Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Collaboration and license revenue		$ 6,639		$ 11,970
Operating expenses:
Research and development	$ 27,708	17,218	$ 53,898	33,836
Selling, general and administrative	13,856	8,912	27,407	16,225
Total operating expenses	41,564	26,130	81,305	50,061
Loss from operations	(41,564)	(19,491)	(81,305)	(38,091)
Interest and other income, net	3,172	1,078	5,443	1,858
Loss before income taxes	(38,392)	(18,413)	(75,862)	(36,233)
Income tax benefit	(218)	0	(218)	0
Net loss	(38,174)	(18,413)	(75,644)	(36,233)
Other comprehensive income (loss), net of tax effect of $219, $0, $219, $0, respectively	201	70	564	(67)
Comprehensive loss	$ (37,973)	$ (18,343)	$ (75,080)	$ (36,300)
Net loss per share, basic and diluted	$ (0.83)	$ (0.49)	$ (1.75)	$ (0.99)
Weighted average number of shares used to compute net loss per share, basic and diluted	46,065,901	37,440,024	43,301,417	36,620,747

Interest and other income (expense), net.

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