Net loss per share

9 Months Ended

Sep. 30, 2014

Earnings Per Share [Abstract]

Net loss per share

10. Net loss per share

The following common stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:

	Three months ended September 30,			Nine months ended September 30,
		2014	2013		2014	2013
Warrants		338	440		338	440
Outstanding stock options		4,042	3,977		4,042	3,977
Unvested restricted stock		7	89		7	89
Restricted stock units		184	—		184	—
ESPP shares		2	—		2	—
Acquisition holdback (Note 7)		94	—		94	—
		4,667	4,506		4,667	4,506