Net Loss per share (Tables)

12 Months Ended

Dec. 31, 2014

Net Loss per share

Summary of potentially dilutive securities outstanding excluded from the computation of diluted weighted-average shares outstanding

	As of December 31,
	2014		2013
Convertible preferred stock		—		27,248,746
Settlement of loan agreement		248,093		13,002,222
Options to purchase common stock		1,652,882		458,871
Warrants to purchase preferred stock		—		5,267,726
Warrants to purchase common stock		93,040		—
Nonvested restricted stock		13,259		—