Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenue (note 13)	$ 9,434	$ 18,437	$ 32,166
Operating expenses:
Research and development	105,767	75,463	50,523
General and administrative	32,810	21,967	12,944
Total operating expenses	138,577	97,430	63,467
Loss from operations	(129,143)	(78,993)	(31,301)
Other income (expense):
Interest income	8,713	466	2,279
Unrealized fair value (loss) gain on trading securities	(2,934)	(719)	4
Interest expense			(484)
Foreign exchange (loss) gain	(1,891)	358	1,396
Loss on repayment of term loan (note 11)	0	0	(988)
Other income (expense)	3,888	105	2,207
Loss before income taxes	(125,255)	(78,888)	(29,094)
Income tax (expense) recovery (note 15)	(118)	6	257
Net loss	(125,373)	(78,882)	(28,837)
Net loss attributable to preferred shareholders	(437)	(1,795)	(824)
Net loss attributable to common shareholders	(124,936)	(77,087)	(28,013)
Other comprehensive loss:
Unrealized loss on available-for-sale securities (note 7)	(2,010)
Comprehensive loss	$ (127,383)	$ (78,882)	$ (28,837)
Net loss per common share (note 5):
Basic	$ (2.06)	$ (1.77)	$ (0.81)
Diluted	$ (2.06)	$ (1.77)	$ (0.81)
Weighted-average common shares outstanding (note 5):
Basic	60,542,142	43,627,452	34,542,213
Diluted	60,542,142	43,627,452	34,542,213