Quarterly Results (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

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,
	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	$	(24,232	)	$	(22,118	)	$	(27,335	)	$	(22,132	)
Net loss per share- basic and diluted	$	(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
	Quarters Ended
	March 31,			June 30,			September 30,			December 31,
	2015			2015			2015			2015
Consolidated Statement of operations data:
Operating expenses
Research and development	$	17,100		$	11,940		$	15,400		$	15,586
General and administrative		5,181			7,556			5,124			4,622
Total operating expenses		22,281			19,496			20,524			20,208
Loss from operations		(22,281	)		(19,496	)		(20,524	)		(20,208	)
Interest income		49			65			54			51
Other income (expense), net		226			(236	)		91			32
Net loss and comprehensive loss		(22,006	)		(19,667	)		(20,379	)		(20,125	)
Net loss attributable to common stockholders	$	(22,006	)	$	(19,667	)	$	(20,379	)	$	(20,125	)
Net loss per basic and diluted share attributable to      common stockholders	$	(0.79	)	$	(0.67	)	$	(0.69	)	$	(0.69	)
Weighted-average common shares used to compute      basic and diluted net loss per share		27,810			29,293			29,354			29,379