Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Selected Quarterly Financial Data (Unaudited) [Abstract]

Selected Quarterly Financial Data (Unaudited)

The following table summarizes unaudited quarterly financial data for the years ended December 31, 2016 and 2015 (in thousands, except per share data).

	2016
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter			Total
Total operating expenses	$	9,032		$	9,264		$	10,277		$	10,939		$	39,512
Loss from operations	$	(9,032	)	$	(9,264	)	$	(10,277	)	$	(10,939	)	$	(39,512	)
Net loss and comprehensive loss	$	(9,170	)	$	(9,376	)	$	(10,759	)	$	(9,516	)	$	(38,821	)
Net loss attributable to common stockholders	$	(9,170	)	$	(9,376	)	$	(10,759	)	$	(9,516	)	$	(38,821	)
Loss per share attributable to common stockholders basic and diluted	$	(0.32	)	$	(0.33	)	$	(0.37	)	$	(0.33	)	$	(1.34	)

	2015
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter			Total
Total operating expenses	$	4,182		$	4,961		$	8,485		$	8,871		$	26,499
Loss from operations	$	(4,182	)	$	(4,961	)	$	(8,485	)	$	(8,871	)	$	(26,499	)
Net loss and comprehensive loss	$	(4,468	)	$	(5,521	)	$	(10,130	)	$	(7,960	)	$	(28,079	)
Net loss attributable to common stockholders	$	(5,152	)	$	(7,267	)	$	(11,958	)	$	(8,058	)	$	(32,435	)
Loss per share attributable to common stockholders basic and diluted	$	(3.05	)	$	(4.30	)	$	(7.08	)	$	(0.30	)	$	(4.01	)