Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Statement [Abstract]
Collaboration revenue (note 9)	$ 0	$ 0	$ 7,500	$ 0
Operating expenses:
Research and development	74,985	49,702	136,185	93,952
General and administrative	19,244	19,402	38,282	34,193
Total operating expenses	94,229	69,104	174,467	128,145
Loss from operations	(94,229)	(69,104)	(166,967)	(128,145)
Other income:
Interest income	7,199	10,837	15,282	22,192
Foreign exchange gain	1,698	10	1,733	177
Total other income	8,897	10,847	17,015	22,369
Loss before income taxes	(85,332)	(58,257)	(149,952)	(105,776)
Income tax recovery (expense)	626	333	199	(79)
Net loss	(84,706)	(57,924)	(149,753)	(105,855)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities (note 5)	949	(443)	1,725	(2,135)
Comprehensive loss	$ (83,757)	$ (58,367)	$ (148,028)	$ (107,990)
Net loss per common share (note 10):
Basic	$ (1.07)	$ (0.75)	$ (1.9)	$ (1.36)
Diluted	$ (1.07)	$ (0.75)	$ (1.9)	$ (1.36)
Weighted-average common shares outstanding (note 10):
Basic	78,953,445	77,671,128	78,820,474	77,632,864
Diluted	78,953,445	77,671,128	78,820,474	77,632,864