Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Total revenues	$ 391	$ 1,402	$ 1,826	$ 2,643
Operating expenses:
Research and development	13,798	8,578	25,660	17,527
General and administrative	4,408	3,110	8,544	6,315
Acquired in-process research and development	0	0	82,890	0
Total operating expenses	18,206	11,688	117,094	23,842
Loss from operations	(17,815)	(10,286)	(115,268)	(21,199)
Other income:
Interest income and other, net	52	270	90	763
Net loss	(17,763)	(10,016)	(115,178)	(20,436)
Other comprehensive loss:
Unrealized gain (loss) on debt investments, net	32	141	(11)	95
Comprehensive loss	$ (17,731)	$ (9,875)	$ (115,189)	$ (20,341)
Per share information:
Net loss, basic (in dollars per share)	$ (0.21)	$ (0.16)	$ (1.38)	$ (0.33)
Net loss, diluted (in dollars per share)	$ (0.21)	$ (0.16)	$ (1.38)	$ (0.33)
Weighted-average shares outstanding, basic (in shares)	86,225,836	62,042,778	83,231,600	61,892,407
Weighted-average shares outstanding, diluted (in shares)	86,225,836	62,042,778	83,231,600	61,892,407
Contract and grant revenue
Total revenues	$ 390	$ 1,396	$ 1,823	$ 2,567
Licensing revenue
Total revenues	$ 1	$ 6	$ 3	$ 76