CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating expenses:
Research and development	$ 49,381	$ 31,423
General and administrative	23,526	6,352
Total operating expenses	72,907	37,775
Loss from operations	(72,907)	(37,775)
Other income (expense), net	813	1,267
Interest expense	(2,020)	(1,389)
Net loss	(74,114)	(37,897)
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale investments, net of tax	(232)	302
Total comprehensive loss	$ (74,346)	$ (37,595)
Net loss per share, basic and diluted (in USD per share)	$ (1.49)	$ (0.90)
Weighted-average number of shares outstanding, basic and diluted (in shares)	49,841,407	42,268,062