Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue
Collaborations, licenses, milestones, and royalties	$ 164,579	$ 275,111	$ 122,694
Operating expenses
Research and development	199,563	192,507	169,802
General and administrative	47,489	38,837	29,689
Total operating expenses	247,052	231,344	199,491
Income (loss) from operations	(82,473)	43,767	(76,797)
Other income (expense)
Interest income, net	4,817	849	7,264
Other income (expense), net	(286)	(1,274)	95
Gain on equity securities, net	23,434	39,289	105
Total other income, net	27,965	38,864	7,464
Income (loss) before income tax	(54,508)	82,631	(69,333)
Income tax expense	673	0	0
Net income (loss)	(55,181)	82,631	(69,333)
Other comprehensive income (loss)
Net unrealized loss on marketable securities available-for-sale	(5,442)	(1,584)	(1,087)
Comprehensive income (loss)	$ (60,623)	$ 81,047	$ (70,420)
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.93)	$ 1.42	$ (1.21)
Diluted (in dollars per share)	$ (0.93)	$ 1.37	$ (1.21)
Weighted average shares used to compute net income (loss) per share attributable to common stockholders:
Basic (in shares)	59,652,461	58,379,641	57,212,737
Diluted (in shares)	59,652,461	60,495,455	57,212,737