Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

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

Stock-Based Compensation Expense for Options Granted, Restricted Stock and Stock Purchase Rights as Reflected in Statement of Operations

Stock-based compensation expense for options and restricted stock awards (“RSAs”) is reflected in the condensed consolidated statements of operations and comprehensive loss as follows:

	THREE MONTHS ENDED   JUNE 30,				SIX MONTHS ENDED   JUNE 30,
(in thousands)	2017		2016		2017		2016
Research and development	$	1,414	$	814	$	2,478	$	1,526
Selling, general and administrative	5,251		3,067		9,037		5,889
Total	$	6,665	$	3,881	$	11,515	$	7,415

Schedule of Stock Options Activity

The following table summarizes the stock option activity under the Plans:

	NUMBER OF SHARES		WEIGHTED AVERAGE EXERCISE PRICE		WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)	AGGREGATE INTRINSIC VALUE (000’s)
Options outstanding at December 31, 2016	5,255,930		$	14.34
Granted	988,459		44.63
Exercised	(198,735	)	10.93
Canceled	(17,571	)	34.34
Options outstanding at June 30, 2017	6,028,083		$	19.36	7.4	$	200,150
Options exercisable at June 30, 2017	3,692,130		$	11.85	6.5	$	150,268

Restricted Stock and Restricted Stock Units Activity

The following table summarizes the RSA activity under the Plans:

	NUMBER OF SHARES		WEIGHTED AVERAGE FAIR VALUE PER SHARE
Nonvested RSAs at December 31, 2016	164,194		$	19.87
Granted	246,393		44.56
Vested	(54,591	)	20.47
Canceled	(2,336	)	43.90
Nonvested RSAs at June 30, 2017	353,660		$	36.82