Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2014

Stock-Based Compensation

Schedule of allocation of stock-based compensation expense included in the consolidated statements of operations

	Three Months Ended March 31,
(In thousands)	2014		2013
Research and development	$	5,439	$	3,797
Selling, general and administrative	8,096		2,298
Total stock-based compensation expense	$	13,535	$	6,095

Schedule of weighted-average assumptions used to estimate the fair value of stock options granted

	Three Months Ended March 31,
	2014			2013
Employee stock options
Risk-free interest rate	1.78-1.95		%	1.01%-1.14		%
Expected term (in years)	6			6
Volatility	60		%	58		%
Dividend yield	—		%	—		%
Weighted-average estimated fair value of stock options granted	$	21.29		$	12.32