Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue:
Total revenue	$ 5,634	$ 5,208	$ 13,727	$ 9,590
Operating expenses:
Research and development	26,108	24,356	59,644	47,964
General and administrative	5,410	4,994	9,968	8,902
Total operating expenses	31,518	29,350	69,612	56,866
Operating loss	(25,884)	(24,142)	(55,885)	(47,276)
Other income, net	634	947	1,591	2,036
Loss before benefit from income taxes	(25,250)	(23,195)	(54,294)	(45,240)
Benefit from income taxes	182	235	304	320
Net loss	$ (25,068)	$ (22,960)	$ (53,990)	$ (44,920)
Net loss per share:
Basic and Diluted	$ (0.54)	$ (0.58)	$ (1.15)	$ (1.13)
Weighted average shares:
Basic and Diluted	46,799,703	39,818,162	46,762,327	39,685,954
Other comprehensive income, net of tax of $0:
Change in unrealized gains (losses) on available-for-sale marketable securities	$ 703	$ 92	$ 465	$ 279
Total comprehensive loss	(24,365)	(22,868)	(53,525)	(44,641)
License and Milestone Fees
Revenue:
Total revenue	5,099	$ 5,208	13,120	9,450
Clinical Compound Revenue
Revenue:
Total revenue	$ 535		$ 607	$ 140