Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating expenses:
Research and development	$ 24,983	$ 2,624
In process research and development	1,000	20,898
General and administrative	8,034	2,604
Total operating expenses	34,017	26,126
Loss from operations	(34,017)	(26,126)
Other income (expenses)
Interest income	1,049	89
Interest expense	(19)
Other income	376
Total other income, net	1,406	89
Net loss	(32,611)	(26,037)
Other comprehensive income:
Unrealized gain on marketable securities, net of tax	140
Other comprehensive loss	140
Comprehensive loss	$ (32,471)	$ (26,037)
Net loss per share, basic and diluted	$ (0.90)	$ (4.49)
Weighted average common shares outstanding, basic and diluted	36,317,230	5,797,693