Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Stock-Based Compensation Expense

The following table presents stock-based compensation expense included in the Company’s consolidated statements of comprehensive income (in thousands):

	Three months ended September 30,				Nine months ended September 30,
	2016		2015		2016		2015
Cost of product revenue	$	116	$	60	$	260	$	166
Research and development		177		91		362		250
Selling, general and administrative		989		830		2,719		2,252
Total	$	1,282	$	981	$	3,341	$	2,668

Summary of Option Activity

Information regarding option activity for the nine months ended September 30, 2016 under the Plans is summarized below:

	Options Outstanding			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)		(in thousands) Aggregate Intrinsic Value
Options outstanding at January 1, 2016		1,240,935		$	10.44
Granted		366,003			11.22
Exercised		(305,535	)		5.81
Forfeited/Cancelled		(102,730	)		8.40
Options outstanding at September 30, 2016		1,198,673		$	12.03		7.49	$	22,172
Options exercisable at September 30, 2016		432,002		$	11.28		5.43	$	8,396
Vested and expected to vest at September 30, 2016 (1)		1,115,150		$	12.26		7.42	$	20,396

(1) This represents the number of vested options as of September 30, 2016 plus the number of unvested options expected to vest as of September 30, 2016 based on the unvested outstanding options at September 30, 2016 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.