Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Collaboration and license revenue	$ 2,697	$ 351
Operating expenses:
Research and development	26,252	25,697
General and administrative	7,868	9,543
Change in fair value of contingent consideration and contingent value rights liabilities	(1,038)	1,839
Amortization of intangible assets	429	420
Total operating expenses	33,511	37,499
Loss from operations	(30,814)	(37,148)
Other expense, net	(95)	(67)
Loss before income taxes and share of net loss of equity method investment	(30,909)	(37,215)
Share of net loss of equity method investment	(775)
Net loss	$ (31,684)	$ (37,215)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.54)	$ (0.88)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	58,340	42,136
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax of $0	$ 107	$ 38
Unrealized gain (loss) on marketable debt securities, net of tax of $0	(1,589)	16
Total other comprehensive income (loss)	(1,482)	54
Comprehensive loss	$ (33,166)	$ (37,161)