Selected Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Summary of Unaudited Quarterly Financial Data

The following table summarizes the unaudited quarterly financial data for the last two fiscal years (in thousands).

Year Ended December 31, 2017	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
License and other revenue	$	68		$	3		$	—		$	1,534
Total operating expenses	$	30,347		$	29,755		$	31,055		$	40,986
Loss from operations	$	(30,279	)	$	(29,752	)	$	(31,055	)	$	(39,452	)
Total other income (expense)	$	385		$	383		$	428		$	421
Net loss	$	(29,917	)	$	(29,387	)	$	(30,640	)	$	(39,040	)
Net loss per share, basic and diluted	$	(0.71	)	$	(0.64	)	$	(0.65	)	$	(0.80	)
Year Ended December 31, 2016	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
Contract and grant revenue	$	—		$	59		$	48		$	47
Total operating expenses	$	27,349		$	30,535		$	25,790		$	27,212
Loss from operations	$	(27,349	)	$	(30,476	)	$	(25,742	)	$	(27,165	)
Total other income (expense)	$	290		$	318		$	317		$	369
Net loss	$	(27,059	)	$	(30,158	)	$	(25,425	)	$	(26,935	)
Net loss per share, basic and diluted	$	(0.75	)	$	(0.84	)	$	(0.69	)	$	(0.65	)