Xenon Pharmaceuticals (XENE) 10-K 29 Feb 24 2023 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 26, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Entity Registrant Name	XENON PHARMACEUTICALS INC.
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		75,432,482
Entity Public Float			$ 2,443.4
Amendment Flag	false
Trading Symbol	XENE
Entity Central Index Key	0001582313
Document Annual Report	true
Document Transition Report	false
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Shares, without par value
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Entity Tax Identification Number	98-0661854
Entity Address, Address Line One	200-3650 Gilmore Way
Entity Address, City or Town	Burnaby
Entity Address, State or Province	BC
City Area Code	604
Local Phone Number	484-3300
Entity File Number	001-36687
Entity Address, Postal Zip Code	V5G 4W8
Entity Incorporation, State or Country Code	Z4
Entity Address, Country	CA
ICFR Auditor Attestation Flag	true
Auditor Name	KPMG LLP
Auditor Firm ID	85
Auditor Location	Vancouver, BC, Canada
Documents Incorporated by Reference	Portions of the Registrant’s Definitive Proxy Statement relating to the 2024 Annual Meeting of Shareholders, which will be filed with the Securities and Exchange Commission subsequent to the date hereof, are incorporated by reference into Part III of this Report. Such Proxy Statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the Registrant’s fiscal year ended December 31, 2023 .

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 148,643	$ 57,242
Marketable securities (note 6)	489,439	534,845
Accounts receivable	874	986
Prepaid expenses and other current assets	6,006	7,225
Total current assets	644,962	600,298
Marketable securities, long-term (note 6)	292,792	128,682
Operating lease right-of-use asset, net (note 8)	9,193	10,406
Property, plant and equipment, net (note 7)	9,653	6,500
Deferred tax assets (note 13)	802	509
Prepaid expenses, long-term	7,396	7,751
Total assets	964,798	754,146
Current liabilities:
Accounts payable and accrued expenses (note 9)	25,974	22,214
Operating lease liability (note 8)	1,299	488
Total current liabilities	27,273	22,702
Operating lease liability, long-term (note 8)	9,604	9,947
Total liabilities	36,877	32,649
Shareholders’ equity:
Common shares, without par value; unlimited shares authorized; issued and outstanding: 75,370,977 (December 31, 2022 - 62,587,701) (note 10)	1,436,374	1,065,136
Additional paid-in capital	156,764	142,108
Accumulated deficit	(665,140)	(482,747)
Accumulated other comprehensive loss	(77)	(3,000)
Total shareholders' equity	927,921	721,497
Total liabilities and shareholders’ equity	964,798	754,146
Commitments and contingencies (note 12)

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common shares, without par value
Common shares, shares authorized	Unlimited	Unlimited
Common shares, Issued	75,370,977	62,587,701
Common shares, Outstanding	75,370,977	62,587,701

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue (note 11)		$ 9,434	$ 18,437
Operating expenses:
Research and development	$ 167,512	105,767	75,463
General and administrative	46,542	32,810	21,967
Total operating expenses	214,054	138,577	97,430
Loss from operations	(214,054)	(129,143)	(78,993)
Other income (expense):
Interest income	27,620	8,713	466
Unrealized fair value gain (loss) on trading securities	3,550	(2,934)	(719)
Foreign exchange gain (loss)	199	(1,891)	358
Other income (expense)	31,369	3,888	105
Loss before income taxes	(182,685)	(125,255)	(78,888)
Income tax recovery (expense) (note 13)	292	(118)	6
Net loss	(182,393)	(125,373)	(78,882)
Net loss attributable to preferred shareholders		(437)	(1,795)
Net loss attributable to common shareholders	(182,393)	(124,936)	(77,087)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities (note 6)	2,923	(2,010)
Comprehensive loss	$ (179,470)	$ (127,383)	$ (78,882)
Net loss per common share (note 4):
Basic	$ (2.73)	$ (2.06)	$ (1.77)
Diluted	$ (2.73)	$ (2.06)	$ (1.77)
Weighted-average common shares outstanding (note 4):
Basic	66,889,005	60,542,142	43,627,452
Diluted	66,889,005	60,542,142	43,627,452

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Convertible Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2020	$ 171,355	$ 7,732	$ 397,748	$ 45,357	$ (278,492)	$ (990)
Balance (in Shares) at Dec. 31, 2020		1,016,000	35,012,125
Net loss for the year	(78,882)				(78,882)
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e)	447,283		$ 381,567	65,716
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e) (in shares)			16,143,472
Stock-based compensation expense (note 10c)	10,017			10,017
Issued pursuant to exercise of stock options	$ 260		$ 3,855	(3,595)
Issued pursuant to exercise of stock options (in Shares)	690,284		479,155
Balance at Dec. 31, 2021	$ 550,033	$ 7,732	$ 783,170	117,495	(357,374)	(990)
Balance (in Shares) at Dec. 31, 2021		1,016,000	51,634,752
Net loss for the year	(125,373)				(125,373)
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e)	277,766		$ 268,379	9,387
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e) (in shares)			9,357,348
Conversion of preferred shares to common shares (note 10d)		$ (7,732)	$ 7,732
Conversion of preferred shares to common shares (note 10d) (in shares)		(1,016,000)	1,016,000
Stock-based compensation expense (note 10c)	20,376			20,376
Issued pursuant to exercise of stock options	$ 705		$ 5,855	(5,150)
Issued pursuant to exercise of stock options (in Shares)	780,725		579,601
Other comprehensive loss (note 6)	$ (2,010)					(2,010)
Balance at Dec. 31, 2022	721,497		$ 1,065,136	142,108	(482,747)	(3,000)
Balance (in Shares) at Dec. 31, 2022			62,587,701
Net loss for the year	(182,393)				(182,393)
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e)	353,487		$ 330,010	23,477
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e) (in shares)			10,701,842
Conversion of pre-funded warrants to common shares (note 10e)			$ 35,913	(35,913)
Conversion of pre-funded warrants to common shares (note 10e) (in shares)			1,700,000
Stock-based compensation expense (note 10c)	32,372			32,372
Issued pursuant to exercise of stock options	$ 35		$ 5,315	(5,280)
Issued pursuant to exercise of stock options (in Shares)	587,536		381,434
Other comprehensive loss (note 6)	$ 2,923					2,923
Balance at Dec. 31, 2023	$ 927,921		$ 1,436,374	$ 156,764	$ (665,140)	$ (77)
Balance (in Shares) at Dec. 31, 2023			75,370,977

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities:
Net loss	$ (182,393)	$ (125,373)	$ (78,882)
Items not involving cash:
Depreciation	3,541	1,624	906
Deferred income tax (recovery) expense	(292)	(44)	58
Stock-based compensation	32,372	20,376	10,017
Unrealized foreign exchange (gain) loss	(640)	2,729	327
Unrealized fair value (gain) loss on trading securities	(3,550)	2,934	719
Changes in operating assets and liabilities:
Accounts receivable	130	1,757	(459)
Prepaid expenses and other current assets	1,574	(10,495)	(1,517)
Accounts payable and accrued expenses	3,931	8,062	2,971
Deferred revenue			(3,642)
Net cash used in operating activities	(145,327)	(98,430)	(69,502)
Investing activities:
Purchases of property, plant and equipment	(5,617)	(2,894)	(2,050)
Purchase of marketable securities	(793,907)	(551,137)	(389,474)
Proceeds from marketable securities	682,354	258,028	144,754
Net cash used in investing activities	(117,170)	(296,003)	(246,770)
Financing activities:
Issuance of common shares and pre-funded warrants, net of issuance costs (note 10a and note 10e)	353,487	277,766	447,283
Issuance of common shares pursuant to exercise of stock options	35	705	260
Net cash provided by financing activities	353,522	278,471	447,543
Effect of exchange rate changes on cash and cash equivalents	376	(2,484)	(592)
Increase (decrease) in cash and cash equivalents	91,401	(118,446)	130,679
Cash and cash equivalents, beginning of year	57,242	175,688	45,009
Cash and cash equivalents, end of year	148,643	57,242	175,688
Supplemental disclosures:
Cash paid for operating lease	1,624	919	824
Cash received for lease incentives	1,489
Supplemental disclosures of non-cash transactions:
Fair value of stock options exercised on a cashless basis	5,250	4,491	3,349
Fair value of pre-funded warrants exercised	$ 35,913
Purchases of property, plant and equipment included in accounts payable and accrued expenses		391
Right-of-use asset obtained in exchange for new operating lease liability (note 8)		$ 3,019
Increase in operating lease liability and accounts receivable related to lease incentives claimed in the period (note 8)			493
Increase in operating lease right-of-use asset and operating lease liability related to lease amendments (note 8)			$ 5,248

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ (182,393)	$ (125,373)	$ (78,882)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Nature of the Business

Nature of the Business	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the business	1. Nature of the business: Xenon Pharmaceuticals Inc. (the “Company”), incorporated in 1996 under the predecessor to the Business Corporations Act (British Columbia) and continued federally in 2000 under the Canada Business Corporations Act, is a neuroscience-focused biopharmaceutical company committed to improving the lives of people living with neurological and psychiatric disorders. The Company has incurred significant operating losses since inception. As of December 31, 2023, the Company had an accumulated deficit of $ 665,140 and a net loss of $ 182,393 for the year ended December 31, 2023. Management expects to continue to incur significant expenses in excess of revenue and to incur operating losses for the foreseeable future. To date, the Company has financed its operations primarily through the sale of equity securities, funding received from collaboration and license agreements, and debt financings. Until such time as the Company can generate substantial product revenue, if ever, management expects to finance the Company’s cash needs through a combination of collaboration agreements, equity and debt financings. The continuation of research and development activities and the future commercialization of its products are dependent on the Company’s ability to successfully raise additional funds when needed. It is not possible to predict either the outcome of future research and development programs or the Company’s ability to continue to fund these programs in the future.

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	2. Basis of presentation: These consolidated financial statements are presented in U.S. dollars and have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”). The Company has one wholly-owned subsidiary as of December 31, 2023 , Xenon Pharmaceuticals USA Inc., which was incorporated in Delaware on December 2, 2016 . These consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany transactions and balances have been eliminated on consolidation.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Significant accounting policies	3. Significant accounting policies: (a) Use of estimates: The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant areas of estimates include, but are not limited to, revenue recognition including estimated timing of completion of performance obligations and the determination of stock-based compensation. These estimates and assumptions take into account historical and forward-looking factors that the Company believes are reasonable. Estimates and assumptions are reviewed quarterly. All revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected. (b) Cash and cash equivalents: Cash equivalents are highly liquid investments that are readily convertible into cash with terms to maturity of three months or less when acquired. Cash equivalents are recorded at cost plus accrued interest. (c) Marketable securities: Marketable securities are debt securities with original maturities exceeding three months and accrue interest based on a fixed interest rate for the term. Effective July 1, 2022, the Company classifies its marketable securities as either trading securities or available-for-sale securities. Marketable securities are carried at fair value. Fair value gains and losses for marketable securities classified as trading securities are recorded through the consolidated statement of operations. These securities are classified as current assets as the Company has the intent and ability to convert these securities into cash without penalty within the next 12 months. Unrealized fair value gains and losses for marketable securities classified as available-for-sale are recorded through other comprehensive income (loss) in shareholders' equity. When the fair value of an available-for-sale security falls below the amortized cost basis it is evaluated to determine if any of the decline in value is attributable to credit loss. Decreases in fair value attributable to credit loss are recorded directly to the consolidated statement of operations with a corresponding allowance for credit losses, limited to the amount that the fair value is less than the amortized cost basis. If the credit quality subsequently improves the allowance is reversed up to a maximum of the previously recorded credit losses. When the Company intends to sell an impaired available-for-sale security, or if it is more likely than not that the Company will be required to sell the security prior to recovering the amortized cost basis, the entire fair value adjustment will immediately be recognized in the consolidated statement of operations with no corresponding allowance for credit losses. Realized gains and losses and credit losses, if any, on available-for-sale securities are included in interest income, based on the specific identification method. Available-for-sale securities are also adjusted for amortization of premiums and accretion of discounts to maturity, with such amortization and accretion included within interest income. Available-for-sale securities with a remaining maturity date greater than one year are classified as non-current assets . (d) Intellectual property: The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred. (e) Property, plant and equipment: Property, plant and equipment are stated at cost less accumulated depreciation and/or accumulated impairment losses, if any. Repairs and maintenance costs are expensed in the period incurred. Property, plant and equipment are amortized over their estimated useful lives using the straight-line method based on the following rates: Asset Rate Research equipment 5 years Office furniture and equipment 5 years Computer equipment 3 years Leasehold improvements Over the lesser of lease term or (f) Impairment of long-lived assets: The Company monitors its long-lived assets for indicators of impairment. If such indicators are present, the Company assesses the recoverability of affected assets by determining whether the carrying value of such assets is less than the sum of the undiscounted future cash flows of the assets. If such assets are found not to be recoverable, the Company measures the amount of such impairment by comparing the carrying value of the assets to the fair value of the assets, with the fair value generally determined based on the present value of the expected future cash flows associated with the assets. No impairment of long-lived assets was noted during the years ended December 31, 2023, 2022 and 2021 . (g) Leases: Leases classified as operating leases are recorded as lease liabilities based on the present value of minimum lease payments over the lease term, discounted using the lessor’s rate implicit in the lease or the Company’s incremental borrowing rate, if the lessor’s implicit rate is not readily determinable. The lease term includes all periods covered by renewal and termination options where the Company is reasonably certain to exercise the renewal options or not to exercise the termination options. Corresponding right-of-use assets are recognized consisting of the lease liabilities, initial direct costs and any lease incentive payments. Lease liabilities are drawn down as lease payments are made and right-of-use assets are depreciated over the term of the lease. Operating lease expenses are recognized on a straight-line basis over the term of the lease, consisting of interest accrued on the lease liability and depreciation of the right-of-use asset, adjusted for changes in index-based variable lease payments in the period of change. Lease payments on short-term operating leases with lease terms twelve months or less are expensed on a straight-line basis over the lease term. The Company has elected to not separate non-lease elements embedded in its lease agreements. (h) Concentration of credit risk and of significant customers: Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents and marketable securities. The Company's investments are limited to investment-grade securities with strong credit ratings with the objective to preserve capital and maintain liquidity. Cash and cash equivalents were held at major financial institutions in Canada and the United States which may at times be in excess of federally insured limits. The Company does not believe that it is subject to credit risk beyond the standard credit risk associated with commercial banking relationships. Neurocrine Biosciences, Inc. ("Neurocrine Biosciences") accounted for 100 % of revenue recognized for the year ended December 31, 2022. Neurocrine Biosciences and Pacira BioSciences, Inc. (“Pacira BioSciences”) accounted for 84 % and 16 % of revenue recognized for the year ended December 31, 2021, respectively. (i) Financial instruments and fair value: The Company measures certain financial instruments and other items at fair value. To determine the fair value, the Company uses the fair value hierarchy for inputs used to measure fair value of financial assets and liabilities. This hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels: Level 1 (highest priority), Level 2, and Level 3 (lowest priority). • Level 1 - Unadjusted quoted prices in active markets for identical instruments. • Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Inputs are unobservable and reflect the Company’s assumptions as to what market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The carrying amount of accounts receivable, accounts payable and accrued expenses approximates fair value due to the nature and short-term of those instruments. The Company’s cash and cash equivalents and marketable securities are measured at fair value on a recurring basis and the level of fair value hierarchy utilized is described in note 5. (j) Revenue recognition: The Company recognizes the amount of revenue to which it expects to be entitled, for the transfer of promised goods or services to customers under a five-step model: (i) identify 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 a performance obligation is satisfied. Collaboration agreements may require the Company to deliver various rights and/or services, including intellectual property rights or licenses and research and development services. Under such collaboration agreements, the Company is generally eligible to receive non-refundable upfront payments, funding for research and development services, milestone payments, and royalties. In contracts where the Company has more than one performance obligation to provide its customer with goods or services, each performance obligation is evaluated to determine whether it is distinct based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the contract is then allocated between the distinct performance obligations based on their respective relative standalone selling prices. The estimated standalone selling price of each deliverable reflects the Company’s best estimate of what the selling price would be if the deliverable was regularly sold on a standalone basis and is determined by reference to market rates for the good or service when sold to others or by using an adjusted market assessment approach if selling price on a standalone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control is transferred to the customer for the related goods or services. Consideration in exchange for research and development services performed by the Company on behalf of the licensee is recognized upon performance of such activities at rates consistent with prevailing market rates. Consideration associated with at-risk substantive performance milestones, including sales-based milestones, is recognized as revenue using the most likely amount method when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Sales-based royalties received in connection with licenses of intellectual property are subject to a specific exception in the revenue standards, whereby the consideration is not included in the transaction price and recognized in revenue until the customer’s subsequent sales or usages occur. (k) Research and development costs: Research and development costs are expensed in the period incurred. Research and development expenses consist of costs incurred in performing research and development activities, including personnel-related expenses, consisting of salaries, benefits and stock-based compensation for employees engaged in scientific research and development, third-party expenses incurred in connection with the pre-clinical and clinical development of product candidates including under agreements with clinical research organizations, third-party expenses relating to formulation, process development and manufacture of drug substance and drug product for use in pre-clinical testing and clinical trials, third-party acquisition, license and collaboration fees, laboratory consumables and certain indirect costs incurred in support of overall research and development activities, including facilities, depreciation and information technology costs. The amount of expenses recognized in a period related to service agreements is based on the work performed using the accrual basis of accounting. Third-party service providers generally provide estimates of proportionate performance to allow the Company to determine an appropriate accrual. When determining the adequacy of an accrual, the Company analyzes progress based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. Payments made to third parties under these arrangements in advance of the receipt of the related services are recorded as prepaid expenses until the services are rendered. Prepaid expenses are recorded as current or non-current assets based on the expected timing of services. (l) Stock-based compensation: The Company grants stock options to employees, consultants, directors and officers pursuant to stock option plans described in note 10c. Employee stock-based compensation expense is measured at the grant date, based on the estimated fair value of the award, and is recognized as an expense, net of actual forfeitures, over the requisite service period with a corresponding increase in additional paid-in capital. Stock-based compensation expense is amortized on a straight-line basis over the requisite service period for the entire award, which is generally the vesting period of the award. Any consideration received on exercise of stock options is credited to share capital. (m) Foreign currency translation: The functional and reporting currency of the Company and its subsidiary is the U.S. dollar. Monetary assets and liabilities denominated in a currency other than the U.S. dollar are re-measured into U.S. dollars at the exchange rate prevailing as of the balance sheet date. Non-monetary assets and liabilities acquired in a currency other than U.S. dollars are translated at historical exchange rates prevailing at each transaction date. Revenue and expense transactions ar e translated at the approximate exchange rate prevailing on the date of transaction. Exchange gains and losses on translation are included in the consolidated statements of operations and comprehensive income (loss) as foreign exchange gain (loss). (n) Income taxes: Deferred income taxes are recognized for the future tax consequences attributable to differences between the carrying amounts of assets and liabilities and their respective tax bases and net operating loss and credit carryforwards. Deferred income tax assets and liabilities are measured at enacted rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations and comprehensive income (loss) in the period that includes the enactment date. A valuation allowance is provided when realization of deferred income tax assets does not meet the more-likely-than-not criterion for recognition. (o) Segment and geographic information: Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment. (p) Recent accounting pronouncements: From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that the Company adopts as of the specified effective date. The Company has evaluated recently issued accounting pronouncements and, based on preliminary assessment, does not believe any will have a material impact on the Company’s financial statements.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	4. Net income (loss) per common share: Basic net income (loss) per common share is calculated using the two-class method required for participating securities which includes the Series 1 Preferred Shares as a separate class. The convertible preferred shares entitle the holders to participate in dividends and in earnings and losses of the Company on an equivalent basis as common shares. Accordingly, undistributed earnings (losses) are allocated to common shares and participating preferred shares based on the weighted-average shares of each class outstanding during the period. In March 2022, the outstanding 1,016,000 Series 1 Preferred Shares were converted and exchanged for an equal number of common shares of the Company (note 10d). The weighted average number of common shares used in the basic and diluted net income (loss) per common share calculations includes the weighted-average pre-funded warrants outstanding during the period as they are exercisable at any time for nominal cash consideration. The treasury stock method is used to compute the dilutive effect of the Company’s stock options and warrants. Under this method, the incremental number of common shares used in computing diluted net income (loss) per common share is the difference between the number of common shares assumed issued and purchased using assumed proceeds. The if-converted method is used to compute the dilutive effect of the Company’s convertible preferred shares. Under the if-converted method, dividends on the preferred shares, if applicable, are added back to earnings attributable to common shareholders, and the preferred shares and paid-in kind dividends are assumed to have been converted at the share price applicable at the end of the period. The if-converted method is applied only if the effect is dilutive. For the years ended December 31, 2023, 2022 and 2021, diluted net loss per share attributable to common shareholders is the same as basic net loss per share attributable to common shareholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	5. Fair value of financial instruments: The level of the fair value hierarchy utilized to determine the fair va lue of cash and cash equivalents and marketable securities consisted of the following: December 31, 2023 December 31, 2022 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and cash equivalents Cash and money market fund $ 148,643 $ — $ — $ 148,643 $ 57,242 $ — $ — $ 57,242 Marketable securities Guaranteed investment certificates 7,684 — — 7,684 14,953 — — 14,953 U.S. treasuries 252,982 — — 252,982 322,851 — — 322,851 U.S. government securities — 97,912 — 97,912 — 32,479 — 32,479 Commercial paper — 119,108 — 119,108 — 150,560 — 150,560 Corporate debt securities — 304,545 — 304,545 — 142,684 — 142,684 Total $ 409,309 $ 521,565 $ — $ 930,874 $ 395,046 $ 325,723 $ — $ 720,769 The fair values of the Company’s U.S. government securities, commercial paper and corporate debt securities are based on prices obtained from independent pricing sources. Securities with validated quotes from pricing services are reflected within Level 2, as they are primarily based on observable pricing for similar assets or other market observable inputs. Typical inputs used by these pricing services include, but are not limited to, reported trades, benchmark yields, issuer spreads, bids, offers or estimates of cash flow, prepayment spreads and default rates. As of December 31, 2023 and December 31, 2022, the Company does not hold any securities classified as Level 3.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	6. Marketable securities: As of December 31, 2023 , the Company had $ 13,867 of trading securities and $ 768,364 of available-for-sale securities ( December 31, 2022 – $ 276,642 and $ 386,885 , respectively). Amortized cost, unrealized gain (losses) recognized in accumulated other comprehensive income (loss) and fair value of available-for-sale securities consisted of the following: December 31, 2023 December 31, 2022 Amortized Unrealized Gain (Loss) Fair Amortized Unrealized Fair Contractual maturity of 0 to 1 years: Guaranteed investment certificates $ 7,549 $ 135 $ 7,684 $ 14,953 $ — $ 14,953 U.S. treasuries 192,193 ( 249 ) 191,944 78,880 ( 837 ) 78,043 U.S. government securities 98,092 ( 180 ) 97,912 5,793 ( 20 ) 5,773 Commercial paper 119,041 67 119,108 150,560 — 150,560 Corporate debt securities 58,824 100 58,924 8,942 ( 68 ) 8,874 Contractual maturity of 1 to 3 years: U.S. treasuries 53,294 243 53,537 60,354 ( 958 ) 59,396 U.S. government securities — — — 26,741 ( 35 ) 26,706 Corporate debt securities 238,458 797 239,255 42,672 ( 92 ) 42,580 Total $ 767,451 $ 913 $ 768,364 $ 388,895 $ ( 2,010 ) $ 386,885 Allowance for credit losses or impairment on these marketable securities have not been recognized as these securities are high credit quality, investment grade securities that the Company does not intend to sell and will not be required to sell prior to their anticipated recovery, and the decline in fair value is primarily due to changes in interest rates.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	7. Property, plant and equipment: Property, plant and equipment consisted of the following: December 31, 2023 2022 Research equipment $ 9,111 $ 8,921 Office furniture and equipment 1,285 868 Computer equipment 1,489 1,213 Leasehold improvements 9,019 4,203 Less: accumulated depreciation and amortization ( 11,251 ) ( 8,705 ) Net book value $ 9,653 $ 6,500

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	8. Leases: The Company has an operating lease for research laboratories and office space in Burnaby, British Columbia which expires on June 30, 2032 , and two renewal options for 5 -years each which were not considered in the determination of the right-of-use asset and lease liability . The Company has an additional operating lease for office space in Needham, Massachusetts ("Needham Lease"), which commenced in October 2022. The Needham Lease is for a 62-month term and an option to terminate one year prior to the expiry date , which was not considered in the determination of the right-of-use asset and lease liability. The cost components of the operating leases were as follows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 Lease Cost Operating lease expense $ 1,645 $ 1,126 $ 591 Variable lease expense (1) 787 774 751 Lease Term and Discount Rate Weighted average remaining lease term (years) 7.33 8.07 10.50 Weighted average discount rate 3.87 % 3.97 % 3.42 % (1) Variable lease costs are payments that vary because of changes in facts or circumstances and include common area maintenance and property taxes related to the premises. Variable lease costs are excluded from the calculation of minimum lease payments. Future minimum lease payments as of December 31, 2023 were as follows: Year ending December 31: 2024 $ 1,698 2025 1,768 2026 1,837 2027 1,825 2028 1,126 2029 and thereafter 4,283 Total future minimum lease payments $ 12,537 Less: imputed interest ( 1,634 ) Present value of lease liabilities $ 10,903

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses: Accounts payable and accrued expenses consisted of the following: December 31, 2023 2022 Trade payables $ 8,598 $ 8,491 Employee compensation, benefits, and related accruals 7,425 5,823 Consulting and contracted research 8,824 7,148 Professional fees 780 411 Other 347 341 Total $ 25,974 $ 22,214

Share Capital

Share Capital	12 Months Ended
	Dec. 31, 2023
Stockholders' Equity Note [Abstract]
Share Capital	10. Share capital: (a) Financing: In August 2020, the Company entered into an “at-the-market” equity offering sales agreement, amended as of March 2022, with Jefferies LLC (“Jefferies”) and Stifel, Nicolaus & Company, Incorporated (“Stifel”) pursuant to which the Company may sell common shares from time to time. In January 2021, the Company sold an aggregate of 733,000 common shares for proceeds of $ 10,693 , net of commissions and transaction expenses pursuant to a prospectus supplement filed in August 2020 (“August 2020 ATM”). The Company may sell common shares having gross proceeds of up to $ 250,000 , from time to time, pursuant to a new prospectus supplement filed in March 2022 (“March 2022 ATM”), replacing the August 2020 ATM. As of December 31, 2023, the Company has sold an aggregate of 855,685 common shares for proceeds of $ 29,508 , net of commissions and transaction expenses under the March 2022 ATM. In March 2021, the Company completed an underwritten public offering of 5,135,135 common shares, including 810,810 common shares sold upon the full exercise of the underwriters’ over-allotment option, at a public offering price of $ 18.50 per common share and pre-funded warrants to purchase 1,081,081 common shares at $ 18.4999 per pre-funded warrant (note 10e) , with each pre-funded warrant having an exercise price of $ 0.0001 . The public offering was completed in March 2021, and the Company received proceeds of $ 107,922 , net of underwriting discounts, commissions and offering expenses. In September 2021, in connection with the License and Collaboration Agreement with Neurocrine Biosciences entered in December 2019 and amended in January 2021 (the “Neurocrine Collaboration Agreement”), the Company executed a Share Purchase Agreement (“SPA”) pursuant to which the Company issued 275,337 common shares for an aggregate purchase price of $ 5,500 , or $ 19.9755 per common share, which represents a premium of $ 770 when measured at fair value on the date of issuance. In addition, in January 2022, the Company executed a SPA pursuant to which the Company issued 258,986 common shares for an aggregate purchase price of $ 8,250 , or $ 31.855 per common share, which represents a premium of $ 374 when compared to the fair value of common shares on the date of issuance. The SPAs contain certain other customary terms and conditions, including mutual representations, warranties and covenants. For additional information regarding the Neurocrine Collaboration Agreement, refer to note 11a. In October 2021, the Company completed an underwritten public offering of 10,000,000 common shares, including 1,525,423 common shares sold upon the full exercise of the underwriters’ over-allotment option, at a public offering price of $ 29.50 per common share and pre-funded warrants to purchase 1,694,915 common shares at $ 29.4999 per pre-funded warrant (note 10e), with each pre-funded warrant having an exercise price of $ 0.0001 . The public offering was completed in October 2021, and the Company received proceeds of $ 323,938 , net of underwriting discounts, commissions and offering expenses. In June 2022, the Company completed an underwritten public offering of 9,098,362 common shares, including 1,229,508 shares sold upon the full exercise of the underwriters’ over-allotment option, at a public offering price of $ 30.50 per common share and pre-funded warrants to purchase 327,868 common shares at $ 30.4999 per pre-funded warrant (note 10e), with each pre-funded warrant having an exercise price of $ 0.0001 . The public offering was completed in June 2022, and the Company received proceeds of $ 269,890 , net of underwriting discounts, commissions and offering expenses. In November 2023, the Company completed an underwritten public offering of 9,846,157 common shares, including 1,384,615 shares sold upon the full exercise of the underwriters' over-allotment option, at a public offering price of $ 32.50 per common share and pre-funded warrants to purchase 769,230 common shares at $ 32.4999 per pre-funded warrant (note 10e), with each pre-funded warrant having an exercise price of $ 0.0001 . The public offering was completed in December 2023, and the Company received proceeds of $ 323,979 , net of underwriting discounts, commissions and offering expenses. (b) Authorized share capital: The Company’s authorized share capital consists of an unlimited number of common and preferred shares without par value. (c) Stock-based compensation: The Company has three equity incentive plans: (i) a pre-existing stock option plan (the “Amended and Restated Stock Option Plan”), (ii) the 2014 Equity Incentive Plan (the “2014 Plan”) which was amended and restated in June 2020 and June 2022, and (iii) the 2019 Inducement Equity Incentive Plan (the “2019 Inducement Plan”). The Amended and Restated Stock Option Plan provided for the grant of stock options for the purchase of common shares to directors, officers, employees and consultants prior to the Company’s initial public offering. The stock options granted under the Amended and Restated Stock Option Plan vest on a graduated basis over a four-year period or less and each option’s maximum term is ten years . The 2014 Plan replaced the Amended and Restated Stock Option Plan. No further options will be granted under the Company’s Amended and Restated Stock Option Plan. The Amended and Restated Stock Option Plan will continue to govern the stock options granted thereunder. In June 2014, the shareholders of the Company approved the 2014 Plan, which was amended and replaced in June 2020 and June 2022 by the Amended and Restated 2014 Equity Incentive Plan (the “Amended and Restated 2014 Plan”). In September 2019, the board of directors of the Company adopted the 2019 Inducement Plan and, subject to the adjustment provisions of the 2019 Inducement Plan, reserved 400,000 of the Company’s common shares for issuance pursuant to equity awards granted under the 2019 Inducement Plan. The 2019 Inducement Plan was adopted without shareholder approval in accordance with the applicable Nasdaq Listing Rules. The 2019 Inducement Plan provided for the grant of equity-based awards, including share options, share appreciation rights, restricted share awards, restricted share unit awards and performance share awards, and its terms are substantially similar to the Company’s Amended and Restated 2014 Plan, including with respect to treatment of equity awards in the event of a “merger” or “change of control” as defined under the 2019 Inducement Plan, but with such other terms and conditions intended to comply with the Nasdaq inducement award exception or to comply with the Nasdaq acquisition and merger exception. The 2019 Inducement Plan was terminated in June 2020. No further options will be granted under the 2019 Inducement Plan, and the 2019 Inducement Plan will continue to govern the options granted thereunder. The shareholders of the Company approved the Amended and Restated 2014 Plan amended in June 2020 and June 2022, amending certain provisions of the Company’s 2014 Plan. The Amended and Restated 2014 Plan continues to permit the grant of stock-based compensation awards to directors, officers, employees and consultants of the Company and the issuance of restricted shares, restricted share units, share appreciation rights and performance shares. Under the Amended and Restated 2014 Plan, options granted generally vest on a graduated basis over a four-year period or less. The exercise price of the options is determined by the board of directors but must at least be equal to the fair market value of the common shares on the date of grant. Options may be exercised over a maximum term of ten years . The annual share increase provision of the 2014 Plan was eliminated and the number of common shares available for issuance was increased by 9,300,000 over the existing share reserve under the 2014 Plan. The number of common shares that can be issued through restricted share awards, restricted share unit awards, or performance share awards was amended to be limited to 1,000,000 common shares, in the aggregate. Other amendments were made to terms of the 2014 Plan with respect to repricing, change of control and payment of dividends and other distributions. As of December 31, 2023, a total of 3,460,724 common shares remain available for issuance pursuant to the Amended and Restated 2014 Plan. The following table presents the summary of stock option activity for the period: Number of Weighted Aggregate Options Price ($) (1) Intrinsic Value Outstanding, December 31, 2020 4,758,997 9.10 30,464 Granted 1,775,450 19.82 Exercised (2) ( 690,284 ) 7.34 11,306 Forfeited, cancelled or expired ( 205,931 ) 13.01 Outstanding, December 31, 2021 5,638,232 12.55 105,405 Granted 2,315,645 30.90 Exercised (2) ( 780,725 ) 9.47 19,651 Forfeited, cancelled or expired ( 55,370 ) 24.50 Outstanding, December 31, 2022 7,117,782 18.75 147,214 Granted 2,542,473 35.29 Exercised (2) ( 587,536 ) 13.58 14,526 Forfeited, cancelled or expired ( 178,217 ) 31.49 Outstanding, December 31, 2023 8,894,502 23.56 200,122 Exercisable, December 31, 2023 4,789,178 16.23 142,900 (1) Canadian dollar denominated stock options have been translated into U.S. dollars at a foreign exchange rate of 0.76 (2022 – 0.74 and 2021 – 0.79 ) as of December 31, 2023. (2) During the year ended December 31, 2023, 4,320 (2022 – 68,930 and 2021 – 66,215 ) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 377,114 (2022 – 510,671 and 2021 – 412,940 ) common shares for the cashless exercise of 583,216 (2022 – 711,795 and 2021 – 624,069 ) stock options. At December 31, 2023 , stock options outstanding and exercisable had a weighted average remaining contractual life of 7.4 years and 6.2 years, respectively. A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2023 is as follows: Number of Weighted Average Non-vested, January 1, 2023 3,587,374 16.60 Granted 2,542,473 22.52 Vested ( 1,847,714 ) 15.82 Forfeited or cancelled ( 176,809 ) 18.62 Non-vested, December 31, 2023 4,105,324 20.53 The aggregate fair value of options vested during the year ended December 31, 2023 was $ 29,233 ( 2022 – $ 13,752 and 2021 – $ 8,271 ). The fair value of stock options at the date of grant is estimated using the Black-Scholes option-pricing model which requires multiple subjective inputs. The risk-free interest rate of the options is based on the U.S. Treasury yield curve in effect at the date of grant for a term similar to the expected term of the option. The expected volatility is based on the historical volatility of the Company’s common shares calculated based on a period of time commensurate with the expected term assumption. Expected life assumptions are based on the Company’s historical data. The dividend yield is based on the fact that the Company has never paid cash dividends and has no present intention to pay cash dividends. Forfeitures are recognized as they occur. The weighted-average option pricing assumptions are as follows: Year Ended December 31, 2023 2022 2021 Average risk-free interest rate 3.93 % 2.39 % 1.16 % Expected volatility 69 % 70 % 68 % Average expected term (in years) 5.94 6.16 6.66 Expected dividend yield 0.00 % 0.00 % 0.00 % Weighted average fair value of options granted $ 22.52 $ 19.78 $ 12.54 Stock-based compensation expense is classified in the consolidated statements of operations and comprehensive income (loss) as follows: Year Ended December 31, 2023 2022 2021 Research and development expenses $ 13,067 $ 7,766 $ 3,734 General and administrative expenses 19,305 12,610 6,283 $ 32,372 $ 20,376 $ 10,017 As of December 31, 2023 , the unrecognized stock-based compensation expense related to the non-vested stock options was $ 70,691 which is expected to be recognized over a weighted-average period of 2.61 years. (d) Exchange agreement with certain funds affiliated with BVF Partners L.P. (collectively, “BVF”): In March 2018, the Company and BVF entered into an exchange agreement pursuant to which the Company issued to BVF 2,868,000 Series 1 Preferred Shares in exchange for 2,868,000 common shares which were subsequently cancelled by the Company. The Series 1 Preferred Shares were convertible into common shares on a one-for-one basis, subject to certain restrictions. The Series 1 Preferred Shares ranked equally to the common shares in the event of liquidation, dissolution or winding up or other distribution of the assets of the Company among its shareholders and the holders of the Series 1 Preferred Shares were entitled to vote together with the common shares on an as-converted basis and as a single class, subject to certain restrictions. The Series 1 Preferred Shares were recorded wholly as equity under ASC 480, with no bifurcation of conversion feature from the host contract, given that the Series 1 Preferred Shares cannot be cash settled and have no redemption features. During the year ended December 31, 2018, BVF converted 1,852,000 Series 1 Preferred Shares in exchange for an equal number of common shares. In March 2022, the remaining outstanding 1,016,000 Series 1 Preferred Shares were exchanged for an equal number of common shares. (e) Pre-funded warrants: The following table summarizes the pre-funded warrants activity for the years ended December 31, 2023, 2022, and 2021: Date of issuance March 2021 October 2021 June 2022 December 2023 Total Outstanding, December 31, 2020 — — — — — Issued 1,081,081 1,694,915 — — 2,775,996 Exercised — — — — — Outstanding, December 31, 2021 1,081,081 1,694,915 — — 2,775,996 Issued — — 327,868 — 327,868 Exercised — — — — — Outstanding, December 31, 2022 1,081,081 1,694,915 327,868 — 3,103,864 Issued — — — 769,230 769,230 Exercised ( 1,081,081 ) ( 618,932 ) — — ( 1,700,013 ) Outstanding, December 31, 2023 — 1,075,983 327,868 769,230 2,173,081 In connection with underwritten public offerings completed in March 2021, October 2021, June 2022, and December 2023, the Company issued pre-funded warrants to purchase the equivalent number of common shares at $ 18.4999 , $ 29.4999 , $ 30.4999 and $ 32.4999 per pre-funded warrant, respectively, with each pre-funded warrant having an exercise price of $ 0.0001 . The pre-funded warrants are exercisable at the holder’s discretion from the date of issuance until the date the pre-funded warrant is exercised in full. The Company may not affect the exercise of any pre-funded warrant, and a holder will not be entitled to exercise any portion of any pre-funded warrant that, upon giving effect to such exercise, would cause: (i) the aggregate number of common shares beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the total number of common shares outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Company’s securities beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the combined voting power of all of the Company’s securities immediately outstanding after giving effect to the exercise, which percentage may be changed at the holder’s election to a higher or lower percentage not in excess of 19.99% upon at least 61 days’ notice to the Company. Since the pre-funded warrants meet the condition for equity classification, proceeds from issuances of the pre-funded warrants of $ 23,477 ( 2022 – $ 9,387 and 2021 - 65,716 ), net of underwriting discounts, commissions and offering expenses, are recorded in additional paid-in capital. Upon exercise of the pre-funded warrants, the historical costs recorded in additional paid-in capital along with the exercise price collected from the holder are recorded in common shares. During the year ended December 31, 2023, the Company issued 1,700,000 common shares upon the exercise of 1,700,013 pre-funded warrants pursuant to a net exercise mechanism under the warrants. Pre-funded warrants to purchase 2,173,081 common shares ( 2022 – 3,103,864 and 2021 - 2,775,996 ) common shares are not included in the number of issued and outstanding common shares as of December 31, 2023. (f) Warrant: In August 2018, a warrant to purchase 40,000 ( 2022 - 40,000 ) common shares at a price per common share of $ 9.79 was issued. The warrant is immediately exercisable, contains a cashless exercise provision and expires in August 2028.

Collaboration Agreements

Collaboration Agreements	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration Agreements	11. Collaboration agreements: The Company has assessed each collaboration agreement in accordance with ASC 606 under the five-step model as described in note 3j, including recognition of non-refundable upfront payments. The Company generally recognizes revenue from non-refundable upfront payments over the estimated term of the performance obligation or period in which the underlying benefit is transferred to the customer. If non-refundable license fees have value to the customer on a standalone basis, separate from the undelivered performance obligations, they are recognized upon delivery. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Research and development milestones in the Company’s collaboration agreements may include the following types of events: • completion of pre-clinical research and development work leading to selection of product candidates; • initiation of Phase 1, Phase 2 or Phase 3 clinical trials; and • achievement of certain other scientific, clinical data or development events. Regulatory milestone payments may include the following types of events: • filing of regulatory applications for marketing approval in the U.S., Europe or Asia, including investigational new drug applications (“IND”) and new drug applications; and • marketing approval in a major market, such as the U.S., Europe or Asia. Commercialization milestone payments may include payments triggered by annual product sales that achieve pre-specified thresholds. The Company evaluates each arrangement that includes research and development and sales-based milestone payments to determine whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. Milestone payments that are not within the control of the Company are not considered probable of being achieved. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. The transaction price is then allocated to each performance obligation on a relative standalone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such milestones, and if necessary, adjusts its estimate of the overall transaction price. Revenue was as follows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 Neurocrine Biosciences: Recognition of the transaction price $ — $ 372 $ 3,715 Research and development services — 1,938 6,452 Milestone payments — 7,124 5,270 Pacira BioSciences: Milestone payments — — 3,000 Total revenue $ — $ 9,434 $ 18,437 (a) Neurocrine Biosciences license and collaboration agreement: In December 2019, the Company entered into the Neurocrine Collaboration Agreement with Neurocrine Biosciences. Pursuant to this agreement, the Company granted an exclusive license to XEN901, now known as NBI-921352, and an exclusive license to certain pre-clinical compounds for development (the “DTCs”). The agreement also includes a two-year research collaboration to discover, identify and develop additional novel Nav1.6 and Nav1.2/1.6 inhibitors (“Research Compounds”). The Company and Neurocrine Biosciences collaborated on the conduct of two collaboration programs: (a) a joint research collaboration to discover, identify and preclinically develop Research Compounds (the “Research Program”), which was completed in June 2022, and (b) a collaborative development program for NBI-921352 and two DTCs selected by the joint steering committee (the “Initial Development Program”). At execution of the agreement, Neurocrine Biosciences paid the Company an upfront fee of $ 50,000 , which included a $ 30,000 payment in cash and a $ 20,000 equity investment in the Company. The Company is eligible to receive pre-commercial and commercial milestone payments with respect to the licensed products totaling up to an additional $ 1,667,500 , comprised of up to $ 1,067,500 in additional development and regulatory milestone payments related to NBI-921352 and other licensed Nav1.6 or Nav1.2/1.6 inhibitor products, and up to $ 600,000 in additional sales-based milestone payments for multiple products. In addition, the Company is eligible to receive royalties on net sales in and outside the U.S., ranging from (a) for NBI-921352, a low double-digit percentage to a mid-teen percentage and a high-single digit percentage to low double-digit percentage, respectively; (b) for DTCs, a high-single digit percentage to a low double-digit percentage and a mid-single digit percentage to a high-single digit percentage, respectively; and (c) for Research Compounds, a mid-single digit percentage to a high-single digit percentage and a tiered mid-single digit percentage, respectively. Royalty rates are subject to customary reductions. The Company has an option to co-fund 50 % of the development costs of NBI-921352 or another product candidate in the U.S., exercisable upon achievement of certain milestones, in exchange for increased U.S. royalties. The Company has not exercised this option as of December 31, 2023. The agreement includes the following performance obligations: (i) an exclusive license to NBI-921352 with associated technology and know-how transfer, (ii) an exclusive license to the DTCs with associated know-how transfer, (iii) a license to Research Compounds and research services under the Research Program, (iv) development services under the Initial Development Program for NBI-921352, and (v) development services under the Initial Development Program for the DTCs. The license to the Research Compounds and the research services under the Research Program were considered a single performance obligation as Neurocrine Biosciences cannot benefit from such a license on its own or from other resources commonly available in the industry, without the corresponding research services due to the unique and specialized expertise of the Company that is not readily available in the marketplace. Given the early development phase of the Research Compounds, the performance obligation and related revenue was linked entirely to the performance of research services. At execution of the agreement, the transaction price consisted of the $ 30,000 upfront consideration received in cash and a premium of $ 3,333 on the $ 20,000 equity investment in the Company measured at fair value on the date of issuance. Under the arrangement, the Company was entitled to funding for certain full-time equivalent and external costs incurred by the Company under performance obligations (iii) and (iv). The arrangement consideration related to the services under performance obligations (iii) and (iv) to be performed on behalf of Neurocrine Biosciences were excluded from the initial transaction price allocation because the consideration and performance were contingent upon Neurocrine Biosciences requesting performance of the services and these services were priced at estimated fair value. The total transaction price of $ 33,333 was allocated to performance obligation (v) based on its estimated standalone selling price determined based on internal development plans and budget, with the balance allocated to performance obligations (i) and (ii) by the residual approach. The residual approach was used as standalone selling prices, including market data, for equivalent performance obligations were not available. The allocation of the transaction price requires significant management judgment. The Company allocated the transaction price as follows: $ 28,807 to performance obligations (i) and (ii) which were delivered and transferred concurrently and completed as of December 2020, and $ 5,025 , which includes $ 499 of variable consideration, to performance obligation (v), which was completed as of March 2022. The Company measured proportional performance over time using an input method based on cost incurred relative to the total estimated costs for each of the identified obligations at each reporting period. Any changes to estimates were recognized in the period in which they changed as a cumulative catch up. In September 2021, based on the regulatory approval of a clinical trial application in Europe for NBI-921352 for focal-onset seizures in adults, the Company received an aggregate milestone payment of $ 10,000 in the form of $ 4,500 in cash and a $ 5,500 equity investment in the Company (note 10a). The equity investment was measured at fair value of $ 4,730 on the date of issuance and the resulting premium of $ 770 , with the cash payment of $ 4,500 , was recognized as revenue in the period as the Company did no t have any remaining performance obligations in relation to this milestone on the date it was achieved. In January 2022, based on the receipt of the U.S. Food and Drug Administration’s (“FDA”) full IND acceptance for NBI-921352, the Company received an aggregate milestone payment of $ 15,000 in the form of $ 6,750 in cash and a $ 8,250 equity investment in the Company (note 10a). The equity investment was measured at fair value of $ 7,876 on the date of issuance and the resulting premium of $ 374 , with the cash payment of $ 6,750 , was recognized as revenue in the period as the Company did no t have any remaining performance obligations in relation to this milestone on the date it was achieved. During the years ended December 31, 2022 and 2021, the Company recognized revenue of $ 2,310 and $ 10,167 , respectively, which comprised of $ 1,938 and $ 6,452 , respectively, for the research and development services under (iii) the Research Program and (iv) the Initial Development Program for NBI-921352 and $ 372 and $ 3,715 , respectively, for (v) development services under the Initial Development Program for the DTCs. (b) Asset Purchase Agreement with Flexion Therapeutics, Inc., subsequently acquired by Pacira BioSciences: In September 2019, the Company entered into an agreement with Flexion Therapeutics Inc. (“Flexion”), which was acquired by Pacira BioSciences in November 2021, pursuant to which Flexion acquired all rights with respect to XEN402, and a related compound (collectively “XEN402”), including certain regulatory documentation, intellectual property rights, reports, data and all quantities of XEN402, known as PCRX-301, owned or controlled by the Company. During the year ended December 31, 2021, the FDA cleared the first investigational new drug application for PCRX-301 and a Phase 1b clinical trial was initiated, resulting in milestone payments of $ 1,000 and $ 2,000 paid to the Company, respectively. In November 2022, Pacira BioSciences made the strategic decision to no longer pursue the clinical development of PCRX-301.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and contingencies: (a) Asset purchase agreement with 1st Order Pharmaceuticals, Inc. (“1st Order”): In April 2017, the Company acquired XEN1101 (previously known as 1OP2198) from 1st Order pursuant to an asset purchase agreement. In August 2020, the Company and 1st Order amended the asset purchase agreement to amend certain definitions in the agreement and to modify the payment schedule for certain milestones. Through December 31, 2023, the Company has paid $ 2,000 based on progress against these milestones. Future potential payments to 1st Order related to the XEN1101 program include up to $ 6,000 in regulatory milestones. There are no royalty obligations to 1st Order. (b) Guarantees and indemnifications: The Company has entered into license and research agreements with third parties that include indemnification provisions that are customary in the industry. These indemnification provisions generally require the Company to compensate the other party for certain damages and costs incurred as a result of third-party claims or damages arising from these transactions. The maximum amount of potential future indemnification is unlimited; however, the Company currently holds commercial and product liability insurance. This insurance limits the Company’s exposure and may enable it to recover a portion of any future amounts paid. Historically, the Company has not made any indemnification payments under such agreements and the Company believes that the fair value of these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations for any period presented.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	13. Income taxes: Income tax recovery varies from the amounts that would be computed by applying the expected Canadian federal and provincial statutory income tax rate of 27 % ( 2022 and 2021 – 27 %) to loss before income taxes as shown in the following table: Year Ended December 31, 2023 2022 2021 Computed recoveries at Canadian federal and $ ( 49,325 ) $ ( 33,819 ) $ ( 21,300 ) Change in valuation allowance 43,829 30,732 21,354 Tax credits earned ( 2,868 ) ( 3,086 ) ( 2,279 ) Tax attributes expired/utilized 1,442 1,564 692 Non-deductible expenditures 6,482 4,463 2,033 Other 148 264 ( 506 ) Income tax expense (recovery) $ ( 292 ) $ 118 $ ( 6 ) Income tax expense (recovery) for the years ended December 31, 2023, 2022 and 2021 arose from the operations of Xenon Pharmaceuticals USA Inc., the Company’s wholly-owned subsidiary in the United States. Deferred income tax assets and liabilities result from the temporary differences between the amount of assets and liabilities recognized for financial statement and income tax purposes. The significant components of the Company’s net deferred income tax assets are as follows: December 31, 2023 2022 2021 Scientific research and experimental development pool $ 38,590 $ 34,891 $ 32,505 Tax credits 30,695 28,835 27,365 Non-capital losses 119,765 80,547 53,453 Depreciable assets 10,311 8,912 7,667 Deferred financing fees 10,831 8,928 7,252 Stock based compensation 3,832 1,492 585 Other 1,220 1,569 732 Less - valuation allowance ( 214,442 ) ( 164,665 ) ( 129,094 ) Net deferred income tax assets $ 802 $ 509 $ 465 The realization of deferred income tax assets is dependent upon the generation of sufficient taxable income during future periods in which the temporary differences are expected to reverse. The valuation allowance is reviewed on a quarterly basis and if the assessment of the “more likely than not” criteria changes, the valuation allowance is adjusted accordingly. A full valuation allowance continues to be applied against deferred income tax assets in Canada as the Company has assessed that the realization of such assets does not meet the “more likely than not” criteria. Deferred income tax assets recorded on the consolidated balance sheets as of December 31, 2023 and 2022, result from the temporary differences between the amounts of assets and liabilities recognized for financial statement and income tax purposes, net of valuation allowance, related to the operations of Xenon Pharmaceuticals USA Inc. At December 31, 2023 , the Company has unclaimed tax deductions for scientific research and experimental development expenditures of $ 142,925 ( 2022 – $ 129,226 ) with no expiry. At December 31, 2023 , the Company has $ 29,074 ( 2022 – $ 27,323 ) of investment tax credits available to offset federal taxes payable and $ 8,099 ( 2022 – $ 8,418 ) of provincial tax credits available to offset provincial taxes payable in the future. At December 31, 2023 , the Company has non-capital losses, net of uncertain tax positions, carried forward for tax purposes, which are available to reduce taxable income of future years of approximately $ 422,822 ( 2022 – $ 295,828 ). The investment tax credits and loss carry forwards expire over various years to 2043 . At December 31, 2023 , the total amount of the Company’s unrecognized tax benefits of uncertain tax positions were $ 10,850 ( 2022 – $ 10,850 ). If recognized in future periods, the unrecognized tax benefits would not affect the Company’s effective tax rate. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits within the income tax provision. Interest and penalties have not been accrued at December 31, 2023 and 2022 as none would be owing on the unrecognized tax benefits due to the availability of non-capital losses to shelter any potential taxable income arising thereon. The Company does not currently expect any significant increases or decreases to these unrecognized tax benefits within 12 months of the reporting date. The Company files income tax returns in Canada and the United States, the jurisdictions in which the Company believes that it is subject to tax. In jurisdictions in which the Company does not believe it is subject to tax and therefore does not file income tax returns, the Company can provide no certainty that tax authorities in those jurisdictions will not subject one or more tax years (since the inception of the Company) to examination. Further, while the statute of limitations in each jurisdiction where an income tax return has been filed generally limits the examination period, as a result of loss carry-forwards, the limitation period for examination generally does not expire until several years after the loss carry-forwards are utilized. Other than routine audits by tax authorities for tax credits and tax refunds that the Company claims, the Company is not aware of any other material income tax examination currently in progress by any taxing jurisdiction. Tax years ranging from 2003 to 2022 remain subject to examinations in Canada and the United States.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Use of estimates	(a) Use of estimates: The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant areas of estimates include, but are not limited to, revenue recognition including estimated timing of completion of performance obligations and the determination of stock-based compensation. These estimates and assumptions take into account historical and forward-looking factors that the Company believes are reasonable. Estimates and assumptions are reviewed quarterly. All revisions to accounting estimates are recognized in the period in which the estimates are revised and in any future periods affected.
Cash and cash equivalents	(b) Cash and cash equivalents: Cash equivalents are highly liquid investments that are readily convertible into cash with terms to maturity of three months or less when acquired. Cash equivalents are recorded at cost plus accrued interest.
Marketable Securities	(c) Marketable securities: Marketable securities are debt securities with original maturities exceeding three months and accrue interest based on a fixed interest rate for the term. Effective July 1, 2022, the Company classifies its marketable securities as either trading securities or available-for-sale securities. Marketable securities are carried at fair value. Fair value gains and losses for marketable securities classified as trading securities are recorded through the consolidated statement of operations. These securities are classified as current assets as the Company has the intent and ability to convert these securities into cash without penalty within the next 12 months. Unrealized fair value gains and losses for marketable securities classified as available-for-sale are recorded through other comprehensive income (loss) in shareholders' equity. When the fair value of an available-for-sale security falls below the amortized cost basis it is evaluated to determine if any of the decline in value is attributable to credit loss. Decreases in fair value attributable to credit loss are recorded directly to the consolidated statement of operations with a corresponding allowance for credit losses, limited to the amount that the fair value is less than the amortized cost basis. If the credit quality subsequently improves the allowance is reversed up to a maximum of the previously recorded credit losses. When the Company intends to sell an impaired available-for-sale security, or if it is more likely than not that the Company will be required to sell the security prior to recovering the amortized cost basis, the entire fair value adjustment will immediately be recognized in the consolidated statement of operations with no corresponding allowance for credit losses. Realized gains and losses and credit losses, if any, on available-for-sale securities are included in interest income, based on the specific identification method. Available-for-sale securities are also adjusted for amortization of premiums and accretion of discounts to maturity, with such amortization and accretion included within interest income. Available-for-sale securities with a remaining maturity date greater than one year are classified as non-current assets .
Intellectual property	(d) Intellectual property: The costs incurred in establishing and maintaining patents for intellectual property developed internally are expensed in the period incurred.
Property, plant and equipment	(e) Property, plant and equipment: Property, plant and equipment are stated at cost less accumulated depreciation and/or accumulated impairment losses, if any. Repairs and maintenance costs are expensed in the period incurred. Property, plant and equipment are amortized over their estimated useful lives using the straight-line method based on the following rates: Asset Rate Research equipment 5 years Office furniture and equipment 5 years Computer equipment 3 years Leasehold improvements Over the lesser of lease term or
Impairment of long-lived assets	(f) Impairment of long-lived assets: The Company monitors its long-lived assets for indicators of impairment. If such indicators are present, the Company assesses the recoverability of affected assets by determining whether the carrying value of such assets is less than the sum of the undiscounted future cash flows of the assets. If such assets are found not to be recoverable, the Company measures the amount of such impairment by comparing the carrying value of the assets to the fair value of the assets, with the fair value generally determined based on the present value of the expected future cash flows associated with the assets. No impairment of long-lived assets was noted during the years ended December 31, 2023, 2022 and 2021 .
Leases	(g) Leases: Leases classified as operating leases are recorded as lease liabilities based on the present value of minimum lease payments over the lease term, discounted using the lessor’s rate implicit in the lease or the Company’s incremental borrowing rate, if the lessor’s implicit rate is not readily determinable. The lease term includes all periods covered by renewal and termination options where the Company is reasonably certain to exercise the renewal options or not to exercise the termination options. Corresponding right-of-use assets are recognized consisting of the lease liabilities, initial direct costs and any lease incentive payments. Lease liabilities are drawn down as lease payments are made and right-of-use assets are depreciated over the term of the lease. Operating lease expenses are recognized on a straight-line basis over the term of the lease, consisting of interest accrued on the lease liability and depreciation of the right-of-use asset, adjusted for changes in index-based variable lease payments in the period of change. Lease payments on short-term operating leases with lease terms twelve months or less are expensed on a straight-line basis over the lease term. The Company has elected to not separate non-lease elements embedded in its lease agreements.
Concentration of credit risk and of significant customers	(h) Concentration of credit risk and of significant customers: Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents and marketable securities. The Company's investments are limited to investment-grade securities with strong credit ratings with the objective to preserve capital and maintain liquidity. Cash and cash equivalents were held at major financial institutions in Canada and the United States which may at times be in excess of federally insured limits. The Company does not believe that it is subject to credit risk beyond the standard credit risk associated with commercial banking relationships. Neurocrine Biosciences, Inc. ("Neurocrine Biosciences") accounted for 100 % of revenue recognized for the year ended December 31, 2022. Neurocrine Biosciences and Pacira BioSciences, Inc. (“Pacira BioSciences”) accounted for 84 % and 16 % of revenue recognized for the year ended December 31, 2021, respectively.
Financial instruments and fair value	(i) Financial instruments and fair value: The Company measures certain financial instruments and other items at fair value. To determine the fair value, the Company uses the fair value hierarchy for inputs used to measure fair value of financial assets and liabilities. This hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels: Level 1 (highest priority), Level 2, and Level 3 (lowest priority). • Level 1 - Unadjusted quoted prices in active markets for identical instruments. • Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 - Inputs are unobservable and reflect the Company’s assumptions as to what market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The carrying amount of accounts receivable, accounts payable and accrued expenses approximates fair value due to the nature and short-term of those instruments. The Company’s cash and cash equivalents and marketable securities are measured at fair value on a recurring basis and the level of fair value hierarchy utilized is described in note 5.
Revenue recognition	(j) Revenue recognition: The Company recognizes the amount of revenue to which it expects to be entitled, for the transfer of promised goods or services to customers under a five-step model: (i) identify 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 a performance obligation is satisfied. Collaboration agreements may require the Company to deliver various rights and/or services, including intellectual property rights or licenses and research and development services. Under such collaboration agreements, the Company is generally eligible to receive non-refundable upfront payments, funding for research and development services, milestone payments, and royalties. In contracts where the Company has more than one performance obligation to provide its customer with goods or services, each performance obligation is evaluated to determine whether it is distinct based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the contract is then allocated between the distinct performance obligations based on their respective relative standalone selling prices. The estimated standalone selling price of each deliverable reflects the Company’s best estimate of what the selling price would be if the deliverable was regularly sold on a standalone basis and is determined by reference to market rates for the good or service when sold to others or by using an adjusted market assessment approach if selling price on a standalone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control is transferred to the customer for the related goods or services. Consideration in exchange for research and development services performed by the Company on behalf of the licensee is recognized upon performance of such activities at rates consistent with prevailing market rates. Consideration associated with at-risk substantive performance milestones, including sales-based milestones, is recognized as revenue using the most likely amount method when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Sales-based royalties received in connection with licenses of intellectual property are subject to a specific exception in the revenue standards, whereby the consideration is not included in the transaction price and recognized in revenue until the customer’s subsequent sales or usages occur.
Research and development costs	(k) Research and development costs: Research and development costs are expensed in the period incurred. Research and development expenses consist of costs incurred in performing research and development activities, including personnel-related expenses, consisting of salaries, benefits and stock-based compensation for employees engaged in scientific research and development, third-party expenses incurred in connection with the pre-clinical and clinical development of product candidates including under agreements with clinical research organizations, third-party expenses relating to formulation, process development and manufacture of drug substance and drug product for use in pre-clinical testing and clinical trials, third-party acquisition, license and collaboration fees, laboratory consumables and certain indirect costs incurred in support of overall research and development activities, including facilities, depreciation and information technology costs. The amount of expenses recognized in a period related to service agreements is based on the work performed using the accrual basis of accounting. Third-party service providers generally provide estimates of proportionate performance to allow the Company to determine an appropriate accrual. When determining the adequacy of an accrual, the Company analyzes progress based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. Payments made to third parties under these arrangements in advance of the receipt of the related services are recorded as prepaid expenses until the services are rendered.
Stock-based compensation	(l) Stock-based compensation: The Company grants stock options to employees, consultants, directors and officers pursuant to stock option plans described in note 10c. Employee stock-based compensation expense is measured at the grant date, based on the estimated fair value of the award, and is recognized as an expense, net of actual forfeitures, over the requisite service period with a corresponding increase in additional paid-in capital. Stock-based compensation expense is amortized on a straight-line basis over the requisite service period for the entire award, which is generally the vesting period of the award. Any consideration received on exercise of stock options is credited to share capital.
Foreign currency translation	(m) Foreign currency translation: The functional and reporting currency of the Company and its subsidiary is the U.S. dollar. Monetary assets and liabilities denominated in a currency other than the U.S. dollar are re-measured into U.S. dollars at the exchange rate prevailing as of the balance sheet date. Non-monetary assets and liabilities acquired in a currency other than U.S. dollars are translated at historical exchange rates prevailing at each transaction date. Revenue and expense transactions ar e translated at the approximate exchange rate prevailing on the date of transaction. Exchange gains and losses on translation are included in the consolidated statements of operations and comprehensive income (loss) as foreign exchange gain (loss).
Income taxes	(n) Income taxes: Deferred income taxes are recognized for the future tax consequences attributable to differences between the carrying amounts of assets and liabilities and their respective tax bases and net operating loss and credit carryforwards. Deferred income tax assets and liabilities are measured at enacted rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in the consolidated statement of operations and comprehensive income (loss) in the period that includes the enactment date. A valuation allowance is provided when realization of deferred income tax assets does not meet the more-likely-than-not criterion for recognition.
Segment and geographic information	(o) Segment and geographic information: Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment.
Recent accounting pronouncements	(p) Recent accounting pronouncements: From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that the Company adopts as of the specified effective date. The Company has evaluated recently issued accounting pronouncements and, based on preliminary assessment, does not believe any will have a material impact on the Company’s financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Property Plant and Equipment Estimated Useful Lives	Property, plant and equipment are amortized over their estimated useful lives using the straight-line method based on the following rates: Asset Rate Research equipment 5 years Office furniture and equipment 5 years Computer equipment 3 years Leasehold improvements Over the lesser of lease term or

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on a Recurring Basis	The level of the fair value hierarchy utilized to determine the fair va lue of cash and cash equivalents and marketable securities consisted of the following: December 31, 2023 December 31, 2022 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and cash equivalents Cash and money market fund $ 148,643 $ — $ — $ 148,643 $ 57,242 $ — $ — $ 57,242 Marketable securities Guaranteed investment certificates 7,684 — — 7,684 14,953 — — 14,953 U.S. treasuries 252,982 — — 252,982 322,851 — — 322,851 U.S. government securities — 97,912 — 97,912 — 32,479 — 32,479 Commercial paper — 119,108 — 119,108 — 150,560 — 150,560 Corporate debt securities — 304,545 — 304,545 — 142,684 — 142,684 Total $ 409,309 $ 521,565 $ — $ 930,874 $ 395,046 $ 325,723 $ — $ 720,769

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost, Unrealized Gain (Losses) Recognized in AOCI and Fair Value of Available-for-Sale Securities	Amortized cost, unrealized gain (losses) recognized in accumulated other comprehensive income (loss) and fair value of available-for-sale securities consisted of the following: December 31, 2023 December 31, 2022 Amortized Unrealized Gain (Loss) Fair Amortized Unrealized Fair Contractual maturity of 0 to 1 years: Guaranteed investment certificates $ 7,549 $ 135 $ 7,684 $ 14,953 $ — $ 14,953 U.S. treasuries 192,193 ( 249 ) 191,944 78,880 ( 837 ) 78,043 U.S. government securities 98,092 ( 180 ) 97,912 5,793 ( 20 ) 5,773 Commercial paper 119,041 67 119,108 150,560 — 150,560 Corporate debt securities 58,824 100 58,924 8,942 ( 68 ) 8,874 Contractual maturity of 1 to 3 years: U.S. treasuries 53,294 243 53,537 60,354 ( 958 ) 59,396 U.S. government securities — — — 26,741 ( 35 ) 26,706 Corporate debt securities 238,458 797 239,255 42,672 ( 92 ) 42,580 Total $ 767,451 $ 913 $ 768,364 $ 388,895 $ ( 2,010 ) $ 386,885

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment	Property, plant and equipment consisted of the following: December 31, 2023 2022 Research equipment $ 9,111 $ 8,921 Office furniture and equipment 1,285 868 Computer equipment 1,489 1,213 Leasehold improvements 9,019 4,203 Less: accumulated depreciation and amortization ( 11,251 ) ( 8,705 ) Net book value $ 9,653 $ 6,500

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Schedule of Cost Components of Operating Lease	The cost components of the operating leases were as follows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 Lease Cost Operating lease expense $ 1,645 $ 1,126 $ 591 Variable lease expense (1) 787 774 751 Lease Term and Discount Rate Weighted average remaining lease term (years) 7.33 8.07 10.50 Weighted average discount rate 3.87 % 3.97 % 3.42 % (1) Variable lease costs are payments that vary because of changes in facts or circumstances and include common area maintenance and property taxes related to the premises. Variable lease costs are excluded from the calculation of minimum lease payments.
Future Minimum Lease Payments	Future minimum lease payments as of December 31, 2023 were as follows: Year ending December 31: 2024 $ 1,698 2025 1,768 2026 1,837 2027 1,825 2028 1,126 2029 and thereafter 4,283 Total future minimum lease payments $ 12,537 Less: imputed interest ( 1,634 ) Present value of lease liabilities $ 10,903

Accounts Payable and Accrued _2

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses consisted of the following: December 31, 2023 2022 Trade payables $ 8,598 $ 8,491 Employee compensation, benefits, and related accruals 7,425 5,823 Consulting and contracted research 8,824 7,148 Professional fees 780 411 Other 347 341 Total $ 25,974 $ 22,214

Share Capital (Tables)

Share Capital (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock Option Activity	The following table presents the summary of stock option activity for the period: Number of Weighted Aggregate Options Price ($) (1) Intrinsic Value Outstanding, December 31, 2020 4,758,997 9.10 30,464 Granted 1,775,450 19.82 Exercised (2) ( 690,284 ) 7.34 11,306 Forfeited, cancelled or expired ( 205,931 ) 13.01 Outstanding, December 31, 2021 5,638,232 12.55 105,405 Granted 2,315,645 30.90 Exercised (2) ( 780,725 ) 9.47 19,651 Forfeited, cancelled or expired ( 55,370 ) 24.50 Outstanding, December 31, 2022 7,117,782 18.75 147,214 Granted 2,542,473 35.29 Exercised (2) ( 587,536 ) 13.58 14,526 Forfeited, cancelled or expired ( 178,217 ) 31.49 Outstanding, December 31, 2023 8,894,502 23.56 200,122 Exercisable, December 31, 2023 4,789,178 16.23 142,900 (1) Canadian dollar denominated stock options have been translated into U.S. dollars at a foreign exchange rate of 0.76 (2022 – 0.74 and 2021 – 0.79 ) as of December 31, 2023. (2) During the year ended December 31, 2023, 4,320 (2022 – 68,930 and 2021 – 66,215 ) stock options were exercised for the same number of common shares in exchange for cash. In the same period, the Company issued 377,114 (2022 – 510,671 and 2021 – 412,940 ) common shares for the cashless exercise of 583,216 (2022 – 711,795 and 2021 – 624,069 ) stock options.
Schedule of Nonvested Stock Option Activity	A summary of the Company’s non-vested stock option activity and related information for the year ended December 31, 2023 is as follows: Number of Weighted Average Non-vested, January 1, 2023 3,587,374 16.60 Granted 2,542,473 22.52 Vested ( 1,847,714 ) 15.82 Forfeited or cancelled ( 176,809 ) 18.62 Non-vested, December 31, 2023 4,105,324 20.53
Fair Value Assumptions for Stock Options	The weighted-average option pricing assumptions are as follows: Year Ended December 31, 2023 2022 2021 Average risk-free interest rate 3.93 % 2.39 % 1.16 % Expected volatility 69 % 70 % 68 % Average expected term (in years) 5.94 6.16 6.66 Expected dividend yield 0.00 % 0.00 % 0.00 % Weighted average fair value of options granted $ 22.52 $ 19.78 $ 12.54
Stock Based Compensation Expenses	Stock-based compensation expense is classified in the consolidated statements of operations and comprehensive income (loss) as follows: Year Ended December 31, 2023 2022 2021 Research and development expenses $ 13,067 $ 7,766 $ 3,734 General and administrative expenses 19,305 12,610 6,283 $ 32,372 $ 20,376 $ 10,017
Schedule Of Pre-Funded Warrants Activity	The following table summarizes the pre-funded warrants activity for the years ended December 31, 2023, 2022, and 2021: Date of issuance March 2021 October 2021 June 2022 December 2023 Total Outstanding, December 31, 2020 — — — — — Issued 1,081,081 1,694,915 — — 2,775,996 Exercised — — — — — Outstanding, December 31, 2021 1,081,081 1,694,915 — — 2,775,996 Issued — — 327,868 — 327,868 Exercised — — — — — Outstanding, December 31, 2022 1,081,081 1,694,915 327,868 — 3,103,864 Issued — — — 769,230 769,230 Exercised ( 1,081,081 ) ( 618,932 ) — — ( 1,700,013 ) Outstanding, December 31, 2023 — 1,075,983 327,868 769,230 2,173,081

Collaboration Agreements (Table

Collaboration Agreements (Tables)	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule Of Collaboration Revenue	Revenue was as follows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, 2023 2022 2021 Neurocrine Biosciences: Recognition of the transaction price $ — $ 372 $ 3,715 Research and development services — 1,938 6,452 Milestone payments — 7,124 5,270 Pacira BioSciences: Milestone payments — — 3,000 Total revenue $ — $ 9,434 $ 18,437

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Income Tax Recovery	Income tax recovery varies from the amounts that would be computed by applying the expected Canadian federal and provincial statutory income tax rate of 27 % ( 2022 and 2021 – 27 %) to loss before income taxes as shown in the following table: Year Ended December 31, 2023 2022 2021 Computed recoveries at Canadian federal and $ ( 49,325 ) $ ( 33,819 ) $ ( 21,300 ) Change in valuation allowance 43,829 30,732 21,354 Tax credits earned ( 2,868 ) ( 3,086 ) ( 2,279 ) Tax attributes expired/utilized 1,442 1,564 692 Non-deductible expenditures 6,482 4,463 2,033 Other 148 264 ( 506 ) Income tax expense (recovery) $ ( 292 ) $ 118 $ ( 6 )
Schedule of Net Deferred Income Tax Assets	December 31, 2023 2022 2021 Scientific research and experimental development pool $ 38,590 $ 34,891 $ 32,505 Tax credits 30,695 28,835 27,365 Non-capital losses 119,765 80,547 53,453 Depreciable assets 10,311 8,912 7,667 Deferred financing fees 10,831 8,928 7,252 Stock based compensation 3,832 1,492 585 Other 1,220 1,569 732 Less - valuation allowance ( 214,442 ) ( 164,665 ) ( 129,094 ) Net deferred income tax assets $ 802 $ 509 $ 465

Nature of the business (Details

Nature of the business (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 665,140	$ 482,747
Net loss	$ 182,393	$ 125,373	$ 78,882

Basis of Presentation (Details)

Basis of Presentation (Details)	12 Months Ended
	Dec. 31, 2023
Xenon Pharmaceuticals USA Inc. [Member]
Basis of Presentation [Line Items]
Date of incorporation	Dec. 02, 2016

Significant Accounting Polici_4

Significant Accounting Policies - Property Plant and Equipment Estimated Useful Lives (Details)	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]	Leasehold Improvements [Member]
Research Equipment [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Office Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years

Significant Accounting Polici_5

Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Significant Accounting Policies [Line Items]
Impairment of Long-Lived Assets | $	$ 0	$ 0	$ 0
Number of operating segment | Segment	1
Total Revenues [Member] | Neurocrine Biosciences [Member] | Product Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration Risk, Percentage		100%	84%
Total Revenues [Member] | Pacira BioSciences [Member] | Product Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Concentration Risk, Percentage			16%

Net Income (Loss) Per Common _2

Net Income (Loss) Per Common Share (Details)	1 Months Ended
	Mar. 31, 2022 shares
Series1 Preferred Shares
Class Of Stock [Line Items]
Preferred shares, converted	1,016,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - Recurring Basis [Member] - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	$ 930,874	$ 720,769
Level 1 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	409,309	395,046
Level 2 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	521,565	325,723
Cash and Money Market Fund [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Cash and cash equivalents	148,643	57,242
Cash and Money Market Fund [Member] | Level 1 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Cash and cash equivalents	148,643	57,242
Commercial Paper [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	119,108	150,560
Commercial Paper [Member] | Level 2 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	119,108	150,560
U.S. Treasuries [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	252,982	322,851
U.S. Treasuries [Member] | Level 1 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	252,982	322,851
Guaranteed Investment Certificates [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	7,684	14,953
Guaranteed Investment Certificates [Member] | Level 1 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	7,684	14,953
U.S. Government Securities [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	97,912	32,479
U.S. Government Securities [Member] | Level 2 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	97,912	32,479
Corporate Debt Securities [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	304,545	142,684
Corporate Debt Securities [Member] | Level 2 [Member]
Financial Assets Measured at Fair Value on a Recurring Basis [Line Items]
Financial assets	$ 304,545	$ 142,684

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Trading marketable securities	$ 13,867	$ 276,642
Trading securities available-for-sale	$ 768,364	$ 386,885

Marketable Securities - Summary

Marketable Securities - Summary of Amortized Cost, Unrealized Gain (Losses) Recognized in AOCI and Fair Value of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 767,451	$ 388,895
Unrealized Gain (Loss)	913	(2,010)
Fair Value	768,364	386,885
Guaranteed Investment Certificates [Member]
Schedule Of Available For Sale Securities [Line Items]
Contractual maturity of 0 to 1 years, Amortized Cost	7,549	14,953
Contractual maturity of 0 to 1 years, Unrealized Gain (Loss)	135
Contractual maturity of 0 to 1 years, Fair Value	7,684	14,953
U.S. Treasuries [Member]
Schedule Of Available For Sale Securities [Line Items]
Contractual maturity of 0 to 1 years, Amortized Cost	192,193	78,880
Contractual maturity of 0 to 1 years, Unrealized Gain (Loss)	(249)	(837)
Contractual maturity of 0 to 1 years, Fair Value	191,944	78,043
Contractual maturity of 1 to 3 years, Amortized Cost	53,294	60,354
Contractual maturity of 1 to 3 years, Unrealized Gain (Loss)	243	(958)
Contractual maturity of 1 to 3 years, Fair Value	53,537	59,396
U.S. Government Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Contractual maturity of 0 to 1 years, Amortized Cost	98,092	5,793
Contractual maturity of 0 to 1 years, Unrealized Gain (Loss)	(180)	(20)
Contractual maturity of 0 to 1 years, Fair Value	97,912	5,773
Contractual maturity of 1 to 3 years, Amortized Cost		26,741
Contractual maturity of 1 to 3 years, Unrealized Gain (Loss)		(35)
Contractual maturity of 1 to 3 years, Fair Value		26,706
Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Contractual maturity of 0 to 1 years, Amortized Cost	119,041	150,560
Contractual maturity of 0 to 1 years, Unrealized Gain (Loss)	67
Contractual maturity of 0 to 1 years, Fair Value	119,108	150,560
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Contractual maturity of 0 to 1 years, Amortized Cost	58,824	8,942
Contractual maturity of 0 to 1 years, Unrealized Gain (Loss)	100	(68)
Contractual maturity of 0 to 1 years, Fair Value	58,924	8,874
Contractual maturity of 1 to 3 years, Amortized Cost	238,458	42,672
Contractual maturity of 1 to 3 years, Unrealized Gain (Loss)	797	(92)
Contractual maturity of 1 to 3 years, Fair Value	$ 239,255	$ 42,580

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Less: accumulated depreciation and amortization	$ (11,251)	$ (8,705)
Net book value	9,653	6,500
Research Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	9,111	8,921
Office Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	1,285	868
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	1,489	1,213
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment	$ 9,019	$ 4,203

Leases (Details)

Leases (Details)	12 Months Ended
	Dec. 31, 2023 Lease Option	Oct. 31, 2022
Burnaby, British Columbia [Member]
Lessee Lease Description [Line Items]
Number of operating leases | Lease	1
Operating lease, number of renewal options | Option	2
Operating lease expiration date	Jun. 30, 2032
Operating lease, description	The Company has an operating lease for research laboratories and office space in Burnaby, British Columbia which expires on June 30, 2032, and two renewal options for 5-years each which were not considered in the determination of the right-of-use asset and lease liability
Burnaby, British Columbia [Member] | First Renewal Option [Member]
Lessee Lease Description [Line Items]
Operating lease extension term	5 years
Burnaby, British Columbia [Member] | Second Renewal Option [Member]
Lessee Lease Description [Line Items]
Operating lease extension term	5 years
Needham Massachusetts [Member]
Lessee Lease Description [Line Items]
Operating lease term		62 months
Operating lease, description	The Company has an additional operating lease for office space in Needham, Massachusetts ("Needham Lease"), which commenced in October 2022. The Needham Lease is for a 62-month term and an option to terminate one year prior to the expiry date, which was not considered in the determination of the right-of-use asset and lease liability.
Operating lease, option to terminate	option to terminate one year prior to the expiry date

Leases - Schedule of Cost Compo

Leases - Schedule of Cost Components of Operating Lease (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease expense	$ 1,645	$ 1,126	$ 591
Variable lease expense	$ 787	$ 774	$ 751
Weighted average remaining lease term (years)	7 years 3 months 29 days	8 years 25 days	10 years 6 months
Weighted average discount rate	3.87%	3.97%	3.42%

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2024	$ 1,698
2025	1,768
2026	1,837
2027	1,825
2028	1,126
2029 and thereafter	4,283
Total future minimum lease payments	12,537
Less: imputed interest	(1,634)
Present value of lease liabilities	$ 10,903

Accounts Payable and Accrued _3

Accounts Payable and Accrued Expenses - Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Trade payables	$ 8,598	$ 8,491
Employee compensation, benefits, and related accruals	7,425	5,823
Consulting and contracted research	8,824	7,148
Professional fees	780	411
Other	347	341
Total	$ 25,974	$ 22,214

Share Capital (Details)

Share Capital (Details) - USD ($) $ / shares in Units, $ in Thousands

1 Months Ended

12 Months Ended

Nov. 30, 2023

Jun. 30, 2022

Mar. 31, 2022

Jan. 31, 2022

Oct. 31, 2021

Sep. 30, 2021

Mar. 31, 2021

Jan. 31, 2021

Jun. 30, 2020

Sep. 30, 2019

Mar. 31, 2018

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2018

Aug. 31, 2018

Share Capital [Line Items]

Warrants outstanding to purchase common stock

2,173,081

3,103,864

2,775,996

Options granted

2,542,473

2,315,645

1,775,450

Options Outstanding Weighted Average Remaining Contractual Life in Years

7 years 4 months 24 days

Options Exercisable Weighted Average Remaining Contractual Life in Years

6 years 2 months 12 days

Aggregate fair value of options vested

$ 29,233

$ 13,752

$ 8,271

Unrecognized stock-based compensation cost

$ 70,691

Unrecognized stock-based compensation expected to be recognized over a period

2 years 7 months 9 days

Number of warrants exercised

(1,700,013)

0

Warrants exercise description

The Company may not affect the exercise of any pre-funded warrant, and a holder will not be entitled to exercise any portion of any pre-funded warrant that, upon giving effect to such exercise, would cause: (i) the aggregate number of common shares beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the total number of common shares outstanding immediately after giving effect to the exercise; or (ii) the combined voting power of the Company’s securities beneficially owned by such holder, together with its affiliates, to exceed 4.99% of the combined voting power of all of the Company’s securities immediately outstanding after giving effect to the exercise, which percentage may be changed at the holder’s election to a higher or lower percentage not in excess of 19.99% upon at least 61 days’ notice to the Company.

Term Loans [Member]

Share Capital [Line Items]

Warrants outstanding to purchase common stock

40,000

40,000

Warrants exercise price per common share

$ 9.79

Amended and Restated Stock Option Plan [Member]

Share Capital [Line Items]

Vesting period

4 years

Maximum term of each option exercised

10 years

Options granted

0

2019 Inducement Plan [Member]

Share Capital [Line Items]

Options granted

0

Common shares reserved for issuance

400,000

Amended and Restated 2014 Plan [Member]

Share Capital [Line Items]

Vesting period

4 years

Maximum term of each option exercised

10 years

Common shares reserved for issuance

9,300,000

3,460,724

Number of restricted share awards, restricted share unit awards or performance awards available for issue

1,000,000

Common Shares [Member]

Share Capital [Line Items]

Shares issued

10,701,842

9,357,348

16,143,472

Conversion of shares

1,016,000

1,016,000

1,852,000

Common stock issued upon conversion of pre-funded warrants

1,700,000

Pre-funded warrants exercised

1,700,013

March 2021

Share Capital [Line Items]

Warrants issued price per pre funded warrant

$ 18.4999

Warrants exercise price per common share

$ 0.0001

Number of warrants exercised

(1,081,081)

October 2021

Share Capital [Line Items]

Warrants issued price per pre funded warrant

$ 29.4999

Warrants exercise price per common share

$ 0.0001

Number of warrants exercised

(618,932)

June 2022

Share Capital [Line Items]

Warrants issued price per pre funded warrant

$ 30.4999

Warrants exercise price per common share

0.0001

December 2023

Share Capital [Line Items]

Warrants issued price per pre funded warrant

32.4999

Warrants exercise price per common share

$ 0.0001

Jefferies and Stifel [Member] | ATM [Member]

Share Capital [Line Items]

Sale proceeds of common shares

$ 10,693

$ 29,508

Jefferies and Stifel [Member] | ATM [Member] | Maximum [Member]

Share Capital [Line Items]

Gross proceeds from issuable of common stock

$ 250,000

Jefferies and Stifel [Member] | ATM [Member] | Common Shares [Member]

Share Capital [Line Items]

Shares issued

733,000

855,685

Jefferies and Stifel [Member] | Underwritten Public Offering [Member]

Share Capital [Line Items]

Sale proceeds of common shares

$ 107,922

Shares issued

5,135,135

Shares price

$ 18.50

Warrants outstanding to purchase common stock

1,081,081

Warrants issued price per pre funded warrant

$ 18.4999

Warrants exercise price per common share

$ 0.0001

Sale proceeds from issuance of pre funded warrants

$ 23,477

$ 9,387

$ 65,716

Jefferies and Stifel [Member] | Over Allotment [Member]

Share Capital [Line Items]

Shares issued

810,810

Jefferies LLC SVB Leerink LLC and Stifel Nicolaus Company Incorporated [Member] | Underwritten Public Offering [Member]

Share Capital [Line Items]

Sale proceeds of common shares

$ 323,938

Shares issued

10,000,000

Shares price

$ 29.50

Warrants outstanding to purchase common stock

1,694,915

Warrants issued price per pre funded warrant

$ 29.4999

Warrants exercise price per common share

$ 0.0001

Jefferies LLC SVB Leerink LLC and Stifel Nicolaus Company Incorporated [Member] | Over Allotment [Member]

Share Capital [Line Items]

Shares issued

1,525,423

Neurocrine Biosciences [Member] | License and Collaboration Agreement [Member]

Share Capital [Line Items]

Sale proceeds of common shares

$ 8,250

$ 5,500

Shares issued

258,986

275,337

Aggregate purchase price per share

$ 31.855

$ 19.9755

Premium

$ 374

$ 770

Jefferies, Stifel, J.P. Morgan Securities LLC and SVB Securities LLC [Member] | Underwritten Public Offering [Member]

Share Capital [Line Items]

Sale proceeds of common shares

$ 269,890

Shares issued

9,098,362

Shares price

$ 30.50

Warrants outstanding to purchase common stock

327,868

Warrants issued price per pre funded warrant

$ 30.4999

Warrants exercise price per common share

$ 0.0001

Jefferies, Stifel, J.P. Morgan Securities LLC and SVB Securities LLC [Member] | Over Allotment [Member]

Share Capital [Line Items]

Shares issued

1,229,508

J.P. Morgan, Jefferies, BofA Securities, Inc., Stifel, and RBC Capital Markets, LLC [Member] | Underwritten Public Offering [Member]

Share Capital [Line Items]

Sale proceeds of common shares

$ 323,979

Shares issued

9,846,157

Shares price

$ 32.5

Warrants outstanding to purchase common stock

769,230

Warrants issued price per pre funded warrant

$ 32.4999

Warrants exercise price per common share

$ 0.0001

J.P. Morgan, Jefferies, BofA Securities, Inc., Stifel, and RBC Capital Markets, LLC [Member] | Over Allotment [Member]

Share Capital [Line Items]

Shares issued

1,384,615

Series1 Preferred Shares

Share Capital [Line Items]

Conversion of shares

1,016,000

1,852,000

BVF Partners L.P [Member] | Exchange Agreement [Member] | Common Shares [Member]

Share Capital [Line Items]

Shares cancelled

2,868,000

BVF Partners L.P [Member] | Exchange Agreement [Member] | Series1 Preferred Shares

Share Capital [Line Items]

Preferred shares convertible into common shares

one-for-one

Shares issued

2,868,000

Share Capital - Stock Option Ac

Share Capital - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-Based Payment Arrangement [Abstract]
Number of Options Outstanding, Beginning balance	7,117,782	5,638,232	4,758,997
Number of Options, Granted	2,542,473	2,315,645	1,775,450
Number of Options, Exercised	(587,536)	(780,725)	(690,284)
Number of Options, Forfeited, cancelled or expired	(178,217)	(55,370)	(205,931)
Number of Options Outstanding, Ending balance	8,894,502	7,117,782	5,638,232
Number of Options Exercisable, End of period	4,789,178
Weighted Average Exercise Price Outstanding, Beginning balance	$ 18.75	$ 12.55	$ 9.10
Weighted Average Exercise Price, Granted	35.29	30.90	19.82
Weighted Average Exercise Price, Exercised	13.58	9.47	7.34
Weighted Average Exercise Price, Forfeited, cancelled and expired	31.49	24.50	13.01
Weighted Average Exercise Price Outstanding, Ending balance	23.56	$ 18.75	$ 12.55
Weighted Average Exercise Price, Exercisable Ending balance	$ 16.23
Aggregate Intrinsic Value, Outstanding	$ 200,122	$ 147,214	$ 105,405	$ 30,464
Aggregate Intrinsic Value, Exercised	14,526	$ 19,651	$ 11,306
Aggregate Intrinsic Value, Exercisable, Ending balance	$ 142,900

Share Capital - Stock Option _2

Share Capital - Stock Option Activity (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2023 shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares
Share-Based Payment Arrangement [Abstract]
Foreign exchange rate translation	0.76	0.74	0.79
Stock Options exercised for Number of Common Shares for cash	4,320	68,930	66,215
Common stock issued for cashless exercise	377,114	510,671	412,940
Cashless exercise of stock options	583,216	711,795	624,069

Share Capital - Summary of Non-

Share Capital - Summary of Non-Vested Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Number of Options, Non-vested, Beginning balance	3,587,374
Number of Options, Granted	2,542,473	2,315,645	1,775,450
Number of Options, Vested	(1,847,714)
Number of Options, Forfeited or cancelled	(176,809)
Number of Options, Non-vested, Ending balance	4,105,324	3,587,374
Weighted Average Grant Date Fair Value, Non-vested, Beginning balance	$ 16.6
Weighted Average Grant Date Fair Value, Granted	22.52	$ 19.78	$ 12.54
Weighted Average Grant Date Fair Value, Vested	15.82
Weighted Average Grant Date Fair Value, Forfeited or cancelled	18.62
Weighted Average Grant Date Fair Value, Non-vested, Ending balance	$ 20.53	$ 16.6

Share Capital - Fair Value Assu

Share Capital - Fair Value Assumptions for Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assumptions For Stock Options [Abstract]
Average risk-free interest rate	3.93%	2.39%	1.16%
Expected volatility	69%	70%	68%
Average expected term (in years)	5 years 11 months 8 days	6 years 1 month 28 days	6 years 7 months 28 days
Expected dividend yield	0%	0%	0%
Weighted average fair value of options granted	$ 22.52	$ 19.78	$ 12.54

Share Capital - Stock Based Com

Share Capital - Stock Based Compensation Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 32,372	$ 20,376	$ 10,017
Research and development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	13,067	7,766	3,734
General and administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 19,305	$ 12,610	$ 6,283

Share Capital - Schedule of Pre

Share Capital - Schedule of Pre-Funded Warrants (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Capital [Line Items]
Outstanding, beginning	3,103,864	2,775,996
Issued	769,230	327,868	2,775,996
Exercised	(1,700,013)	0
Outstanding, ending	2,173,081	3,103,864	2,775,996
March 2021
Share Capital [Line Items]
Outstanding, beginning	1,081,081	1,081,081
Issued			1,081,081
Exercised	(1,081,081)
Outstanding, ending		1,081,081	1,081,081
October 2021
Share Capital [Line Items]
Outstanding, beginning	1,694,915	1,694,915
Issued			1,694,915
Exercised	(618,932)
Outstanding, ending	1,075,983	1,694,915	1,694,915
June 2022
Share Capital [Line Items]
Outstanding, beginning	327,868
Issued		327,868
Outstanding, ending	327,868	327,868
December 2023
Share Capital [Line Items]
Issued	769,230
Outstanding, ending	769,230

Collaboration Agreements - Sche

Collaboration Agreements - Schedule of Collaboration Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue	$ 9,434	$ 18,437
Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue	9,434	18,437
Neurocrine Biosciences [Member] | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Recognition of the transaction price	372	3,715
Research and development services	1,938	6,452
Milestone payments	7,124	5,270
Total revenue	$ 2,310	10,167
Pacira BioSciences [Member] | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments		$ 3,000

Collaboration Agreements (Detai

Collaboration Agreements (Details) - USD ($)	1 Months Ended			12 Months Ended
	Jan. 31, 2022	Sep. 30, 2021	Dec. 31, 2019	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2019
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue					$ 9,434,000	$ 18,437,000
Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue					9,434,000	18,437,000
Neurocrine Biosciences [Member] | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue					2,310,000	10,167,000
Research and development services					1,938,000	6,452,000
Milestone payments					7,124,000	5,270,000
Neurocrine Biosciences [Member] | Development Services Under the Initial Development Program for the DTCs [Member] | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue					372,000	3,715,000
Neurocrine Biosciences [Member] | Research And Development Funding | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development services					$ 1,938,000	6,452,000
Neurocrine Biosciences [Member] | License and Collaboration Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from upfront fee			$ 50,000,000
Upfront payment received in cash			30,000,000				$ 30,000,000
Upfront payment received in equity investment			$ 20,000,000				20,000,000
Potential milestone payments receivable				$ 1,667,500,000
Percentage of option to co-fund development costs upon achievement of certain milestones				50%
Collaborate agreement premium related to equity investment							3,333,000
Transaction price allocated to performance obligations							33,333,000
Milestone Payment Received	$ 15,000,000	$ 10,000,000
Milestone Payment Received in Cash	6,750,000	4,500,000
Milestone Payment Received in Equity Investment	8,250,000	5,500,000
Equity investment measure at fair value	7,876,000	4,730,000
Premium	374,000	770,000
Performance obligation related to milestone	0	0
Revenue	$ 6,750,000	$ 4,500,000
Neurocrine Biosciences [Member] | License and Collaboration Agreement [Member] | Exclusive License to XEN901 and Exclusive License to DTCs [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction price allocated to performance obligations							$ 28,807,000
Neurocrine Biosciences [Member] | License and Collaboration Agreement [Member] | Development Services Under the Initial Development Program for the DTCs [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction price allocated to performance obligations				$ 5,025,000
Variable consideration allocated to performance obligation				499,000
Neurocrine Biosciences [Member] | License and Collaboration Agreement [Member] | Regulatory Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments receivable				1,067,500,000
Neurocrine Biosciences [Member] | License and Collaboration Agreement [Member] | Sales Based Milestone [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments receivable				$ 600,000,000
Pacira BioSciences [Member] | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments						3,000,000
Pacira BioSciences [Member] | Asset Purchase Agreement [Member] | XEN402 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments						1,000,000
Milestone payment due on initiation of Phase 1b clinical trial						$ 2,000,000

Commitments and Contingencies (

Commitments and Contingencies (Details) - Asset Purchase Agreement [Member] - 1st Order Pharmaceuticals, Inc. [Member]	12 Months Ended
	Dec. 31, 2023 USD ($)
Commitments And Contingencies [Line Items]
Milestone payment paid	$ 2,000,000
Royalty obligations	0
Regulatory Milestone [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Future potential payments	$ 6,000,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Tax Credit Carryforward [Line Items]
Unclaimed Tax Deductions Related To Scientific Research And Experimental Development Expenditures	$ 142,925	$ 129,226
Non-capital losses carried forward for tax purposes	$ 422,822	295,828
Tax Credit Carry forward, Expiration Date	Dec. 31, 2043
Unrecognized tax benefits of uncertain tax positions		$ 10,850
Canadian federal and provincial tax rates	27%	27%	27%
Canada and United States Revenue Agency [Member] | Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2022
Canada and United States Revenue Agency [Member] | Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Tax year open for income tax examination	2003
Investment Tax credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset taxes payable	$ 29,074	$ 27,323
Provincial Tax Credit [Member]
Tax Credit Carryforward [Line Items]
Tax credit available to offset taxes payable	$ 8,099	$ 8,418

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Recovery (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Computed recoveries at Canadian federal and provincial tax rates	$ (49,325)	$ (33,819)	$ (21,300)
Change in valuation allowance	43,829	30,732	21,354
Tax credits earned	(2,868)	(3,086)	(2,279)
Tax attributes expired/utilized	1,442	1,564	692
Non-deductible expenditures	6,482	4,463	2,033
Other	148	264	(506)
Income tax expense (recovery)	$ (292)	$ 118	$ (6)

Income Taxes - Net Deferred Inc

Income Taxes - Net Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Scientific research and experimental development pool	$ 38,590	$ 34,891	$ 32,505
Tax credits	30,695	28,835	27,365
Non-capital losses	119,765	80,547	53,453
Depreciable assets	10,311	8,912	7,667
Deferred financing fees	10,831	8,928	7,252
Stock based compensation	3,832	1,492	585
Other	1,220	1,569	732
Less - valuation allowance	(214,442)	(164,665)	(129,094)
Net deferred income tax assets	$ 802	$ 509	$ 465