Net Loss per Share Attributable to Common Stockholders (Tables)

6 Months Ended

Jun. 30, 2014

Outstanding Shares of Common Equivalent Shares Excluded from Computation of Diluted Net Loss

The following outstanding shares of 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,
	2014		2013		2014		2013
Stock options to purchase common stock		4,226,170		3,787,915		4,226,170		3,787,915
Common stock warrants		13,873		82,575		13,873		82,575