Net Loss Per Share Attributable to Common Stockholders (Tables)

6 Months Ended

Jun. 30, 2016

Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share

The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented:

	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
Series A convertible preferred stock		286,486		2,172,520		1,229,503		2,172,520
Series B convertible preferred stock		659,337		4,933,719		2,829,657		3,079,709
Unvested restricted common stock		106,055		166,956		111,345		173,234
Options to purchase common stock		1,031,128		554,138		843,975		328,545