Net Loss per Share Attributable to Common Stockholders (Tables)

6 Months Ended

Jun. 30, 2015

Common Equivalent Shares Excluded from Computation of Diluted Net Loss

The following common equivalent shares were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive:

	Three Months Ended June 30,				Six Months Ended June 30,
	2015		2014		2015		2014
Stock options to purchase common stock		4,796,918		4,226,170		4,796,918		4,226,170
Common stock warrants		1,500		13,873		1,500		13,873
Restricted stock units		173,575		—		173,575		—
Performance stock units		165,000		—		165,000		—