Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities:
Net loss	$ (137,650)	$ (87,978)
Items not involving cash:
Depreciation	2,690	1,109
Deferred income tax recovery	(92)	(49)
Stock-based compensation	23,190	14,564
Unrealized foreign exchange (gain) loss	(753)	3,454
Unrealized fair value (gain) loss on trading securities	(3,404)	4,944
Changes in operating assets and liabilities:
Accounts receivable	424	242
Prepaid expenses and other current assets	4,103	(4,028)
Accounts payable and accrued expenses	1,630	2,044
Net cash used in operating activities	(109,862)	(65,698)
Investing activities:
Purchases of property, plant and equipment	(5,539)	(1,142)
Purchases of marketable securities	(417,319)	(436,393)
Proceeds from marketable securities	545,414	155,867
Net cash provided by (used in) investing activities	122,556	(281,668)
Financing activities:
Issuance of common shares and pre-funded warrants, net of issuance costs (note 8a and note 8c)	29,508	277,766
Issuance of common shares pursuant to exercise of stock options		699
Net cash provided by financing activities	29,508	278,465
Effect of exchange rate changes on cash and cash equivalents	130	(3,298)
Increase (decrease) in cash and cash equivalents	42,332	(72,199)
Cash and cash equivalents, beginning of period	57,242	175,688
Cash and cash equivalents, end of period	99,574	103,489
Supplemental disclosures:
Cash paid for operating lease	1,219	638
Cash received for lease incentives	1,265
Supplemental disclosures of non-cash transactions:
Fair value of stock options exercised on a cashless basis	3,183	$ 4,085
Fair value of pre-funded warrants exercised	24,141
Increase in operating lease liability and accounts receivable related to lease incentives claimed in the period	$ 226