CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating expenses:
Research and development	$ 9,446	$ 16,172
General and administrative	7,220	5,408
Total operating expenses	16,666	21,580
Loss from operations	(16,666)	(21,580)
Interest income	68	556
Net loss	$ (16,598)	$ (21,024)
Net loss per share, basic and diluted (in dollars per share)	$ (0.58)	$ (0.76)
Weighted average common shares outstanding, basic and diluted (in shares)	28,535,948	27,651,067
Comprehensive loss:
Net loss	$ (16,598)	$ (21,024)
Other comprehensive income:
Unrealized gains on marketable securities	0	67
Total other comprehensive income	0	67
Comprehensive loss	$ (16,598)	$ (20,957)