Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer, Including Assessed Tax	$ 7,379	$ 107
Operating expenses:
Research and development	68,142	81,054
General and administrative	22,584	29,386
Impairment of intangible assets	0	4,254
Total operating expenses	90,726	114,694
Operating loss	(83,347)	(114,587)
Other income (expense):
Interest income	2,652	1,247
Non-cash interest expense related to sale of future royalties	(1,447)	(1,305)
Gain on remeasurement of future royalty liability	0	6,960
Other expense, net	(62)	(6)
Loss before income taxes	(82,204)	(107,691)
Provision for income taxes	261	67
Net loss	$ (82,465)	$ (107,758)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.57)	$ (0.84)
Shares used to compute net loss per share, basic and diluted (in shares)	144,819,781	127,683,813
Comprehensive loss:
Net loss	$ (82,465)	$ (107,758)
Unrealized gain (loss) on available-for-sale investments, net of tax	298	(225)
Comprehensive loss	(82,167)	(107,983)
Non Cash Royalty Revenue [Member]
Revenue from Contract with Customer, Including Assessed Tax	3,920	107
Grant [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 3,459	$ 0