Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
OPERATING EXPENSES:
Research and development	$ 7,453	$ 2,726	$ 18,582	$ 6,111
General and administrative	3,294	598	9,331	1,418
Total operating expenses	10,747	3,324	27,913	7,529
LOSS FROM OPERATIONS	(10,747)	(3,324)	(27,913)	(7,529)
OTHER INCOME (EXPENSE), NET:
Interest income (expense), net	34	(584)	33	(1,400)
Other expense		(373)		(873)
Total other income (expense), net	34	(957)	33	(2,273)
Net loss	(10,713)	(4,281)	(27,880)	(9,802)
Net loss attributable to common stockholders—basic	(10,713)	(4,281)	(27,880)	(9,802)
Net loss attributable to common stockholders— diluted	$ (10,713)	$ (4,281)	$ (27,880)	$ (9,802)
Net loss per share attributable to common stockholders—basic and diluted	$ (0.63)	$ (0.78)	$ (1.98)	$ (1.79)
Weighted-average common stock outstanding—basic and diluted	17,095,870	5,497,871	14,085,579	5,473,414