CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONSOLIDATED STATEMENT OF COMPREHENSIVE LOSS
Revenue	$ 3,900	$ 5,039	$ 8,930	$ 8,145
Operating expenses:
Research and development	16,997	13,715	33,899	24,454
General and administrative	6,365	4,710	12,187	8,780
Total operating expenses	23,362	18,425	46,086	33,234
Loss from operations	(19,462)	(13,386)	(37,156)	(25,089)
Other income (expense), net	181	861	805	1,809
Net loss	$ (19,281)	$ (12,525)	$ (36,351)	$ (23,280)
Net loss per share, basic and diluted (in dollars per share)	$ (0.65)	$ (0.48)	$ (1.23)	$ (0.90)
Weighted average common shares outstanding, basic and diluted (in shares)	29,690,280	25,922,833	29,608,814	25,758,658
Comprehensive loss:
Net loss	$ (19,281)	$ (12,525)	$ (36,351)	$ (23,280)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities	(185)	42	12	66
Total other comprehensive income (loss)	(185)	42	12	66
Comprehensive loss	$ (19,466)	$ (12,483)	$ (36,339)	$ (23,214)