Condensed Consolidated Statements of Loss and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue
Research and development collaborations (note 9)	$ 644	$ 8,269
Operating expenses:
Research and development	44,283	36,943
General and administrative	1,296	7,206
Total operating expenses	45,579	44,149
Loss from operations	(44,935)	(35,880)
Other income (expense):
Interest income	741	1,869
Other income, net (note 10)	129	3,250
Total other income, net	870	5,119
Loss before income taxes	(44,065)	(30,761)
Income tax expense	(525)	(375)
Net loss and comprehensive loss	$ (44,590)	$ (31,136)
Net loss per common share (note 4):
Basic and diluted (in dollars per share)	$ (0.87)	$ (0.64)
Weighted-average common shares outstanding (note 4):
Basic and diluted (in shares)	51,367,663	48,686,718