Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Total revenue	$ 9,266	$ 5,785	$ 22,993	$ 15,375
Operating expenses:
Research and development	21,067	35,992	80,711	83,956
General and administrative	5,219	4,226	15,187	13,128
Total operating expenses	26,286	40,218	95,898	97,084
Operating loss	(17,020)	(34,433)	(72,905)	(81,709)
Other income, net	379	1,261	1,970	3,297
Loss before benefit from income taxes	(16,641)	(33,172)	(70,935)	(78,412)
Benefit from income taxes	132	330	436	650
Net loss	$ (16,509)	$ (32,842)	$ (70,499)	$ (77,762)
Net loss per share:
Basic and Diluted	$ (0.35)	$ (0.74)	$ (1.51)	$ (1.88)
Weighted average shares:
Basic and Diluted	46,885,424	44,517,134	46,803,659	41,314,044
Other comprehensive income (loss), net of tax of $0:
Change in unrealized gains (losses) on available-for-sale marketable securities	$ (272)	$ (12)	$ 193	$ 267
Total comprehensive loss	(16,781)	(32,854)	(70,306)	(77,495)
License and Milestone Fees
Revenue:
Total revenue	9,257	$ 5,785	22,377	15,235
Clinical Compound Revenue
Revenue:
Total revenue	$ 9		$ 616	$ 140