Employee and Consultant Equity-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2016

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

Stock Option Activity

The following table summarizes option activity under all plans during the six-month period ending June 30, 2016:

Stock Option Activity
	Number of Shares		Weighted Average Exercise Price per Share
Options outstanding January 1, 2016	6,167,170		6.91
Granted	899,600		13.09
Forfeited	(119,706	)	20.06
Exercised	(27,233	)	3.49
Expired	(1,789	)	13.49
Options Outstanding June 30, 2016	6,918,042		7.49

Black-Scholes Assumptions for Options Granted

The table below summarizes the resulting weighted average inputs used to calculate the estimated fair value of options awarded for during the periods shown below:

Black-Scholes Assumptions for Options Granted
	Three Months Ended
	June 30, 2016	June 30, 2015
Expected term (in years)	6.2	6.4
Volatility	85%	92%
Expected dividends	—	—
Risk free interest rates	1.45%	1.73%
Weighted average fair value	$9.66	$17.55

Stock Option Supplemental Information

The following table shows summary information for outstanding options, options that are exercisable (vested) and outstanding options that are either vested or expected to vest as of June 30, 2016:

Stock Option Supplemental Information
	Options Outstanding		Options Exercisable		Options Vested and Expected to Vest
Number of options	6,918,042		4,268,778		6,715,032
Weighted average remaining contractual term (in years)	7.06		6.41		7.00
Weighted average exercise price	$	7.49	$	5.01	$	7.28
Weighted average fair value	$	5.80	$	3.77	$	5.63
Aggregate intrinsic value (in thousands)	$	37,775	$	34,813	$	38,171

Restricted Stock Unit (RSU) Activity

The following table summarizes restricted stock unit activity during the six-month period ending June 30, 2016:

Restricted Stock Unit (RSU) Activity
	Number of Shares	Weighted Average Grant Date Fair Value per Share
RSUs Outstanding January 1, 2016	40,250	20.91
Granted	—	—
Forfeited	—	—
Vested/released	—	—
RSUs outstanding June 30, 2016	40,250	20.91

Equity-Based Compensation Expenses

The expense recognized on Company’s Statements of Operations and Comprehensive Loss related to options is summarized below:

Equity-Based Compensation Expenses (in thousands)
	Three Months Ended				Six Months Ended
	6/30/2016		6/30/2015		6/30/2016		6/30/2015
Research and development	$	462	$	747	$	664	$	1,435
Sales, general and administrative	1,773		1,781		3,257		2,750
Equity-based compensation expense	$	2,235	$	2,528	$	3,921	$	4,185