Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Total revenues	$ 1,609	$ 1,958	$ 4,252	$ 5,752
Operating expenses:
Research and development	10,018	7,453	27,545	34,795
General and administrative	3,151	4,024	9,466	18,022
Acquired in-process research and development	0	65,045	0	65,045
Total operating expenses	13,169	76,522	37,011	117,862
Loss from operations	(11,560)	(74,564)	(32,759)	(112,110)
Other income:
Interest income and other, net	149	834	912	3,037
Net loss	(11,411)	(73,730)	(31,847)	(109,073)
Other comprehensive loss:
Unrealized (loss)/gain on debt investments, net	(97)	(36)	(2)	182
Comprehensive loss	$ (11,508)	$ (73,766)	$ (31,849)	$ (108,891)
Per share information:
Net loss, basic and diluted (in dollars per share)	$ (0.18)	$ (1.26)	$ (0.51)	$ (2.04)
Weighted-average shares outstanding, basic and diluted (in shares)	62,242,456	58,457,110	62,009,941	53,519,207
Contract revenue
Total revenues	$ 1,591	$ 1,958	$ 4,158	$ 5,752
Licensing revenue
Total revenues	$ 18	$ 0	$ 94	$ 0