Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating expenses:
Research and development	$ 143,403	$ 55,283	$ 891
In process research and development	3,600	49,659	5,500
General and administrative	39,136	44,051	262
Total operating expenses	186,139	148,993	6,653
Loss from operations	(186,139)	(148,993)	(6,653)
Other income (expense), net	5,832	2,024	(118)
Net loss	(180,307)	(146,969)	(6,771)
Other comprehensive income:
Foreign currency translation, net of tax	(12)
Unrealized gain (loss) on marketable securities, net of tax	331	(61)
Other comprehensive income (loss)	319	(61)
Comprehensive loss	$ (179,988)	$ (147,030)	$ (6,771)
Net loss per share, basic and diluted	$ (3.29)	$ (22.59)	$ (0.74)
Weighted average common shares outstanding, basic and diluted	54,740,170	6,504,871	9,160,888