Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Summary of Share-Based Compensation Expense

The following table summarizes share-based compensation expense for the periods presented (in thousands):



	Year Ended December 31,
	2014		2013		2012
Research and development⁽¹⁾	$	2,270	$	980	$	6,093
General and administrative	3,327		2,148		5
Total direct expense	$	5,597	$	3,128	$	6,098
General and administrative — allocated	—		—		1,445
	$	5,597	$	3,128	$	7,543

_________________


⁽¹⁾	Includes $108,000 and $320,000 for the year ended December 31, 2014 and 2013, respectively, of share-based compensation expense related to options granted to a consultant.

The following table summarizes share-based compensation expense by type of award (in thousands):



	Year Ended December 31,
	2014		2013		2012
Stock options	$	5,597	$	3,128	$	2,621
Restricted stock units	—		—		3,477
Total direct	$	5,597	$	3,128	$	6,098
Share-based compensation expense-allocated	—		—		1,445
	$	5,597	$	3,128	7,543

Amended and Restated 2012 Long Term Incentive Plan [Member]

Summary of Company's Share Option Activity

The following table summarizes the Company’s share option activity during the year ended December 31, 2014:



	Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2013	1,973,500		$	7.50	9.17	$	37,528
Granted	720,500		28.02
Exercised	(69,244	)	7.23
Canceled	(12,676	)	15.97
Outstanding at December 31, 2014	2,612,080		$	13.13	8.45	$	25,298
Vested and expected to vest at December 31, 2014	2,535,376		$	13.00	8.44	$	24,788
Vested at December 31, 2014	1,000,307		$	7.35	8.15	$	13,448

Summary of stock activity by exercise price

The following table summarizes information about the Company's share options outstanding as of December 31, 2014:



				Options Outstanding				Options Exercisable
Range of Exercise Prices				Number of Options	Weighted - Average Remaining Contractual Life (Years)	Weighted Average Exercise Price		Number of Options	Weighted Average Exercise Price
$	6.03	$	6.03	450,937	8.06	$	6.03	216,562	$	6.03
6.41		6.41		807,381	8.08	6.41		465,271	6.41
6.65		6.65		50,000	8.21	6.65		50,000	6.65
6.73		6.73		366,000	8.25	6.73		170,478	6.73
8.21		22.14		336,062	8.89	17.51		89,246	15.34
22.16		23.11		37,500	9.74	22.86		—	—
24.26		24.26		30,000	8.84	24.26		8,750	24.26
29.52		29.52		25,000	9.09	29.52		—	—
29.81		29.81		479,200	9.09	29.81		—	—
37.02		37.02		30,000	9.25	37.02		—	—
$	6.03	$	37.02	2,612,080	8.45	$	13.13	1,000,307	$	7.35

Fair Value of Options Granted

The fair value of the options granted to employees and non-employee directors during the years ended December 31, 2014 and 2013 is estimated as of the grant date using the Black-Scholes option-pricing model assuming the weighted-average assumptions listed in the following table:



	Year Ended December 31,
	2014	2013
Expected volatility	84.4%	84.0%
Risk-free interest rate	1.8%	1.2%
Expected dividend yield	—%	—%
Expected life (in years)	6.0	6.0
Weighted average grant date fair value	$19.97	$5.22

Elan [Member]

Fair Value of Options Granted

The fair value of options granted during the year ended December 31, 2012 was estimated using the binomial option-pricing model with the following weighted-average assumptions:



	Year Ended December 31,
	2012
Expected volatility	60.1		%
Risk-free interest rate	0.9		%
Expected dividend yield	—		%
Expected life ⁽¹⁾	4.9 - 6.8
Weighted average fair value	$	6.66


⁽¹⁾	The expected life of options granted, as derived from the output of the binomial model, ranged from 4.9 to 6.8 years in 2012. The contractual life of the options, which is not more than 10 years from the date of grant, was used as an input into the binomial model.