Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities:
Net loss	$ (41,727)	$ (19,670)
Items not involving cash:
Depreciation	354	376
Deferred income tax expense	288	258
Stock-based compensation	5,994	3,614
Unrealized foreign exchange gain	(5)	(142)
Unrealized fair value (gain) loss on trading securities	(1,878)	3,362
Changes in operating assets and liabilities:
Accounts receivable	226	(155)
Prepaid expenses and other current assets	2,931	(272)
Accounts payable and accrued expenses	(594)	(5,799)
Net cash used in operating activities	(34,411)	(18,428)
Investing activities:
Purchases of property, plant and equipment	(2,206)	(212)
Purchases of marketable securities	(108,282)	(68,956)
Proceeds from marketable securities	157,110	20,280
Net cash provided by (used in) investing activities	46,622	(48,888)
Financing activities:
Issuance of common shares, net of issuance costs (note 8a)		7,876
Net cash provided by financing activities		7,876
Effect of exchange rate changes on cash and cash equivalents	59	293
Increase (decrease) in cash and cash equivalents	12,270	(59,147)
Cash and cash equivalents, beginning of period	57,242	175,688
Cash and cash equivalents, end of period	69,512	116,541
Supplemental disclosures:
Interest received	3,098	1,682
Cash paid for operating lease	406	203
Supplemental disclosures of non-cash transactions:
Fair value of stock options exercised on a cashless basis	635	$ 1,529
Fair value of pre-funded warrants exercised	7,379
Increase in operating lease liability and accounts receivable related to lease incentives claimed in the period	$ 1,482