Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Total revenue	$ 8,093	$ 4,382
Operating expenses:
Research and development	33,536	23,608
General and administrative	4,558	3,908
Total operating expenses	38,094	27,516
Operating loss	(30,001)	(23,134)
Other income, net	957	1,089
Loss before benefit from income taxes	(29,044)	(22,045)
Benefit from income taxes	122	85
Net loss	$ (28,922)	$ (21,960)
Net loss per share:
Basic and Diluted	$ (0.62)	$ (0.56)
Weighted average shares:
Basic and Diluted	46,724,951	39,552,277
Other comprehensive income (loss), net of tax of $0:
Change in unrealized gains (losses) on available-for-sale marketable securities	$ (238)	$ 187
Total comprehensive loss	(29,160)	(21,773)
License and Milestone Fees [Member]
Revenue:
Total revenue	8,021	4,242
Clinical Compound Revenue [Member]
Revenue:
Total revenue	$ 72	$ 140