Quarterly Results (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

The following table is in thousands, except per share amounts:

	Quarters Ended
	March 31,			June 30,			September 30,			December 31,
	2017			2017			2017			2017
Consolidated Statement of operations data:
Revenue
Contract revenue	$	—		$	—		$	—		$	40,000
Total revenue		—			—			—			40,000
Operating expenses
Research and development		22,004			28,618			42,673			1,317
General and administrative		7,656			7,572			7,072			7,569
Total operating expenses		29,660			36,190			49,745			8,886
Income (loss) from operations		(29,660	)		(36,190	)		(49,745	)		31,114
Interest income		199			242			220			186
Other income (expense), net		(261	)		(521	)		(262	)		(547	)
Net income (loss) before provision for income taxes		(29,722	)		(36,469	)		(49,787	)		30,753
Provision for (benefit from) income taxes		—			128			—			(375	)
Net income (loss)	$	(29,722	)	$	(36,597	)	$	(49,787	)	$	31,128
Net income (loss) per share- basic	$	(0.85	)	$	(1.04	)	$	(1.40	)	$	0.87
Weighted-average common shares used to compute      basic net income (loss) per share		35,004			35,316			35,680			35,872
Net loss per share- diluted	$	(0.85	)	$	(1.04	)	$	(1.40	)	$	0.87
Weighted-average common shares used to compute      diluted net income (loss) per share		35,004			35,316			35,680			35,901
	Quarters Ended
	March 31,			June 30,			September 30,			December 31,
	2016			2016			2016			2016
Consolidated Statement of operations data:
Operating expenses
Research and development	$	18,192		$	16,397		$	20,664		$	16,731
General and administrative		5,915			5,909			6,752			5,760
Total operating expenses		24,107			22,306			27,416			22,491
Loss from operations		(24,107	)		(22,306	)		(27,416	)		(22,491	)
Interest income		105			129			120			160
Other income (expense), net		(230	)		59			(39	)		446
Net loss before provision for income taxes		(24,232	)		(22,118	)		(27,335	)		(21,885	)
Provision for income taxes		—			—			—			247
Net loss attributable to common stockholders	$	(24,232	)	$	(22,118	)	$	(27,335	)	$	(22,132	)
Net loss per basic and diluted share attributable to      common stockholders	$	(0.82	)	$	(0.75	)	$	(0.92	)	$	(0.64	)
Weighted-average common shares used to compute      basic and diluted net loss per share		29,422			29,489			29,574			34,609