Loss Per Share of Common Stock (Tables)

6 Months Ended

Jun. 30, 2016

Loss Per Share of Common Stock

Schedule of computation of diluted net loss per share

	Three Months Ended June 30,				Six Months Ended June 30,
	2015		2016		2015		2016
Numerator:
Net loss	$	(11,873,047)	$	(6,746,601)	$	(24,556,029)	$	(17,811,871)
Less: income from change in fair value of warrant liability		(125,557)		—		(158,180)		—
Numerator for diluted net loss per common share	$	(11,998,604)	$	(6,746,601)	$	(24,714,209)	$	(17,811,871)
Denominator:
Basic weighted average common shares outstanding		23,332,096		24,769,083		23,074,550		24,769,083
Dilutive common shares from assumed warrant exercises		38,239		—		41,703		—
Diluted weighted average shares of common stock outstanding		23,370,335		24,769,083		23,116,253		24,769,083
Diluted net loss per share of common stock	$	(0.51)	$	(0.27)	$	(1.07)	$	(0.72)

Schedule of potentially dilutive securities outstanding that have been excluded from the computation of diluted weighted average shares outstanding, as they would be antidilutive

	Three Months Ended June 30,		Six Months Ended June 30,
	2015	2016	2015	2016
Warrants	23,747	54,776	23,747	54,776
Stock options	4,027,517	3,448,930	3,654,220	3,527,711
Common shares issuable upon conversion of the 8% Notes	8,058,271	8,058,271	8,058,271	8,058,271
	12,109,535	11,561,977	11,736,238	11,640,758