royalty on future net sales of any product covered by a licensed product and a lower-single digit royalty on future net sales of any product not covered by a licensed product. The NYU Agreement expires on the date of expiration of all royalty obligations. Any potential future milestone or royalty payment amounts have not been accrued at December 31, 2020 and 2019 due to the uncertainty related to the successful achievement of these milestones.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	8. Leases The Company has historically entered into lease arrangements for its facilities and certain equipment. As of December 31, 2020, the Company had four operating leases with required future minimum payments. The Company’s leases generally do not include termination or purchase options. Operating Leases In June 2017, the Company entered into a lease agreement for office and laboratory space in Montreal, Quebec, for a four-year term, ending in July 2021. As required under the terms of the lease agreement, the lease requires a standby letter of credit in the amount of $212, which remains unused as of December 31, 2020. In November 2017, and as further amended throughout 2018, 2019 and 2020, the Company entered into a lease agreement for office and laboratory space located in Montreal, Quebec, for a three-year term ending in October 2020 which was extended through October 2022. In June 2019, and further amended in August 2019, the Company entered into a lease agreement for office space in Cambridge, Massachusetts, for a two-year term, ending in May 2021. In November 2019, the Company entered into a lease agreement for office and laboratory space for a 5 year term located in Montreal, Quebec which commenced in September 2020. The Company has an option for a 5 year renewal, which has not been recognized in the Company’s right-of-use asset or lease liability. As required under the terms of the lease agreement, the Company incurred prepaid rent of $1.0 million prior to commencement of the lease term, with the current portion previously accounted for within prepaid expenses and other current assets and the long-term portion accounted for within other assets. As of the commencement of the lease term, this prepaid rent has been reclassified to the right-of-use asset. The following tables contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the years ended December 31, 2020 and 2019: December 31, 2020 December 31, 2019 (in thousands) Operating Leases Lease Cost Operating lease cost $ 999 $ 411 Short-term lease cost 51 12 Variable lease cost 161 248 Total lease cost $ 1,211 $ 671 December 31, 2020 December 31, 2019 Other Operating Lease Information (in thousands, except as specified otherwise) Operating cash flows for operating leases $ 802 $ 426 Right-of-use assets obtained in exchange for new operating lease liability $ 4,538 $ 1,074 Weighted-average remaining lease term 4.5 years 1.79 years Weighted-average discount rate 5.1 % 7.6 % Variable lease costs for the years ended December 31, 2020 and 2019 include contingent rental usage, common area maintenance and other operating charges. As the Company’s leases do not provide an implicit rate, the Company utilized its incremental borrowing rate to discount lease payments, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Future minimum lease payments under the Company’s operating leases as of December 31, 2020 were as follows: December 31, 2020 (in thousands) Maturity of Lease Liabilities 2021 $ 871 2022 780 2023 1,053 2024 1,069 2025 720 Total lease payments $ 4,493 Less: interest (488 ) Total lease liabilities $ 4,005

Convertible Preferred Shares

Convertible Preferred Shares	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Convertible Preferred Shares	9. Convertible Preferred Shares In June 2017, the Company authorized the issuance of an unlimited number of Series A Preferred Shares with no par value in connection with the sale and issuance of up to 13,237,696 Series A Preferred Shares. The Series A Preferred Share financing was structured to close in three tranches, each contingent upon the achievement of certain specified milestones. In June 2017, in connection with the closing of the first tranche of Series A Preferred Shares, the Company issued 5,906,049 Series A Preferred Shares at $4.91 per share for total proceeds of $29.0 million, net of issuance costs of $0.04 million and converted previously issued and outstanding Convertible Notes amounting to $4.5 million issued in October 2016 and April 2017 into 907,291 Series A Preferred Shares. The terms included the obligation of the investors to purchase, and the Company to sell, up to 7,331,647 additional Series A Preferred Shares contingent upon the achievement of certain specified milestones. The Company concluded that the obligation and right to make future issuances of Series A Preferred Shares met the definition of a freestanding financial instrument, as the rights were legally detachable from the Series A Preferred Shares (Note 3). In January 2019, in connection with the closing of the second tranche of Series A Preferred Shares, the Company issued 4,276,795 Series A Preferred Shares at $4.91 per share for total gross proceeds of $21.0 million, and the liability related to the Series A second tranche obligation was settled and recognized at fair value as Series A Preferred Shares. In August 2019, the Company authorized the issuance of an unlimited number of Series B Preferred Shares with no par value. In September 2019, the Company issued 10,468,258 Series B Preferred Shares to existing and new investors at $7.88 per share for total proceeds of $82.5 million. In connection with the issuance and sale of Series B Preferred Shares, the Series A third tranche obligation liability was terminated and recognized as additional paid-in-capital. The carrying value of the Series A Preferred Shares was based on the net proceeds received at initial issuance net of the fair value of the Series A Preferred Share Tranche Obligation. At issuance of the first and second tranches, no beneficial conversion features were present. The carrying value of the Series B Preferred Shares was based on the net proceeds received. At initial issuance, no beneficial conversion features were present. Upon completion of the IPO in June 2020, all issued and outstanding Series A and Series B convertible preferred shares were converted into 21,558,393 common shares and the existing classes of Series A and Series B convertible preferred shares were removed. As of December 31, 2019, preferred shares consisted of the following in the table below: December 31, 2019 Preferred Shares Issued and Outstanding Carrying Value Liquidation Value Common Shares Issuable Upon Conversion (in thousands, except share amounts) Series A Preferred Shares 11,090,135 $ 53,749 $ 52,750 11,090,135 Series B Preferred Shares 10,468,258 82,248 82,496 10,468,258 21,558,393 $ 135,997 $ 135,246 21,558,393 The following is a summary of the rights and privileges of the holders of the preferred shares. Voting Rights The holders of preferred shares were entitled to vote, together with the holders of common shares, on all matters submitted to the shareholders for a vote and were entitled to the number of votes equal to the number of whole common shares into which the preferred shares held by such holders could convert on the record date for determination of shareholders entitled to vote. Except for meetings at which only holders of another specified class are entitled to vote, the holders of preferred shares would vote together with the holders of common shares and vote as a single class. Dividends The holders of the preferred shares were entitled to receive, prior and in preference to any dividends on any other common shares of the Company, noncumulative dividends of 8% per annum of the sum of the preferred shares issuance price and all declared but unpaid dividends accrued thereon only when and if declared by the board of directors. Conversion The preferred shares were convertible into common shares on a one-to-one basis. Each preferred share was convertible into common shares, at any time, at the option of the holder, and without the payment of additional consideration, at the applicable conversion ratio in effect for preferred shares, which was initially one-to-one and subject to adjustment for certain anti-dilutive events. In addition, each preferred share was automatically converted into common shares at the applicable conversion ratio in effect for preferred shares upon either (i) the closing of a qualified initial public offering of its common shares at a price per share of at least $15.76 per share (subject to adjustment for any share split, combination or dividend or distribution payable) resulting in $50,000 or more in gross proceeds to the Company, or (ii) the election to convert the preferred shares by at least 70% of the holders of preferred shares. Liquidation Rights In the event of any liquidation, dissolution or winding-up of the affairs of the Company, or unless waived by 70% of the holders of preferred shares, a sale of the Company that resulted in a change of control or a sale of substantially all of the Company’s assets or intellectual property, the holders of preferred shares were entitled to be paid, in priority to the holders of any other class of shares, a liquidation preference equal to the aggregate of all accrued but unpaid dividends on the preferred shares. After satisfying the liquidation preference, the holders of record of preferred shares would have been entitled to receive ratably with the holders of common shares the residual assets of the Company on an as-converted basis.

Shareholders_ Equity (Deficit)

Shareholders’ Equity (Deficit)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Shareholders’ Equity (Deficit)	10. Shareholders’ Equity (Deficit) Convertible Preferred Shares The Company’s Series A and Series B convertible preferred shares were convertible on a one-to-one basis into common shares. Upon completion of the IPO, all issued and outstanding Series A and Series B convertible preferred shares were converted into 21,558,393 common shares and the existing class of Series A and Series B convertible preferred shares were removed. Preferred Shares Effective upon the closing of the IPO, the Company authorized for issue an unlimited number of preferred shares, issuable in series, having such designations, rights, privileges, restrictions and conditions, including dividend and voting rights as the board of directors of the Company may determine, and such rights and privileges, including dividend and voting rights, may be superior to those of the common shares. No preferred shares were issued and outstanding as of December 31, 2020. Warrant In conjunction with the collaboration and license agreement with Bristol Myers Squibb, the Company entered into a warrant agreement with an affiliate of Bristol Myers Squibb pursuant to which the Company issued a warrant for total proceeds of $15,000 on May 26, 2020. Upon closing of the IPO, the warrant was automatically exercised at the public offering price of $20.00 per share into 750,000 common shares of the Company. Common Shares The articles of continuance of the Company authorize an unlimited number of common shares, voting and participating, without par value. Each common share entitles the holder to one vote on all matters submitted to the shareholders for a vote. The holders of common shares are entitled to receive dividends, as may be declared by the board of directors, if any. Through December 31, 2020, no cash dividends have been declared or paid. On June 23, 2020, the Company completed its IPO of 12,650,000 of its common shares, including the exercise in full by the underwriters of their option to purchase up to 1,650,000 additional common shares, at the public offering price of $20.00 per share, for aggregate gross proceeds of $253,000. The Company received $232,043 in net proceeds after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Upon closing of the IPO, all outstanding convertible preferred shares converted into 21,558,393 common shares and the outstanding warrant automatically converted into 750,000 common shares. 2020 Employee Share Purchase Plan In June 2020, the Company’s board of directors adopted, and the Company’s shareholders approved the 2020 Employee Share Purchase Plan (“ESPP”). The maximum number of common shares that may be issued under the ESPP was initially 327,000. Additionally, the number of shares reserved and available for issuance under the ESPP will automatically increase each January 1, beginning on January 1, 2021 and each January 1 thereafter through January 31, 2030, by the lesser of (1) 1.0% of the total number of common shares outstanding on December 31 of the preceding calendar year, (2) 3,300,000 common shares, or (3) such smaller number of common shares as the Company’s board of directors may designate. As of January 1, 2021, the number of common shares that may be issued under the ESPP is 696,029. The ESPP enables eligible employees to purchase common shares of the Company at the end of each offering period at a price equal to 85% of the fair market value of the shares on the first business day or the last business day of the offering period, whichever is lower. Participation in the ESPP is voluntary. Eligible employees become participants in the ESPP by enrolling in the plan and authorizing payroll deductions. Payroll deductions that have accumulated during a particular offering are used to purchase shares of the Company’s shares at the discounted price. The Company makes no contributions to the ESPP. A participant may withdraw from the ESPP or suspend contributions to the ESPP. If the participant elects to withdraw during an offering, all contributions are refunded as soon as administratively practicable. If a participant elects to withdraw or suspend contributions, they will not be able to re-enroll in the current offering but may elect to participate in future offerings. The ESPP purchases only whole shares of the Company’s shares. The Company’s first ESPP offering period began February 16, 2021 and will end on August 13, 2021. Subsequent offering periods will be on a rolling six-month basis. As of December 31, 2020, no common shares have been issued under the ESPP.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11. Share-Based Compensation Option Plan and 2020 Plan In December 2016, as further amended in December 2017 and September 2019, the Company adopted the Repare Therapeutics Inc. Option Plan (the “Option Plan”) for the issuance of stock options and other share-based awards to directors, officers, employees or consultants. The Option Plan authorized up to 4,074,135 shares of the Company’s common shares to be issued. In June 2020, the Company’s board of directors adopted, and the Company’s shareholders approved the 2020 Equity Incentive Plan (the “2020 Plan”). The 2020 Plan became effective on the effective date of the IPO, at which time the Company ceased making awards under the Option Plan. The 2020 Plan allows the Company’s compensation committee to make equity-based and cash-based incentive awards to the Company’s officers, employees, directors and consultants. A total of 3,600,000 common shares were initially reserved for issuance under the 2020 Plan, plus the number of shares (not to exceed 3,807,448 shares) consisting of (i) 298,605 common shares that were available for issuance of awards under the Option Plan at the time the 2020 Plan became effective, which ceased to be available for future issuance under the Option Plan at such time and (ii) any shares subject to outstanding options or other share awards that were granted under the Option Plan that terminate or expire prior to exercise or settlement; are forfeited because of the failure to vest; or are reacquired or withheld (or not issued) to satisfy a tax withholding obligation or the purchase or exercise price. In addition, the number of shares reserved and available for issuance under the 2020 Plan will automatically increase each January 1, beginning on January 1, 2021 and each January 1 thereafter through January 1, 2030, by 5% of the outstanding number of common shares on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s board of directors. As of January 1, 2021, the number of common shares reserved for issuance under the 2020 Plan is 5,780,864. The 2020 Plan is administered by the board of directors. The exercise prices, vesting and other restrictions are determined by the board of directors, except that the exercise price per share of stock option may not be less than 100% of the fair value of the common share on the date of grant, determined based on the average of the daily volume-weighted average trading price of shares on each of the five trading days immediately preceding the date of grant. Stock options awarded under the 2020 Plan expire 10 years after the grant and generally have vesting conditions of 25% on the first anniversary of the date of grant and 75% on a monthly basis at a rate of 1/36 th Option Activity The assumptions that the Company used in the Black Scholes option-pricing model to determine the grant date fair value of stock options granted to employees and non-employees were as follows, presented on a weighted-average basis: Year Ended December 31, 2020 2019 Risk-free interest rate 0.45 % 1.94 % Expected term (in years) 6.07 6.10 Expected volatility 72.26 % 71.41 % Expected dividend yield 0.00 % 0.00 % The grant date fair value of stock options granted was $11.73 per option in 2020 and $1.27 per option in 2019. The following table summarizes the Company’s stock option activity: 2020 2019 Number of shares Weighted average exercise price Weighted average remaining contractual term (in years) Intrinsic value (in thousands) Number of shares Weighted average exercise price Weighted average remaining contractual term (in years) Outstanding, January 1 3,505,119 $ 2.07 8.98 907,315 $ 1.66 8.55 Granted 1,083,274 $ 18.57 2,761,034 $ 2.21 Exercised (416,157 ) $ 1.92 - $ - Forfeited (40,113 ) $ 3.91 (163,230 ) $ 2.06 Outstanding, December 31 4,132,123 $ 6.39 8.64 $ 115,328 3,505,119 $ 2.07 8.98 Options exercisable, December 31 1,217,497 $ 1.96 7.87 $ 39,374 611,927 $ 1.69 6.75 Options unvested, December 31 2,914,626 $ 8.25 8.96 $ 75,926 2,893,192 $ 2.15 9.45 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common shares for those stock options that had an exercise price lower than the fair value of the Company’s common shares. The aggregate intrinsic value of options exercised during the year ended December 31, 2020 was $5.7 million. The total fair value of options vested during the years ended December 31, 2020 and 2019 was $1.3 million and $0.3 million, respectively. During the year ended December 31, 2020, an aggregate of 416,157 options were exercised at a weighted-average exercise price of $1.92 per share, for aggregate proceeds of $0.8 million. As a result, an amount of $0.5 million previously included in additional paid-in-capital related to the exercised options has been credited to common shares and deducted from additional paid-in-capital. Share-Based Compensation Share-based compensation expense was allocated as follows: Year Ended December 31, 2020 2019 (in thousands) Research and development $ 890 $ 250 General and administrative 1,647 261 Total share-based compensation expense $ 2,537 $ 511 As of December 31, 2020 and 2019, there was $13.6 million and $3.6 million of unrecognized share-based compensation expense related to unvested stock options, respectively. The unrecognized share-based compensation expense is expected to be recognized over a weighted-average remaining vesting period of 2.6 and 3.2 years at December 31, 2020 and 2019, respectively.

Collaborations

Collaborations	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaboration	12. Collaborations Ono In January 2019, the Company entered into a research services, license and collaboration agreement (the “Ono Agreement”) with Ono Pharmaceutical Co., Ltd. (“Ono”), a Japanese pharmaceutical company, pursuant to which the Company and Ono have agreed to collaborate in the research of potential product candidates targeting Polθ and the development of the Company’s small molecule Polθ inhibitor program. The Company is primarily responsible for carrying out research activities to identify a product candidate, to be licensed to Ono, in accordance with a mutually agreed upon research plan during a research term that will end upon the earlier of the date of the first submission of an Investigational New Drug application (“IND”) in the United States or Japan, or the end of the research term. In the event that Ono elects to collaborate on the subsequent development and commercialization of the proposed product candidate, Ono will be then responsible for such activities in Japan, South Korea, Taiwan, Hong-Kong, Macau and the Association of Southeast Asian Nations (collectively, the “Ono territory”), and the Company will be responsible for all such activities in the rest of the world outside the Ono territory, including the United States, Canada and European Union. Under the terms of the Ono Agreement, the Company received non-refundable upfront payments of ¥900 million ($8.1 million), consisting of an initial upfront fee payment of ¥110 million ($1.0 million) and an initial upfront research service payment of ¥790 million ($7.1 million). Additionally, in connection with the research activities to be conducted pursuant to the Ono Agreement, the Company is eligible to receive additional research service payments of up to an aggregate of ¥750 million ($7.3 million) upon the occurrence of certain specified research triggers. The Company is also entitled to receive clinical, regulatory and commercial milestone payments of up to ¥17.21 billion ($166.7 million) in the aggregate, plus a tiered percentage royalty on annual net sales in Ono’s Territory ranging from high-single digits to low teens, subject to certain specified reductions. All future milestone payments and royalties are payable in USD. Additionally, upon election by Ono to collaborate on the proposed product candidate, Ono shall be responsible for a specified percentage of research and development costs for the IND-enabling studies of the selected product candidate. The Company assessed the arrangement in accordance with ASC 606 and concluded that Ono is a customer based on the arrangement structure. The Company identified a single performance obligation under the arrangement consisting of the combination of the license to develop and commercialize a selected product candidate targeting Polθ and associated research services. The Company determined that the license and research services are not distinct within the context of the contract, and the license is the predominant good or service. Accordingly, revenue is recognized in accordance with guidance for licenses, and because the license represents functional IP, it is recognized at the point in time control of the license is transferred. The Company determined that the transaction price at the onset of the arrangement is the total upfront payments received in the aggregate amount of $8.1 million which is recorded as deferred revenue as of December 31, 2020 and 2019. The future milestone payments represent variable consideration that is fully constrained at inception of the arrangement as the achievement of the milestone events are highly uncertain. The Company will reevaluate the likelihood of achievement of the milestones at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, and, if necessary, adjust its estimate of the transaction price. Bristol Myers Squibb In May 2020, the Company entered into a collaboration and license agreement with Bristol-Myers Squibb Company (“Bristol-Myers Squibb”), pursuant to which the Company and Bristol Myers Squibb have agreed to collaborate in the research and development of potential new product candidates for the treatment of cancer. The Company is providing Bristol Myers Squibb access to a selected number of its existing screening campaigns and novel campaigns. The Company is responsible for carrying out early-stage research activities directed to identifying potential targets for potential licensing by Bristol Myers Squibb, in accordance with a mutually agreed upon research plan and will be solely responsible for such costs. The collaboration consists of programs directed to both druggable targets and to targets commonly considered undruggable to traditional small molecule approaches. Upon Bristol Myers Squibb’s election to exercise its option to obtain exclusive worldwide licenses for the subsequent development, manufacturing and commercialization of a program, Bristol Myers Squibb will then be solely responsible for all such worldwide activities and costs. The collaboration and license agreement was subsequently amended in July, September and November 2020 to include additional campaigns to the list of existing campaigns from which Bristol Myers Squibb may select campaigns under the agreement and to enable unblinding of a Bristol Myers Squibb alliance manager in order to streamline the collaboration process. Under the terms of the agreement, Bristol Myers Squibb paid the Company an initial nonrefundable upfront fee payment of $50.0 million in June 2020. The Company is entitled to receive, on a program-by-program basis, option exercise fees ranging in the low six figures depending on the nature of the applicable program. Bristol Myers Squibb also has the right to retain rights to certain back-up programs in exchange for a one-time payment in the low eight figures per program. The Company is also entitled to receive up to $301.0 million in total milestones on a program-by-program basis, consisting of $176.0 million in the aggregate for certain specified research, development and regulatory milestones and $125.0 million in the aggregate for certain specified commercial milestones. The Company is further entitled to a tiered percentage royalty on annual net sales ranging from high-single digits to low-double digits, subject to certain specified reductions. Royalties are payable by Bristol Myers Squibb on a licensed product-by-licensed product and country-by-country basis until the later of the expiration of the last valid claim covering the licensed product in such country, expiration of all applicable regulatory exclusivities in such country for such licensed product and the tenth anniversary of the first commercial sale of such licensed product in such country. On a program-by-program basis, prior to the earlier of such program ceasing to be included under the agreement and expiration of the last to expire royalty term for such program, the Company, alone and with third parties, is prohibited from researching, developing, manufacturing and commercializing products that are directed to the applicable target for such program. The Company has provided Bristol Myers Squibb with certain, limited rights to first negotiation if the Company determines to divest, license or collaborate with others regarding certain existing programs, including in the event that the Company receives an unsolicited offer to do so. The right of first negotiation expressly excludes any potential change of control transaction, as defined in the agreement. The collaboration term will expire 42 months after the effective date of the agreement. The agreement will expire, assuming that Bristol Myers Squibb has exercised at least one option for a program, on a licensed product-by-licensed product and country-by-country basis on expiration of the applicable royalty term and in its entirety upon expiration of the last royalty term. Either party may terminate earlier upon an uncured material breach of the agreement by the other party, or the insolvency of the other party. Additionally, Bristol Myers Squibb may terminate the agreement for any or no reason on a program-by-program basis upon specified written notice. The Company assessed the collaboration and license agreement in accordance with ASC 606, Revenue from Contracts with Customers The Company determined that the transaction price at the onset of the agreement is the total non-refundable upfront payment received of $50.0 million. Additional consideration is to be paid to the Company upon the exercise of options to license targets and future milestone payments. The Company utilized the most likely method approach and concluded that these amounts were constrained as they represent option fees and milestone payments that can only be achieved subsequent to option exercises. As such, the Company excluded this additional consideration from the transaction price. The Company has allocated the transaction price of $50.0 million to each performance obligation based on the relative stand-alone selling price of each performance obligation at inception, which was determined based on each performance obligation’s estimated stand-alone selling price. The Company has determined the estimated stand-alone selling price at contract inception of the research activities based on internal estimates of the costs to perform the services, inclusive of a reasonable profit margin. Significant inputs used to determine the total costs to perform the research activities included the length of time required, the internal hours expected to be incurred on the services and the number and costs of various studies that will be performed to complete the research plan. The Company determined the estimated stand-alone selling price at contract inception of the material rights associated with options to obtain exclusive licenses to druggable targets and undruggable targets based on the fees Bristol Myers Squibb would pay to exercise these options, the probability-weighted value of expected future cash flows associated with each license related to each target and the probability that these options would be exercised by Bristol Myers Squibb. In developing such estimates, the Company also considered applicable market conditions and relevant entity-specific factors, including those factors contemplated in negotiating the agreement, probability of success and the time needed to commercialize a product candidate pursuant to the associated license. Based on the relative stand-alone selling price, the allocation of the transaction price to the separate performance obligations was as follows: Performance obligation Transaction price (in thousands) Research activities 6,405 Options to license druggable targets 31,148 Options to license undruggable targets 12,447 Total transaction price 50,000 Revenue associated with the options has been deferred and will be recognized at the point in time when options to license are exercised by Bristol Myers Squibb or upon expiry of such options. Revenue associated with the research activities has been deferred and will be recognized on a proportional performance basis over the period of service for research activities, being the collaboration term, using input-based measurements of total costs of research incurred to estimated proportion performed. Progress towards completion is remeasured at the end of each reporting period. During the year ended December 31, 2020, the Company recognized $0.1 million as revenue associated with the Bristol Myers Squibb collaboration in relation to research activities performed to date. As at December 31, 2020, no options have been exercised by Bristol Myers Squibb. As of December 31, 2020, there was $49.9 million of deferred revenue related to the Bristol Myers Squibb collaboration and license agreement, of which $2.1 million was classified as current and $47.8 million as non-current in the consolidated balance sheet based on the period the services are expected to be performed. In conjunction with entry into the collaboration and license agreement, the Company entered into a warrant agreement with an affiliate of Bristol Myers Squibb pursuant to which the Company issued a warrant for total proceeds of $15.0 million. Upon closing of the IPO, this warrant was automatically exercised into 750,000 common shares of the Company. The Company evaluated whether the warrant should be treated as a separate agreement or a single arrangement with the collaboration and license agreement. Although the warrant agreement was negotiated concurrently with the collaboration and license agreement, the warrant was issued at fair value. Accordingly, the Company accounted for the warrant agreement separately from the collaboration and license agreement.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes Loss before the provision for income taxes for the years ended December 31, 2020 and 2019 consisted of the following: Year Ended December 31, 2020 2019 (in thousands) Canada $ (55,446 ) $ (27,355 ) Foreign $ 704 $ 334 $ (54,742 ) $ (27,021 ) A reconciliation between tax expense and the product of accounting income multiplied by the statutory income tax rate for years ended December 31, 2020 and 2019 is as follows: Year Ended December 31, 2020 2019 (in thousands) Loss before income taxes $ (54,742 ) $ (27,021 ) Income tax at statutory rate 26.5 % 26.5 % Computed income tax recovery (14,507 ) (7,160 ) Effect on income tax resulting from: Federal investment tax credit (2,347 ) (985 ) Accounting charges not deductible for tax purposes 346 277 Other (306) (16 ) Change in valuation allowance 15,489 8,079 Tax (benefit) expense $ (1,325 ) $ 195 During the year ended December 31, 2020, the Company applied operating loss carryforwards to offset taxable income in Canada, arising primarily from the upfront payment received from the collaboration agreement with Bristol Myers Squibb. As of December 31, 2020, the Company had tax losses of approximately $19.2 million, which are available to offset future taxable income in Canada. The Company has not recognized the tax benefit of these losses. These losses expire as follows: (in thousands) 2040 $ — 2039 11,395 2038 7,053 2037 750 2036 — Total $ 19,198 As of December 31, 2020, the Company had Scientific Research and Experimental Development (“SR&ED”) expenditures of approximately $28.2 million, respectively, for Canadian federal and Quebec purposes, which have not been deducted. These expenditures are available to reduce future taxable income and have an unlimited carryforward period. SR&ED expenditures are subject to verification by the tax authorities and, accordingly, the amounts may vary. As of December 31, 2020, the Company had non-refundable Canadian federal investment tax credits of approximately $4.3 million, which may be utilized to reduce Canadian federal income taxes payable. The Company has not recognized the tax benefits related to the non-refundable investment tax credits. The investment tax credits expire as follows: (in thousands) 2040 $ 1,687 2039 1,362 2038 776 2037 455 2036 24 Total $ 4,304 As at December 31, 2020, the Company had U.S. federal research and development credit carryforwards of approximately $0.8 million, which begin to expire in 2038. As of December 31, 2020, the Company also had U.S. state research and development credit carryforwards of approximately $0.2 million, which expire in 2038. The Company’s deferred tax assets for the years ended December 31, 2020 and 2019 consisted of the following: 2020 2019 (in thousands) Net operating loss carryforwards $ 5,087 $ 8,442 Net research and development expenditures 7,478 4,195 Share issuance costs 4,506 78 Net federal investment tax credits 3,181 1,877 U.S. research and development tax credits 961 — Tax basis of property and equipment in excess of carrying values (86 ) (204 ) Operating lease right-of-use assets (1,240 ) (279 ) Operating lease liability 1,063 287 Accrued expense and other liabilities 345 161 Deferred revenue 15,372 — Share-based compensation 103 — Total deferred tax assets 36,770 14,557 Valuation allowance (35,358 ) (14,425 ) Net deferred tax assets $ 1,412 $ 132 The Company files income tax returns in Canada and in the United States. In the normal course of business, the Company could be subject to examination by federal and provincial or state jurisdictions, where applicable. There are currently no pending tax examinations. The Company may be subject to tax examination for 2016, 2017, 2018, 2019 and 2020 due to unexpired statute of limitation periods. The calculation of the Company’s tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations for both federal taxes and the provinces and states in which the Company operates or does business in. ASC 740 states that a tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, on the basis of the technical merits. The Company records uncertain tax positions as liabilities in accordance with ASC 740 and adjusts these liabilities when the Company’s judgment changes as a result of the evaluation of new information not previously available. Because of the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from the current estimate of the unrecognized tax benefit liabilities. These differences will be reflected as increases or decreases to income tax expense in the period in which new information is available. As of December 31, 2020 and 2019, no uncertain tax positions have been recorded in the consolidated financial statements. The Company recognizes interest and penalties related to unrecognized tax benefits on the income tax expense line in the accompanying consolidated statement of operations and comprehensive loss. As of December 31, 2020 and 2019, no accrued interest or penalties are included on the related tax liability line in the consolidated balance sheet.

Net Loss per Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss per Share	14. Net Loss per Share The following table summarizes the computation of basic and diluted net loss per share attributable to common shareholders of the Company: Year Ended December 31, 2020 2019 (in thousands, except share and per share data) Numerator: Net loss attributable to common shareholders $ (53,417 ) $ (27,216 ) Net loss attributable to common shareholders—basic and diluted $ (53,417 ) $ (27,216 ) Denominator: Weighted-average number of common shares outstanding— basic and diluted 20,045,602 1,528,374 Net loss per share attributable to common shareholders— basic and diluted $ (2.66 ) $ (17.81 ) The Company’s potentially dilutive securities, which include Convertible Preferred Shares and stock options, have been excluded from the computation of diluted net loss per share attributable to common shareholders as the effect would be to reduce the net loss per share attributable to common shareholders. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common shareholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common shareholders for the periods indicated because including them would have had an anti-dilutive effect: Year Ended December 31, 2020 2019 Series A preferred shares — 11,090,135 Series B preferred shares — 10,468,258 Options to purchase common shares 4,132,123 3,505,119

Government Assistance

Government Assistance	12 Months Ended
	Dec. 31, 2020
Research And Development [Abstract]
Government Assistance	15. Government Assistance The Company incurred research and development expenditures which are eligible for investment tax credits. The investment tax credits recorded are based on management’s estimates of amounts expected to be recovered and are subject to audit by the taxation authorities. These amounts have been recorded as a reduction of research and development expenditures for an amount of $0.9 million and $0.6 million for the years ended December 31, 2020 and 2019, respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. Commitments and Contingencies The following table summarizes the Company’s commitments to settle contractual obligations at December 31, 2020, other than leases which are recognized as operating lease liabilities in the consolidated balance sheet. Year Ending December 31, (in thousands) 2021 $ 1,525 2022 2,441 2023 2,325 2024 2,341 2025 25 Total $ 8,657 The commitment amounts in the table above are associated with contracts that are enforceable and legally binding and that specify all significant terms, including fixed or minimum services to be used, fixed, minimum or variable price provisions, and the approximate timing of the actions under the contracts. Collaboration and Research Agreements Collaboration and research agreement obligations primarily relate to a strategic collaboration agreement that was entered into with the University of Texas M. D. Anderson Cancer Center (“MDACC”) in March 2020. The collaboration consists of preclinical studies and clinical trials designed by the Company and MDACC with the research to be completed by MDACC. The Company has agreed to commit $10.0 million in funding for various studies over a period of five years, of which $2.0 million was paid in April 2020. Collaboration and research agreement obligations further relate to an agreement the Company entered into with the Broad Institute, Inc. (“Broad”), in February 2019, under which Broad will perform specialty screening services at the Company’s request over the course of a three-year term in exchange for payments of $0.5 million per year, beginning in February 2019, totaling $1.5 million in the aggregate. Purchase and Other Obligations In the normal course of business, the Company enters into contracts with Contract Research Organizations (“CROs”) and other third parties for preclinical studies and clinical trials, research and development supplies and other testing and manufacturing services. These contracts generally do not contain minimum purchase commitments and provide for termination on 30 to 90 days’ prior written notice, and therefore are cancellable contracts. These payments are not included in the table above as the amount and timing of such payments are not known as of December 31, 2020. In the normal course of business, the Company also entered into a research and development service agreement with a third party, which provides for potential milestone payments by the Company, contingent on the achievement of clinical development milestones. The maximum amount that would be paid if all milestones, however unlikely, are achieved is $1.75 million. This agreement also requires termination payments of up to $0.5 million should the Company cancel the agreement without cause prior to completion of certain research and development services. These payments are not included in the table above as they entail uncertainties in relation to the amount and timing of such payments as they are dependent on milestone achievements or termination. The Company has further entered into license agreements under which it is obligated to make milestone and royalty payments and incur annual maintenance fees. The future milestone or royalty payments under these agreements have not been included in the table above since the payment obligations are contingent upon future events, such as achieving certain clinical and commercial milestones or generating product sales. As of December 31, 2020, the Company is unable to estimate the timing or likelihood of achieving these clinical and commercial milestones or generating future product sales (see Note 7). Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any indemnification arrangements that could have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in these consolidated financial statements as at December 31, 2020.

Currency Risk

Currency Risk	12 Months Ended
	Dec. 31, 2020
Foreign Currency Risk [Abstract]
Currency Risk	17. Currency Risk The Company is exposed to the financial risk related to the fluctuation of foreign exchange rates and the degree of volatility of those rates. The foreign currency risk is limited to the portion of the Company’s business transactions denominated in currency other than USD. The Company incurs a portion of its expenses in Canadian dollars, as well as other currencies to a lesser extent. A change in the currency exchange rates between the USD relative to the Canadian dollar could have a significant effect on the Company’s results of operations, financial position, or cash flows. The Company does not enter into arrangements to hedge its currency risk exposure, although it maintains expected Canadian dollar cash requirements in Canadian dollars to form a natural hedge. The Company is exposed to currency risk through its cash, research and development tax credits receivable, other receivables, accounts payable, accrued expenses and other current liabilities, as well as right-of-use lease liabilities denominated in thousands of Canadian dollars as follows: December 31, 2020 2019 (in thousands) Cash $ 1,715 $ 29,983 Restricted cash 270 270 Research and development tax credits receivable 2,559 1,403 Other receivables 5,228 2,566 Accounts payable (1,322 ) (1,026 ) Accrued expenses and other current liabilities (2,722 ) (283 ) Lease liabilities (4,847 ) (565 ) Net financial position exposure $ 881 $ 32,348 Based on the above net exposure at December 31, 2020, and assuming that all other variables remain constant, a 10% depreciation of the USD against the Canadian dollar would result in an increase of $0.1 million in the Company’s net loss for the year ended December 31, 2020. The Company is also exposed to currency risk through the Ono Agreement as future payments receivable under its collaboration with Ono, if any, are denominated in Japanese yen.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Parties	18. Related Parties Details of transactions between the Company and other related parties are disclosed below and in other notes according to the nature of the transactions. All transactions are measured at the exchange amount, which is the amount of consideration determined and agreed to by the related parties. For the years ended December 31, 2020 and 2019, the Company recorded expenses of $0 and $1.3 million, respectively, for research services and rent paid by the Company to entities affiliated with a shareholder. As of December 31, 2020 and 2019, there was a total of $0 and $0.2 million, respectively, in accounts payable and accrued expenses and other current liabilities owed to an entity affiliated with a shareholder.

Geographic Information

Geographic Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Geographic Information	19. Geographic Information The Company’s property and equipment, net by location as of December 31, 2020 and 2019 was as follows: December 31, 2020 December 31, 2019 (in thousands) Canada $ 3,845 $ 2,279 United States 103 111 Total property and equipment, net $ 3,948 $ 2,390 The Company’s right-of-use assets by location were as follows: December 31, 2020 December 31, 2019 (in thousands) Canada $ 4,483 $ 409 United States 191 625 Total right-of-use assets, net $ 4,674 $ 1,034

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	20. Subsequent Events In February and March 2021, the Company granted an aggregate of 1,141,726 stock options to employees under the 2020 Plan, at a weighted average exercise price of $36.49 per share.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements of the Company include the accounts of the Company and its wholly-owned subsidiary, Repare Therapeutics USA Inc. (“Repare USA”), which was incorporated under the laws of Delaware on June 1, 2017. The financial statements of Repare USA are prepared for the same reporting period as the parent company, using consistent accounting policies. All intra-group transactions, balances, income, and expenses are eliminated in full upon consolidation.
Foreign Currencies	Foreign Currencies The functional currency for the Company and Repare USA is the U.S. dollar (“USD”). Accordingly, transactions denominated in currencies other than the functional currency are measured and recorded in the functional currency at the exchange rate in effect on the date of the transactions. At each consolidated balance sheet date, monetary assets and liabilities denominated in currencies other than the functional currency are remeasured using the exchange rate in effect at that date. Non-monetary assets and liabilities and revenue and expense items denominated in foreign currencies are translated into the functional currency using the exchange rate prevailing at the dates of the respective transactions. Any gains or losses arising on remeasurement are included in the consolidated statement of operations.
Segment Information	Segment Information The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is the research, development and commercialization of precision oncology drugs targeting specific vulnerabilities of tumors in genetically defined patient populations.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in consolidated financial statements and accompanying notes. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, estimates related to revenue recognition, accrued research and development expenses, share-based compensation, right-of-use assets and lease liabilities and income taxes. The Company bases its estimates on historical experience and other market specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results could differ from those estimates. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known.
COVID-19 Pandemic	COVID-19 Pandemic With the global spread of the ongoing COVID-19 pandemic, the Company established a cross-functional task force and has implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on its employees and its business, including its preclinical studies and its ongoing and planned clinical trials. The Company’s operations are considered as an “essential business” and therefore, the Company is continuing to operate during this period. The Company has taken measures to secure its research and development activities, while work in its laboratories and facilities has been re-organized to reduce risk of COVID-19 transmission. While the Company is experiencing limited financial impacts at this time, given the global economic slowdown, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic, the Company’s business, financial condition, and results of operations could be materially adversely affected. The Company continues to closely monitor the COVID-19 pandemic as it evolves its business continuity plans, clinical development plans and response strategy. As of the date of these financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. Actual results could differ from these estimates, and any such differences may be material to the Company’s financial statements.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with original maturities of 90 days or less at acquisition to be cash equivalents. Cash and cash equivalents include cash held in banks and amounts held in money market funds.
Marketable Securities	Marketable Securities The Company classifies marketable debt securities with a remaining maturity of greater than three months when purchased as available-for-sale. Marketable debt securities with a remaining maturity date greater than one year are classified as non-current where the Company has the intent and ability to hold these securities for at least the next 12 months. The Company’s marketable securities consist of U.S. treasury bills with original maturities greater than 90 days. All of the Company’s marketable securities have a contractual maturity of one year or less. The Company considers its investment portfolio of U.S. treasury bills to be available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices. Unrealized gains and losses are reported in accumulated other comprehensive items in shareholders’ equity (deficit). Amortization and accretion of premiums and discounts are recorded in interest income (expense). Realized gains or losses on debt securities are included in other income (expense). If any adjustments to fair value reflect a decline in value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s statement of operations and comprehensive income (loss).
Restricted Cash	Restricted Cash As of December 31, 2020 and 2019, restricted cash consisted of $0.2 million and $0.2 million, respectively, used to secure a letter of credit denominated in a foreign currency for the benefit of the landlord in connection with one of the Company’s lease agreements (Note 8).
Concentrations of Credit Risk and Off-Balance Sheet Risk	Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in accredited financial institutions which may periodically exceed insured limits. The Company deposits its cash in financial institutions that it believes have high credit quality and has not experienced any losses on such accounts and does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company’s exposure to foreign exchange risk is primarily related to fluctuations between the Canadian dollar and the U.S. dollar. There are balances in Canadian dollars which are subject to foreign currency fluctuations relating to the impact of translating to U.S. dollars for financial statement presentation. As of December 31, 2020 and 2019, the Company had no significant off-balance sheet risk, such as foreign exchange contracts, option contracts or other foreign hedging arrangements.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss as well as other changes in shareholders’ equity (deficit) that result from transactions and economic events other than those with shareholders. For each of the years ended December 31, 2020 and 2019, comprehensive loss was equal to net loss.
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value under U.S. GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1 – Quoted prices in active markets for identical assets or liabilities. • Level 2 – Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3 – Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. An entity may choose to measure financial instruments and certain other items at fair value at specified election dates. Subsequent unrealized gains and losses on items for which the fair value option has been elected will be reported in earnings. The estimated fair values of the Company’s cash and cash equivalents, restricted cash, other assets, accounts payable and accrued expenses and other current liabilities approximate their carrying values. The Company’s marketable securities are carried at fair value, determined according to Level 1 inputs in the fair value hierarchy described above. The Company’s Series A Preferred Share Tranche Obligation liabilities are carried at fair value, determined according to Level 3 inputs in the fair value hierarchy described above. In January 2019, in connection with the closing of the second tranche of Series A Preferred Shares, the liability related to the Series A second tranche obligation was settled. In September 2019, in connection with the Company’s issuance and sale of Series B Preferred Shares, the liability related to the Series A third tranche obligation was terminated (see Notes 3 and 9).
Property and Equipment, Net	Property and Equipment, Net Property and equipment is stated at historical cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Category Estimated Useful Lives Computer equipment 3 years Office equipment 5 years Laboratory equipment 5 years Leasehold improvements the shorter of the lease term and the useful life When assets are retired or disposed of, the assets and related accumulated depreciation are derecognized from the accounts, and any resulting gain or loss is included in the determination of net loss. Expenditures for maintenance and repairs are recorded to expense as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates its finite-lived intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value of assets may not be recoverable. Recoverability of these assets is measured by comparing their carrying value to the future net undiscounted cash flows the assets are expected to generate over their remaining economic life. If such assets are considered impaired, the impairment to be recognized is measured by the amount by which the carrying value of the assets exceeds their fair value. Indefinite-lived intangible assets are tested for impairment annually, or more frequently if indicators of impairment are present. To date, no such impairment losses have been recorded.
Leases	Leases At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the consolidated balance sheet as a right-of-use asset and current and non-current lease liabilities, as applicable. Operating lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments, which reflects the fixed rate at which the Company could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the right-of-use assets for straight-line rent expense or any incentives received and remeasure the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification grants the lessee an additional right of use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right of use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease. In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets and allocate all of the contract consideration to the lease component only.
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under ASC 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. The Company enters into collaboration and license agreements, which are within the scope of ASC 606, to discover, develop, manufacture, and commercialize product candidates. The terms of these agreements typically contain multiple promises or obligations, which may include: (i) licenses to compounds directed to specific targets (referred to as “exclusive licenses”) and (ii) research and development activities to be performed on behalf of the collaboration partner related to the licensed targets. Payments to the Company under these agreements may include non-refundable license fees, customer option exercise fees, payments for research activities, reimbursement of certain costs, payments based upon the achievement of certain milestones and royalties on any resulting net product sales. The Company first evaluates license and/or collaboration arrangements to determine whether the arrangement (or part of the arrangement) represents a collaborative arrangement pursuant to ASC 808, Collaborative Arrangements (“ASC 808”), based on the risks and rewards and activities of the parties pursuant to the contractual arrangement. The Company accounts for collaborative arrangements (or elements within the contract that are deemed part of a collaborative arrangement), which represent a collaborative relationship and not a customer relationship, outside the scope of ASC 606. The Company’s collaborations primarily represent revenue arrangements. For the arrangements or arrangement components that are subject to revenue accounting guidance, in determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company applies the five-step model. As part of the accounting for these arrangements, the Company must use significant judgment to determine: a) the number of performance obligations based on the determination under step (ii) above and whether those performance obligations are distinct from other performance obligations in the contract; b) the transaction price under step (iii) above; and c) the stand-alone selling price for each performance obligation identified in the contract for the allocation of transaction price in step (iv) above. The Company uses judgment to determine whether milestones or other variable consideration, except for sales-based royalties, should be included in the transaction price as described further below. The transaction price is allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. In determining the stand-alone selling price of a license to the Company’s proprietary technology or a material right provided by a customer option, the Company considers market conditions as well as entity-specific factors, including those factors contemplated in negotiating the agreements as well as internally developed estimates that include assumptions related to the market opportunity, estimated development costs, probability of success and the time needed to commercialize a product candidate pursuant to the license. In validating its estimated stand-alone selling price, the Company evaluates whether changes in the key assumptions used to determine its estimated stand-alone selling price will have a significant effect on the allocation of arrangement consideration between performance obligations. Amounts received prior to revenue recognition are recorded as deferred revenue. Amounts expected to be recognized as revenue within one year following the balance sheet date are classified as current portion of deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized as revenue within one year following the balance sheet date are classified as deferred revenue, net of current portion. Amounts recognized as revenue, but not yet received or invoiced are generally recognized as contract assets. Exclusive Licenses – If the license to the Company’s intellectual property is determined to be distinct from the other promises or performance obligations identified in the arrangement, which generally include research and development services, the Company recognizes revenue from non-refundable, upfront fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. In assessing whether a license is distinct from the other promises, the Company considers relevant facts and circumstances of each arrangement, including the research and development capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. In addition, the Company considers whether the collaboration partner can benefit from the license for its intended purpose without the receipt of the remaining promises, whether the value of the license is dependent on the unsatisfied promises, whether there are other vendors that could provide the remaining promises and whether it is separately identifiable from the remaining promises. For licenses that are combined with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation and whether the license is the predominant promise within the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. If the license is the predominant promise, and it is determined that the license represents functional intellectual property (“IP”), revenue is recognized at the point in time when control of the license is transferred. If it is determined that the license does not represent functional IP, revenue is recognized over time using an appropriate method of measuring progress. Research and Development Services – The obligations under the Company’s collaboration and license agreements generally include research and development services to be performed by the Company to benefit the collaboration partner. For performance obligations that include research and development services, the Company generally recognizes revenue allocated to such performance obligations based on an appropriate measure of progress. The Company utilizes judgment to determine the appropriate method of measuring progress for purposes of recognizing revenue, which is generally an input measure such as costs incurred. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. The measure of progress, and thereby periods of which revenue should be recognized, are subject to estimates by management and may change over the course of the contract. Reimbursements from the partner that are the result of a collaborative relationship with the partner, instead of a customer relationship, such as co-development activities, are recorded as a reduction to research and development expense. Customer Options – The Company’s arrangements may provide a collaborator with the right to acquire additional goods or services in the future. Under these agreements, fees may be due to the Company (i) at the inception of the arrangement as an upfront fee or payment or (ii) upon the exercise of the customer option. If an arrangement is determined to contain customer options that allow the customer to acquire additional goods or services, the goods and services underlying the customer options are not considered to be performance obligations at the outset of the arrangement, as they are contingent upon option exercise. The Company evaluates the customer options for material rights, or options to acquire additional goods or services for free or at a discount. If the customer options are determined to represent a material right, the material right is recognized as a separate performance obligation at the inception of the arrangement. The Company allocates the transaction price to material rights based on the relative stand-alone selling price, which is determined based on the identified discount and the probability that the customer will exercise the option. Amounts allocated to a material right are not recognized as revenue until, at the earliest, the option is exercised or expires. Milestone Payments – At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being achieved and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The Company evaluates factors such as the scientific, clinical, regulatory, commercial, and other risks that must be overcome to achieve the particular milestone in making this assessment. There is considerable judgment involved in determining whether it is probable that a significant revenue reversal would not occur. At the end of each subsequent reporting period, the Company reevaluates the probability of achievement of all milestones subject to constraint and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. If a milestone or other variable consideration relates specifically to the Company’s efforts to satisfy a single performance obligation or to a specific outcome from satisfying the performance obligation, the Company generally allocates the milestone amount entirely to that performance obligation once it is probable that a significant revenue reversal would not occur. Royalties – For arrangements that include sales-based royalties, including milestone payments based on a level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of its licensing arrangements. For a complete discussion of accounting for collaboration revenues, see Note 12.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred. The Company’s research and development expenses consist primarily of costs incurred in performing research and development activities, including salaries and other compensation, share-based compensation, fees paid to external service providers, laboratory supplies and costs for facilities and equipment, partially offset by fully refundable research and development tax credits. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are expensed as the goods are delivered or the services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company has entered into various research and development contracts. The payments to these agreements are recorded as research and development expenses as incurred. The Company records accrued liabilities for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgements and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates.
Share-Based compensation	Share-Based compensation The Company accounts for all share-based awards granted to employees and non-employees as share-based compensation expense at fair value. Since the Company’s IPO in June 2020, the fair value of the underlying common shares is based on the trading price of the Company’s common shares. Prior to the Company’s IPO, the Company previously engaged an independent valuation firm to determine the fair value of the underlying common shares. The independent valuation firm used valuation techniques and methods that comply with guidance provided by the American Institute of Certified Public Accountants in its Accounting & Valuation Guide. Each valuation methodology included estimates and assumptions that required the Company’s judgment. These estimates and assumptions included a number of objective and subjective factors in determining the value of the Company’s common shares at each grant date, including: (1) prices paid for the Company’s convertible preferred shares, which the Company has sold to outside investors in arm’s-length transactions, and the rights, preferences and privileges of the Company’s convertible preferred shares and common shares; (2) valuations performed by an independent valuation specialist; (3) the Company’s stage of development; (4) the fact that grants of share-based awards involved illiquid securities in a private company; and (5) the likelihood of achieving a liquidity event for the common shares underlying the share-based awards, such as an initial public offering or sale of the Company, given prevailing market conditions. The measurement date for employee and non-employee awards is the date of grant, and share-based compensation costs are recognized over the employees’ requisite service period, which is the vesting period, on a straight-line basis. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected share price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option and the Company’s expected dividend yield. As there was no public market for its common shares prior to its IPO, the Company determined the volatility for awards granted based on an analysis of reported data for a group of guideline companies that issued options with substantially similar terms. The expected volatility has been determined using a weighted-average of the historical volatility measures of this group of guideline companies. The Company expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded share price. The expected term of the Company’s stock options granted to employees and non-employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. In connection with the adoption of ASU No. 2018-07, Compensation—Stock Compensation (“ASU No. 2018-07”), the Company calculated the expected term of non-employee awards using the midpoint between the vesting date and the contractual term, which is consistent with the method used for employee awards. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. The Company has not paid, and does not anticipate paying, cash dividends on its common shares; therefore, the expected dividend yield is assumed to be zero. Share-based compensation is classified in the accompanying consolidated statements of operations and comprehensive loss based on the function to which the related services are provided. Forfeitures are accounted for as they occur. Any consideration paid by employees on exercising stock options and the corresponding portion previously credited to additional paid-in capital are credited to share capital.
Classification of Convertible Preferred Shares	Classification of Convertible Preferred Shares The Company’s convertible preferred shares were classified outside of shareholders’ deficit because the holders of such shares had liquidation rights in the event of a deemed liquidation that, in certain situations, was not solely within the control of the Company. The Company recorded convertible preferred shares at fair value upon issuance, net of any issuance costs or discounts.
Share Issuance Costs	Share Issuance Costs Share issuance costs applicable to the issuance of equity instruments are recorded as a reduction of the financing equity proceeds.
Net Loss per Share	Net Loss per Share Basic net loss per share attributable to common shareholders is computed by dividing the net loss attributable to common shareholders by the weighted-average number of common shares outstanding during the reporting period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common shareholders by the weighted-average number of common shares and potentially dilutive securities outstanding during the period determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, convertible preferred shares and stock options considered to be potentially dilutive securities were excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore, basic and diluted net loss per share were the same for all reporting periods presented.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on differences between the consolidated financial statement carrying amounts and the tax bases of the assets and liabilities using the enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Research and Development Tax Credits	Research and Development Tax Credits The Company recognizes the benefit of refundable Canadian research and development tax credits as a reduction of research and development costs when there is reasonable assurance that the amount claimed will be recovered.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. Section 107 of the JOBS Act provides that an emerging growth company can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, its consolidated financial statements may not be comparable to companies that comply with public company effective dates. The Company may take advantage of these exemptions up until December 31, 2025 or such earlier time that it is no longer an emerging growth company.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808) – Clarifying the Interaction between Topic 808 and Topic 606 (“ASU No. 2018-18”). The amendments in ASU 2018-18 clarify that certain transactions between collaborative arrangement participants should be accounted for as revenue under ASC 606 when the collaborative arrangement participant is a customer in the context of a unit of account. The amendments under ASU 2018-18 are effective for interim and annual fiscal periods beginning after December 15, 2019, with early adoption permitted. The amendments in ASU 2018-18 should be applied retrospectively to the date of initial application of ASC 606. The adoption of ASU 2018-18 did not have a material impact on the Company’s consolidated financial statements.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes-Simplifying the Accounting for Income Taxes (“ASU No. 2019-12”). ASU No. 2019-12 eliminates certain exceptions related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. For public entities, ASU No. 2019-12 is effective for annual periods beginning after December 15, 2020, including interim periods within. For all other entities, this pronouncement is effective for fiscal years beginning after December 15, 2021, including interim periods within fiscal years beginning after December 15, 2022. Early adoption is permitted for all entities. Adoption of the standard requires certain changes to be made prospectively, with some changes to be made retrospectively. The Company is currently assessing the impact of this standard on its financial condition and results of operations.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Property and Equipment	Property and equipment is stated at historical cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Category Estimated Useful Lives Computer equipment 3 years Office equipment 5 years Laboratory equipment 5 years Leasehold improvements the shorter of the lease term and the useful life

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of December 31, 2020: Description December 31, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Observable Inputs (Level 3) (in thousands) Assets Cash equivalents Money market funds $ 2,455 $ 2,455 $ — $ — Marketable securities U.S. Treasury notes 7,526 7,526 — — Total financial assets $ 9,981 $ 9,981 $ — $ —
Schedule of Aggregate Fair Value of Series A Preferred Share Tranche Obligation using Level 3 Inputs	The following table provides a roll forward of the aggregate fair value of the Company’s Series A Preferred Share Tranche Obligation for which fair value was determined using Level 3 inputs: Series A Preferred Share Tranche Obligation (in thousands) Balance as of December 31, 2018 $ 2,490 Change in fair value 1,350 Tranche 2 settlement of obligation (880 ) Tranche 3 termination (2,960 ) Balance as of December 31, 2019 $ —

Cash and Cash Equivalents and_2

Cash and Cash Equivalents and Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Summary of Cash and Cash Equivalents and Marketable Securities	As of December 31, 2020, cash and cash equivalents and marketable securities were comprised of the following: Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) As at December 31, 2020 Money market funds included in cash and cash equivalents $ 2,455 $ — $ — $ 2,455 Marketable securities: U.S. Treasury notes 7,526 — — 7,526 Total $ 9,981 $ — $ — $ 9,981

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 (in thousands) Computer equipment $ 301 $ 256 Office equipment 216 177 Laboratory equipment 4,718 2,565 Leasehold improvements 706 488 Total 5,941 3,486 Less: Accumulated depreciation (1,993 ) (1,096 ) Property and equipment, net $ 3,948 $ 2,390

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities as of December 31, 2020 and 2019 consisted of the following: December 31, 2020 2019 (in thousands) Accrued compensation and benefits $ 2,771 $ 1,043 Accrued research and development expense 2,584 208 Accrued professional services 436 21 Other 184 4 Total accrued expenses and other current liabilities $ 5,975 $ 1,276

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Summary of Lease Costs	The following tables contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the years ended December 31, 2020 and 2019: December 31, 2020 December 31, 2019 (in thousands) Operating Leases Lease Cost Operating lease cost $ 999 $ 411 Short-term lease cost 51 12 Variable lease cost 161 248 Total lease cost $ 1,211 $ 671
Summary of Other Operating Lease Information	December 31, 2020 December 31, 2019 Other Operating Lease Information (in thousands, except as specified otherwise) Operating cash flows for operating leases $ 802 $ 426 Right-of-use assets obtained in exchange for new operating lease liability $ 4,538 $ 1,074 Weighted-average remaining lease term 4.5 years 1.79 years Weighted-average discount rate 5.1 % 7.6 %
Summary of Future Minimum Lease Payments under Operating Leases	Future minimum lease payments under the Company’s operating leases as of December 31, 2020 were as follows: December 31, 2020 (in thousands) Maturity of Lease Liabilities 2021 $ 871 2022 780 2023 1,053 2024 1,069 2025 720 Total lease payments $ 4,493 Less: interest (488 ) Total lease liabilities $ 4,005

Convertible Preferred Shares (T

Convertible Preferred Shares (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Summary of Preferred Shares	As of December 31, 2019, preferred shares consisted of the following in the table below: December 31, 2019 Preferred Shares Issued and Outstanding Carrying Value Liquidation Value Common Shares Issuable Upon Conversion (in thousands, except share amounts) Series A Preferred Shares 11,090,135 $ 53,749 $ 52,750 11,090,135 Series B Preferred Shares 10,468,258 82,248 82,496 10,468,258 21,558,393 $ 135,997 $ 135,246 21,558,393

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Fair Value of Stock Options Determined on Grant Date Using Black Scholes Option-Pricing Model	The assumptions that the Company used in the Black Scholes option-pricing model to determine the grant date fair value of stock options granted to employees and non-employees were as follows, presented on a weighted-average basis: Year Ended December 31, 2020 2019 Risk-free interest rate 0.45 % 1.94 % Expected term (in years) 6.07 6.10 Expected volatility 72.26 % 71.41 % Expected dividend yield 0.00 % 0.00 %
Schedule of Stock Option Activity	The following table summarizes the Company’s stock option activity: 2020 2019 Number of shares Weighted average exercise price Weighted average remaining contractual term (in years) Intrinsic value (in thousands) Number of shares Weighted average exercise price Weighted average remaining contractual term (in years) Outstanding, January 1 3,505,119 $ 2.07 8.98 907,315 $ 1.66 8.55 Granted 1,083,274 $ 18.57 2,761,034 $ 2.21 Exercised (416,157 ) $ 1.92 - $ - Forfeited (40,113 ) $ 3.91 (163,230 ) $ 2.06 Outstanding, December 31 4,132,123 $ 6.39 8.64 $ 115,328 3,505,119 $ 2.07 8.98 Options exercisable, December 31 1,217,497 $ 1.96 7.87 $ 39,374 611,927 $ 1.69 6.75 Options unvested, December 31 2,914,626 $ 8.25 8.96 $ 75,926 2,893,192 $ 2.15 9.45
Schedule of Share-based Compensation Expense	Share-based compensation expense was allocated as follows: Year Ended December 31, 2020 2019 (in thousands) Research and development $ 890 $ 250 General and administrative 1,647 261 Total share-based compensation expense $ 2,537 $ 511

Collaborations (Tables)

Collaborations (Tables)	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Transaction Price Performance Obligations	Based on the relative stand-alone selling price, the allocation of the transaction price to the separate performance obligations was as follows: Performance obligation Transaction price (in thousands) Research activities 6,405 Options to license druggable targets 31,148 Options to license undruggable targets 12,447 Total transaction price 50,000

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Summary of Loss Before Provision for Income Taxes	Loss before the provision for income taxes for the years ended December 31, 2020 and 2019 consisted of the following: Year Ended December 31, 2020 2019 (in thousands) Canada $ (55,446 ) $ (27,355 ) Foreign $ 704 $ 334 $ (54,742 ) $ (27,021 )
Summary of Reconciliation of Provision for Income Taxes	A reconciliation between tax expense and the product of accounting income multiplied by the statutory income tax rate for years ended December 31, 2020 and 2019 is as follows: Year Ended December 31, 2020 2019 (in thousands) Loss before income taxes $ (54,742 ) $ (27,021 ) Income tax at statutory rate 26.5 % 26.5 % Computed income tax recovery (14,507 ) (7,160 ) Effect on income tax resulting from: Federal investment tax credit (2,347 ) (985 ) Accounting charges not deductible for tax purposes 346 277 Other (306) (16 ) Change in valuation allowance 15,489 8,079 Tax (benefit) expense $ (1,325 ) $ 195
Summary of Losses Expire	The Company has not recognized the tax benefit of these losses. These losses expire as follows: (in thousands) 2040 $ — 2039 11,395 2038 7,053 2037 750 2036 — Total $ 19,198
Summary of Investment Tax Credits Expire	The Company has not recognized the tax benefits related to the non-refundable investment tax credits. The investment tax credits expire as follows: (in thousands) 2040 $ 1,687 2039 1,362 2038 776 2037 455 2036 24 Total $ 4,304
Summary of Deferred Tax Assets	The Company’s deferred tax assets for the years ended December 31, 2020 and 2019 consisted of the following: 2020 2019 (in thousands) Net operating loss carryforwards $ 5,087 $ 8,442 Net research and development expenditures 7,478 4,195 Share issuance costs 4,506 78 Net federal investment tax credits 3,181 1,877 U.S. research and development tax credits 961 — Tax basis of property and equipment in excess of carrying values (86 ) (204 ) Operating lease right-of-use assets (1,240 ) (279 ) Operating lease liability 1,063 287 Accrued expense and other liabilities 345 161 Deferred revenue 15,372 — Share-based compensation 103 — Total deferred tax assets 36,770 14,557 Valuation allowance (35,358 ) (14,425 ) Net deferred tax assets $ 1,412 $ 132

Net Loss per Share (Tables)

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share Attributable To Common Shareholders	The following table summarizes the computation of basic and diluted net loss per share attributable to common shareholders of the Company: Year Ended December 31, 2020 2019 (in thousands, except share and per share data) Numerator: Net loss attributable to common shareholders $ (53,417 ) $ (27,216 ) Net loss attributable to common shareholders—basic and diluted $ (53,417 ) $ (27,216 ) Denominator: Weighted-average number of common shares outstanding— basic and diluted 20,045,602 1,528,374 Net loss per share attributable to common shareholders— basic and diluted $ (2.66 ) $ (17.81 )
Computation of Diluted Net Loss Per Share in Attributable to Common Shareholders Indicate to Anti Diluted Effect	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common shareholders for the periods indicated because including them would have had an anti-dilutive effect: Year Ended December 31, 2020 2019 Series A preferred shares — 11,090,135 Series B preferred shares — 10,468,258 Options to purchase common shares 4,132,123 3,505,119

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Schedule of Commitments to Settle Contractual Obligations	The following table summarizes the Company’s commitments to settle contractual obligations at December 31, 2020, other than leases which are recognized as operating lease liabilities in the consolidated balance sheet. Year Ending December 31, (in thousands) 2021 $ 1,525 2022 2,441 2023 2,325 2024 2,341 2025 25 Total $ 8,657

Currency Risk (Tables)

Currency Risk (Tables)	12 Months Ended
	Dec. 31, 2020
Foreign Currency Risk [Abstract]
Schedule of Financial Position Exposure	The Company is exposed to currency risk through its cash, research and development tax credits receivable, other receivables, accounts payable, accrued expenses and other current liabilities, as well as right-of-use lease liabilities denominated in thousands of Canadian dollars as follows: December 31, 2020 2019 (in thousands) Cash $ 1,715 $ 29,983 Restricted cash 270 270 Research and development tax credits receivable 2,559 1,403 Other receivables 5,228 2,566 Accounts payable (1,322 ) (1,026 ) Accrued expenses and other current liabilities (2,722 ) (283 ) Lease liabilities (4,847 ) (565 ) Net financial position exposure $ 881 $ 32,348

Geographic Information (Tables)

Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Property and Equipment, Net and Right-of-Use Assets by Location	The Company’s property and equipment, net by location as of December 31, 2020 and 2019 was as follows: December 31, 2020 December 31, 2019 (in thousands) Canada $ 3,845 $ 2,279 United States 103 111 Total property and equipment, net $ 3,948 $ 2,390 The Company’s right-of-use assets by location were as follows: December 31, 2020 December 31, 2019 (in thousands) Canada $ 4,483 $ 409 United States 191 625 Total right-of-use assets, net $ 4,674 $ 1,034

Organization and Nature of Bu_2

Organization and Nature of Business - Additional Information (Details) $ in Thousands	Jun. 23, 2020USD ($)shares	Jun. 12, 2020	Jun. 30, 2020shares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)
Organization and Nature of Business [Line Items]
Entity incorporation, date of incorporation				Sep. 6, 2016
Reverse stock split of share capital				1-for-6.062
Conversion ratio		0.16496
Net proceeds from IPO | $				$ 232,043
Accumulated deficit | $				$ (103,358)	$ (49,941)
Common Shares
Organization and Nature of Business [Line Items]
Gross proceeds from IPO | $	$ 253,000
Net proceeds from IPO | $	$ 232,043
Convertible preferred shares converted into common shares | shares	21,558,393		21,558,393	21,558,393
Shares issued upon exercise of warrants outstanding | shares	750,000
Common Shares | Initial Public Offering
Organization and Nature of Business [Line Items]
Shares issued | shares	12,650,000			12,650,000
Common Shares | Exercise of Underwriters Option
Organization and Nature of Business [Line Items]
Shares issued | shares	1,650,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Restricted cash	$ 212,000	$ 208,000
Significant off-balance sheet risk, description	As of December 31, 2020 and 2019, the Company had no significant off-balance sheet risk, such as foreign exchange contracts, option contracts or other foreign hedging arrangements.
Impairment of long-lived assets	$ 0
Share based compensation, expected dividend yield assumed	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Computer Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of assets	3 years
Office Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of assets	5 years
Laboratory Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of assets	5 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated useful lives of assets, description	the shorter of the lease term and the useful life

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Assets
Total financial assets		$ 0
Fair Value Measurements, Recurring
Assets
Total financial assets	$ 9,981,000
Fair Value Measurements, Recurring | U.S. Treasury Notes
Assets
Total financial assets	7,526,000
Fair Value Measurements, Recurring | Quoted Prices in Active Markets for identical Assets (Level 1)
Assets
Total financial assets	9,981,000
Fair Value Measurements, Recurring | Quoted Prices in Active Markets for identical Assets (Level 1) | U.S. Treasury Notes
Assets
Total financial assets	7,526,000
Fair Value Measurements, Recurring | Money Market Funds
Assets
Total financial assets	2,455,000
Fair Value Measurements, Recurring | Money Market Funds | Quoted Prices in Active Markets for identical Assets (Level 1)
Assets
Total financial assets	$ 2,455,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair value, assets, transfers between levels		$ 0
Financial assets	$ 0
Financial liabilities	0
Change in fair value of Series A Preferred Shares tranche obligation recorded in other expense	$ 1,350,000

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Aggregate Fair Value of Series A Preferred Share Tranche Obligation using Level 3 Inputs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Change in fair value	$ 1,350
Series A Preferred Share Tranche Obligation | Level 3 Inputs
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	2,490
Change in fair value	1,350
Tranche 2 settlement of obligation	(880)
Tranche 3 termination	$ (2,960)

Cash and Cash Equivalents and_3

Cash and Cash Equivalents and Marketable Securities - Summary of Cash and Cash Equivalents and Marketable Securities (Details)	Dec. 31, 2020USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 9,981,000
Unrealized Gains	0
Unrealized Losses	0
Fair Value	9,981,000
U.S. Treasury Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	7,526,000
Unrealized Gains	0
Unrealized Losses	0
Fair Value	7,526,000
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	2,455,000
Unrealized Gains	0
Unrealized Losses	0
Fair Value	$ 2,455,000

Cash and Cash Equivalents and_4

Cash and Cash Equivalents and Marketable Securities - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Unrealized gains	$ 0
Unrealized losses	$ 0
Money market funds		$ 0
Marketable securities		$ 0

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,941	$ 3,486
Less: Accumulated depreciation	(1,993)	(1,096)
Property and equipment, net	3,948	2,390
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	301	256
Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	216	177
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	4,718	2,565
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 706	$ 488

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Depreciation expense	$ 897	$ 605
Research and Development Expense
Property Plant And Equipment [Line Items]
Depreciation expense	800	500
General and Administrative Expense
Property Plant And Equipment [Line Items]
Depreciation expense	$ 100	$ 100

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 2,771	$ 1,043
Accrued research and development expense	2,584	208
Accrued professional services	436	21
Other	184	4
Total accrued expenses and other current liabilities	$ 5,975	$ 1,276

License Agreements - Additional

License Agreements - Additional Information (Detail) - NYU Agreement - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement milestone and royalty payments upon achievement of certain clinical and commercial milestones	$ 6,700,000	$ 6,700,000
Accrual of potential future milestone or royalty payment		$ 0	$ 0

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Jun. 30, 2019	Nov. 30, 2017	Jun. 30, 2017	Dec. 31, 2020USD ($)Lease	Nov. 30, 2019USD ($)
Lessee Lease Description [Line Items]
Number of operating leases | Lease				4
Lessee, operating lease, existence of option to terminate				false
Implicit interest rate				0.00%
Office and Laboratory Space | Montreal, Quebec
Lessee Lease Description [Line Items]
Operating lease, term of contract		3 years	4 years		5 years
Operating lease, expiration month and year		2020-10	2021-07
Operating lease, existence of option to extend		true
Operating lease, option to extend, description		extended through October 2022
Prepaid rent					$ 1,000
Operating Lease, renewal term					5 years
Office and Laboratory Space | Cambridge, Massachusetts
Lessee Lease Description [Line Items]
Operating lease, term of contract	2 years
Operating lease, expiration month and year	2021-05
Standby Letters of Credit | Office and Laboratory Space | Montreal, Quebec
Lessee Lease Description [Line Items]
Line of credit facility, unused amount				$ 212

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease Cost
Operating lease cost	$ 999	$ 411
Short-term lease cost	51	12
Variable lease cost	161	248
Total lease cost	$ 1,211	$ 671

Leases - Summary of Other Opera

Leases - Summary of Other Operating Lease Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating cash flows for operating leases	$ 802	$ 426
Right-of-use assets obtained in exchange for new operating lease liability	$ 4,538	$ 1,074
Weighted-average remaining lease term	4 years 6 months	1 year 9 months 14 days
Weighted-average discount rate	5.10%	7.60%

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Lease Payments under Operating Leases (Details) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 871
2022	780
2023	1,053
2024	1,069
2025	720
Total lease payments	4,493
Less: interest	(488)
Total lease liabilities	$ 4,005

Convertible Preferred Shares -

Convertible Preferred Shares - Additional Information (Details)	Jun. 23, 2020shares	Jun. 30, 2020shares	Sep. 30, 2019USD ($)$ / sharesshares	Aug. 31, 2019	Jan. 31, 2019USD ($)$ / sharesshares	Jun. 30, 2017USD ($)Tranche$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Temporary Equity [Line Items]
Conversion of convertible preferred shares into an equivalent number of common shares, Value							$ 135,997,000
Preferred shares, noncumulative dividends							8.00%
Preferred stock, conversion basis							The preferred shares were convertible into common shares on a one-to-one basis.
Common Shares
Temporary Equity [Line Items]
Conversion of convertible preferred shares into an equivalent number of common shares, Value							$ 135,997,000
Conversion of convertible preferred shares into an equivalent number of common shares, Shares | shares							21,558,393
Convertible preferred shares converted into common shares | shares	21,558,393	21,558,393					21,558,393
Threshold price per share in initial public offering that triggers automatic conversion of preferred convertible shares into common shares | $ / shares							$ 15.76
Threshold gross proceeds of initial public offering that triggers automatic conversion of preferred convertible shares into common shares							$ 50,000,000
Minimum
Temporary Equity [Line Items]
Percentage of liquidation rights waived by holder of preferred shares							70.00%
Minimum | Common Shares
Temporary Equity [Line Items]
Percentage of holder of preferred shares election to convert the preferred shares							70.00%
Series A Preferred Shares
Temporary Equity [Line Items]
Temporary equity shares authorized						unlimited
Number of tranches | Tranche						3
Beneficial conversion feature							$ 0
Series A Preferred Shares | First Tranche
Temporary Equity [Line Items]
Temporary equity par value | $ / shares						$ 4.91
Issuance of convertible preferred shares, net of issuance costs, Shares | shares						5,906,049
Proceeds from Issuance of convertible preferred stock						$ 29,000,000
Stock issuance costs						40,000
Conversion of convertible preferred shares into an equivalent number of common shares, Value						$ 4,500,000
Conversion of convertible preferred shares into an equivalent number of common shares, Shares | shares						907,291,000
Series A Preferred Shares | Second Tranche
Temporary Equity [Line Items]
Temporary equity par value | $ / shares					$ 4.91
Issuance of convertible preferred shares, net of issuance costs, Shares | shares					4,276,795
Proceeds from Issuance of convertible preferred stock					$ 21,000,000
Series A Preferred Shares | Maximum
Temporary Equity [Line Items]
Issuance of convertible preferred shares, net of issuance costs, Shares | shares						13,237,696
Series A Preferred Shares | Maximum | First Tranche
Temporary Equity [Line Items]
Issuance of convertible preferred shares, net of issuance costs, Shares | shares						7,331,647
Series B Preferred Shares
Temporary Equity [Line Items]
Temporary equity shares authorized				unlimited
Temporary equity par value | $ / shares			$ 7.88
Issuance of convertible preferred shares, net of issuance costs, Shares | shares			10,468,258
Proceeds from Issuance of convertible preferred stock			$ 82,500,000
Beneficial conversion feature							$ 0

Convertible Preferred Shares _2

Convertible Preferred Shares - Summary of Preferred Shares (Details) $ in Thousands	Dec. 31, 2019USD ($)shares
Temporary Equity [Line Items]
Temporary equity shares issued	21,558,393
Temporary equity shares outstanding	21,558,393
Carrying Value | $	$ 135,997
Temporary equity, liquidation and redemption value | $	$ 135,246
Common Shares Issuable Upon Conversion	21,558,393
Series A Preferred Shares
Temporary Equity [Line Items]
Temporary equity shares issued	11,090,135
Temporary equity shares outstanding	11,090,135
Carrying Value | $	$ 53,749
Temporary equity, liquidation and redemption value | $	$ 52,750
Common Shares Issuable Upon Conversion	11,090,135
Series B Preferred Shares
Temporary Equity [Line Items]
Temporary equity shares issued	10,468,258
Temporary equity shares outstanding	10,468,258
Carrying Value | $	$ 82,248
Temporary equity, liquidation and redemption value | $	$ 82,496
Common Shares Issuable Upon Conversion	10,468,258

Shareholders' Equity (Deficit)

Shareholders' Equity (Deficit) - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 23, 2020	May 26, 2020	Jun. 30, 2020	May 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Preferred stock shares authorized					Unlimited
Preferred stock shares issued					0	0
Preferred stock shares outstanding					0	0
Proceeds from issuance of warrant					$ 15,000
Net proceeds from issuance of common shares in initial public offering					$ 232,043
Common stock shares issued					36,902,924	1,528,374
2020 Employee Share Purchase Plan
Class Of Stock [Line Items]
Shares of common stock reserved for future issuance			696,029
Annual increase in number of shares available for issuance as percentage of outstanding shares common stock on final day of preceding calendar year			1.00%
Annual increase in number of shares available for issuance maximum number of common stock issued			3,300,000
Purchase price of shares as percentage of fair market value of common stock on date of purchase			85.00%
Common stock shares issued			0		0
Maximum | 2020 Employee Share Purchase Plan
Class Of Stock [Line Items]
Shares of common stock reserved for future issuance			327,000
Affiliate of Bristol Myers Squibb
Class Of Stock [Line Items]
Proceeds from issuance of warrant		$ 15,000		$ 15,000
Affiliate of Bristol Myers Squibb | Initial Public Offering
Class Of Stock [Line Items]
Warrant exercise price per share	$ 20
Common Shares
Class Of Stock [Line Items]
Convertible preferred shares converted into common shares	21,558,393		21,558,393		21,558,393
Shares issued upon exercise of warrants outstanding	750,000
Shares issued, price per share	$ 20
Gross proceeds from IPO	$ 253,000
Net proceeds from issuance of common shares in initial public offering	$ 232,043
Common Shares | Initial Public Offering
Class Of Stock [Line Items]
Issuance of common shares upon initial public offering, net of issuance costs , Shares	12,650,000				12,650,000
Common Shares | Exercise of Underwriters Option
Class Of Stock [Line Items]
Issuance of common shares upon initial public offering, net of issuance costs , Shares	1,650,000
Common Shares | Exercise of Underwriters Option | Maximum
Class Of Stock [Line Items]
Issuance of common shares upon initial public offering, net of issuance costs , Shares	1,650,000
Common Shares | Affiliate of Bristol Myers Squibb
Class Of Stock [Line Items]
Shares issued upon exercise of warrants outstanding	750,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2021	Jun. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of stock options granted	$ 11.73	$ 1.27
Intrinsic value of options exercised	$ 5,700
Fair value of options vested	$ 1,300	$ 300
Number of options exercised	416,157
Exercised options, weighted-average exercise price	$ 1.92
Aggregate proceeds from exercise of options	$ 799
Decrease in additional paid-in capital as exercised options credited to common shares	500
Unrecognized share-based compensation expense related to unvested stock options	$ 13,600	$ 3,600
Unrecognized share-based compensation expense related to unvested stock options, weighted average period	2 years 7 months 6 days	3 years 2 months 12 days
Common Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options exercised	416,157
Option Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance				298,605
Option Plan | Common Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized to be issued	4,074,135
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase in number of shares available for issuance as percentage of outstanding shares common stock on final day of preceding calendar year	5.00%
Exercise price per share as minimum percentage of fair value of common share	100.00%
Expiration period	10 years
Monthly vesting rate	1/36th
2020 Equity Incentive Plan | Vesting on First Anniversary Date of Grant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage	25.00%
2020 Equity Incentive Plan | Vesting on Monthly Basis at Rate of 1/36th
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage	75.00%
2020 Equity Incentive Plan | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance			5,780,864
2020 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock initially reserved for future issuance				3,600,000
Shares of common stock reserved for future issuance				3,807,448

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Fair Value of Stock Options Determined on Grant Date Using Black Scholes Option-Pricing Model (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.45%	1.94%
Expected term (in years)	6 years 25 days	6 years 1 month 6 days
Expected volatility	72.26%	71.41%
Expected dividend yield	0.00%	0.00%

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of shares, Outstanding at beginning of period	3,505,119	907,315
Number of shares, Granted	1,083,274	2,761,034
Number of shares, Exercised	(416,157)
Number of shares, Forfeited	(40,113)	(163,230)
Number of shares, Outstanding at end of period	4,132,123	3,505,119	907,315
Number of shares, Options Exercisable	1,217,497	611,927
Number of shares, Options Unvested	2,914,626	2,893,192
Weighted average exercise price, Outstanding at beginning of period	$ 2.07	$ 1.66
Weighted average exercise price, Granted	18.57	2.21
Weighted average exercise price, Exercised	1.92
Weighted average exercise price, Forfeited	3.91	2.06
Weighted average exercise price, Outstanding at end of period	6.39	2.07	$ 1.66
Weighted average exercise price, Options exercisable	1.96	1.69
Weighted average exercise price, Options Unvested	$ 8.25	$ 2.15
Weighted average remaining contractual term (in years) , Outstanding	8 years 7 months 20 days	8 years 11 months 23 days	8 years 6 months 18 days
Weighted average remaining contractual term (in years), Options Exercisable	7 years 10 months 13 days	6 years 9 months
Weighted average remaining contractual term (in years), Options Unvested	8 years 11 months 15 days	9 years 5 months 12 days
Intrinsic value, Outstanding at end of period	$ 115,328
Intrinsic value, Options exercisable	39,374
Intrinsic value, Options unvested	$ 75,926

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Share-based Compensation Expense (Details) - Stock Options - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 2,537	$ 511
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	890	250
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 1,647	$ 261

Collaborations - Additional Inf

Collaborations - Additional Information (Details) ¥ in Millions	May 26, 2020USD ($)	Jan. 01, 2019USD ($)	Jan. 01, 2019JPY (¥)	Jun. 30, 2020USD ($)	May 31, 2020USD ($)	Dec. 31, 2020USD ($)	Jun. 23, 2020shares	Dec. 31, 2019USD ($)	Jan. 01, 2019JPY (¥)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from issuance of warrant						$ 15,000,000
Common Shares
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Shares issued upon exercise of warrants outstanding | shares							750,000
Bristol-Myers Squibb Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable upfront payment received						50,000,000
Affiliate of Bristol Myers Squibb
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from issuance of warrant	$ 15,000,000				$ 15,000,000
Affiliate of Bristol Myers Squibb | Common Shares
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Shares issued upon exercise of warrants outstanding | shares							750,000
Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable upfront payment received		$ 8,100,000				8,100,000		$ 8,100,000	¥ 900
Initial nonrefundable upfront fee payment received		1,000,000	¥ 110
Deferred revenue, additions		7,300,000	750
Collaboration and License Agreement | Bristol-Myers Squibb Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Non-refundable upfront payment received					$ 50,000,000
Initial nonrefundable upfront fee payment received				$ 50,000,000
Collaboration term expiration period					42 months
Deferred revenue recognized						100,000
Deferred revenue						49,900,000
Deferred revenue, current						2,100,000
Deferred revenue, noncurrent						$ 47,800,000
Collaboration and License Agreement | Bristol-Myers Squibb Company | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments entitled to be received					$ 301,000,000
Research, Development and Regulatory Milestones | Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Initial nonrefundable upfront fee payment received		7,100,000	¥ 790
Research, Development and Regulatory Milestones | Collaboration and License Agreement | Bristol-Myers Squibb Company | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments entitled to be received					176,000,000
Commercial Milestones | Collaboration and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments entitled to be received		$ 166,700,000							¥ 17,210
Commercial Milestones | Collaboration and License Agreement | Bristol-Myers Squibb Company | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments entitled to be received					$ 125,000,000

Collaboration - Schedule of Tra

Collaboration - Schedule of Transaction Price Performance Obligations (Details) - Bristol-Myers Squibb Company $ in Thousands	Dec. 31, 2020USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price	$ 50,000
Research Activities
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price	6,405
Options to License Druggable Targets
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price	31,148
Options to License Undruggable Targets
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price	$ 12,447

Income Taxes - Summary of Loss

Income Taxes - Summary of Loss Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Canada	$ (55,446)	$ (27,355)
Foreign	704	334
Loss before the provision for income taxes	$ (54,742)	$ (27,021)

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Loss before income taxes	$ (54,742)	$ (27,021)
Income tax at statutory rate	26.50%	26.50%
Computed income tax recovery	$ (14,507)	$ (7,160)
Federal investment tax credit	(2,347)	(985)
Accounting charges not deductible for tax purposes	346	277
Other	(306)	(16)
Change in valuation allowance	15,489	8,079
Tax (benefit) expense	$ (1,325)	$ 195

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Income tax losses	$ 19,198,000
Scientific research and experimental development expenditures	28,200,000
Investment tax credits	$ 4,304,000
Tax examination	2016 2017 2018 2019 2020
Unrecognized tax positions	$ 0	$ 0
Accrued interest or penalties	0	$ 0
U.S. Federal Research and Development
Income Taxes [Line Items]
Tax credit carryforward, amount	$ 800,000
Tax credit carry forward expiration year	2038
U.S. State Research and Development
Income Taxes [Line Items]
Tax credit carryforward, amount	$ 200,000
Tax credit carry forward expiration year	2038

Income Taxes - Summary of Losse

Income Taxes - Summary of Losses Expire (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Income Tax Disclosure [Abstract]
2039	$ 11,395
2038	7,053
2037	750
Total	$ 19,198

Income Taxes - Summary of Inves

Income Taxes - Summary of Investment Tax Credits Expire (Details) $ in Thousands	Dec. 31, 2020USD ($)
Income Tax Disclosure [Abstract]
2040	$ 1,687
2039	1,362
2038	776
2037	455
2036	24
Total	$ 4,304

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 5,087	$ 8,442
Net research and development expenditures	7,478	4,195
Share issuance costs	4,506	78
Net federal investment tax credits	3,181	1,877
U.S. research and development tax credits	961
Tax basis of property and equipment in excess of carrying values	(86)	(204)
Operating lease right-of-use assets	(1,240)	(279)
Operating lease liability	1,063	287
Accrued expense and other liabilities	345	161
Deferred revenue	15,372
Share-based compensation	103
Total deferred tax assets	36,770	14,557
Valuation allowance	(35,358)	(14,425)
Net deferred tax assets	$ 1,412	$ 132

Net Loss per Share - Summary of

Net Loss per Share - Summary of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss attributable to common shareholders—basic and diluted	$ (53,417)	$ (27,216)
Net loss attributable to common shareholders—basic and diluted	$ (53,417)	$ (27,216)
Denominator:
Weighted-average common shares outstanding—basic and diluted	20,045,602	1,528,374
Net loss per share attributable to common shareholders—basic and diluted	$ (2.66)	$ (17.81)

Net Loss per Share - Computatio

Net Loss per Share - Computation of Diluted Net Loss Per Share in Attributable to Common Shareholders Indicate to Anti Diluted Effect (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Options to Purchase Common Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	4,132,123	3,505,119
Series A Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		11,090,135
Series B Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		10,468,258

Government Assistance - Additio

Government Assistance - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Research And Development [Abstract]
Reduction of research and development expenditures	$ 909	$ 566

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Commitments to Settle Contractual Obligations (Details) $ in Thousands	Dec. 31, 2020USD ($)
Commitments And Contingencies Disclosure [Abstract]
2021	$ 1,525
2022	2,441
2023	2,325
2024	2,341
2025	25
Total	$ 8,657

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Details) - USD ($)	1 Months Ended			12 Months Ended
	Apr. 30, 2020	Mar. 31, 2020	Feb. 28, 2019	Dec. 31, 2020
Maximum | Research and Development Service Agreement
Commitments And Contingencies Disclosure [Line Items]
Potential milestone payments achieved				$ 1,750,000
Termination payments				$ 500,000
MDACC | Preclinical Studies and Clinical Trials
Commitments And Contingencies Disclosure [Line Items]
Contractual obligation		$ 10,000,000
Contractual obligation period		5 years
Contractual obligation paid	$ 2,000,000
Broad Institute, Inc. | Specialty Screening Services
Commitments And Contingencies Disclosure [Line Items]
Contractual obligation			$ 1,500,000
Contractual obligation period			3 years
Contractual obligation per year			$ 500,000

Currency Risk - Schedule of Fin

Currency Risk - Schedule of Financial Position Exposure (Details) - CAD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Foreign Currency Risk [Line Items]
Net financial position exposure	$ 881	$ 32,348
Cash
Foreign Currency Risk [Line Items]
Assets exposure	1,715	29,983
Restricted Cash
Foreign Currency Risk [Line Items]
Assets exposure	270	270
Research and Development Tax Credits Receivable
Foreign Currency Risk [Line Items]
Assets exposure	2,559	1,403
Other Receivables
Foreign Currency Risk [Line Items]
Assets exposure	5,228	2,566
Accounts Payable
Foreign Currency Risk [Line Items]
Liability exposure	(1,322)	(1,026)
Accrued Expenses and Other Current Liabilities
Foreign Currency Risk [Line Items]
Liability exposure	(2,722)	(283)
Lease Liabilities
Foreign Currency Risk [Line Items]
Liability exposure	$ (4,847)	$ (565)

Currency Risk - Additional Info

Currency Risk - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Foreign Currency Risk [Abstract]
Percentage of depreciation USD against Canadian dollar	10.00%
Increase in net loss currency risk	$ 0.1

Related Parties - Additional In

Related Parties - Additional Information (Details) - Affiliated Entity - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Due to related parties, current	$ 0	$ 0.2
Research Services and Rent Paid
Related Party Transaction [Line Items]
Expenses from transactions with related party	$ 0	$ 1.3

Geographic Information - Schedu

Geographic Information - Schedule of Property and Equipment, Net by Location (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Property and equipment, net	$ 3,948	$ 2,390
Canada
Segment Reporting Information [Line Items]
Property and equipment, net	3,845	2,279
United States
Segment Reporting Information [Line Items]
Property and equipment, net	$ 103	$ 111

Geographic Information - Sche_2

Geographic Information - Schedule of Right-of-Use Assets by Location (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating lease right-of-use assets	$ 4,674	$ 1,034
Canada
Segment Reporting Information [Line Items]
Operating lease right-of-use assets	4,483	409
United States
Segment Reporting Information [Line Items]
Operating lease right-of-use assets	$ 191	$ 625

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - $ / shares	1 Months Ended		12 Months Ended
	Mar. 31, 2021	Feb. 28, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Number of shares, Granted			1,083,274	2,761,034
Weighted average exercise price, Granted			$ 18.57	$ 2.21
2020 Equity Incentive Plan | Stock Options | Scenario Forecast
Subsequent Event [Line Items]
Number of shares, Granted	1,141,726
Weighted average exercise price, Granted	$ 36.49
2020 Equity Incentive Plan | Stock Options | Subsequent Event
Subsequent Event [Line Items]
Number of shares, Granted		1,141,726
Weighted average exercise price, Granted		$ 36.49