Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
OPERATING EXPENSES:
Research and development	$ 7,271	$ 6,874
General and administrative	5,196	1,855
Total operating expenses	12,467	8,729
LOSS FROM OPERATIONS	(12,467)	(8,729)
OTHER INCOME (EXPENSE), NET:
Interest income (expense), net	122	(1)
Other income (expense)	(24)
Total other income (expense), net	98	(1)
Net loss	(12,369)	(8,730)
Net loss attributable to common stockholders—basic	(12,369)	(8,730)
Net loss attributable to common stockholders— diluted	$ (12,369)	$ (8,730)
Net loss per share attributable to common stockholders—basic and diluted	$ (0.59)	$ (1.58)
Weighted-average common stock outstanding—basic and diluted	20,840,658	5,513,531