Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Assumptions Used to Calculate Fair Value of Options Granted to Employees

The fair value of stock options granted to employees during the three months ended March 31, 2017 and 2016 was estimated at the date of grant using the following assumptions:

	Three Months Ended March 31,
	2017	2016
Risk-free interest rate	2.10%	1.3-1.5%
Expected dividend yield	0%	0%
Expected term	5.8 years	5.8 years
Expected volatility	67-68%	67-68%

Schedule of Recognized Stock-Based Compensation Expense

The Company recognized stock-based compensation expense during the three months ended March 31, 2017 and 2016 as follows:

	Three Months Ended March 31,
(in thousands)	2017		2016
Employee awards:
Research and development expense	$	468	$	1,525
Selling, general and administrative expense		328		985
Total stock-based compensation expense	$	796	$	2,510

Summary of Stock Option Activity

The following table summarizes stock option activity during the three months ended March 31, 2017:

						Weighted-Average Remaining		Aggregate
(in thousands, except per share amounts)	Options			Weighted-Average Exercise Price		Contractual Term (in years)		Intrinsic Value
Outstanding at December 31, 2016		19,024		$	5.77		5.97	$	7,564
Granted		3		$	4.00
Exercised		(1,714	)	$	2.27
Forfeited		(790	)	$	6.49
Outstanding at March 31, 2017		16,523		$	6.10		2.34	$	1,989
Vested and expected to vest at March 31, 2017		16,367		$	6.10		2.34	$	1,989
Exercisable at March 31, 2017		13,827		$	5.96		2.25	$	1,989