Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation Expense

Our stock-based compensation expense for the three and nine months ended September 30 was as follows:

	Three months ended						Nine months ended
	September 30,						September 30,
	2016			2015			2016			2015
Research and development expense	$	—		$	781,791		$	(237,780	)	$	2,063,499
General and administrative expense		(189,140	)		644,451			980,954			2,023,211
Total stock-based compensation	$	(189,140	)	$	1,426,242		$	743,174		$	4,086,710
Effect on basic and diluted net loss per share	$	0.01		$	(0.16	)	$	(0.06	)	$	(0.54	)

Stock Option Activity

A summary of our stock option activity for the three months ended September 30, 2016 is as follows:

	Number of options			Weighted-average exercise price ($) per share
Outstanding options at June 30, 2016		27,831			135.64
Granted		—			—
Exercised		—			—
Cancelled		(7,740	)		87.60
Outstanding options at September 30, 2016		20,091			154.15

Summary of Changes in Unvested Options

A summary of changes in unvested options for the three months ended September 30, 2016 is as follows:

	Number of options		Weighted-average exercise price ($) per share		Weighted-average grant date fair value ($) per option
Unvested options at June 30, 2016		1,250		8.52		5.53
Granted		—		—		—
Vested		—		—		—
Cancelled		—		—		—
Unvested options at September 30, 2016		1,250		8.52		5.53

Summary of Changes in Restricted Stock Units

A summary of changes in our restricted stock units for the three months ended September 30, 2016 is as follows:

	Number of RSUs			Weighted Average Grant Date Fair Value ($)
Outstanding at June 30, 2016		333,930			10.18
Granted		—			—
Vested and exercised		(194,620	)		10.05
Cancelled		(5,834	)		22.08
Outstanding at September 30, 2016		133,476			9.87