STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2015

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

Summary of Stock Awards Granted

The following table summarizes the Company’s stock awards granted for each of the periods indicated:

	For the Three Months Ended March 31,
	2015				2014
	Grants		Weighted Average Grant Date Fair Value		Grants		Weighted Average Grant Date Fair Value
Stock options*		1,607,544	$	10.35		1,185,265	$	19.41
Restricted stock awards		6,000	$	13.90		6,000	$	29.03

* Stock options granted for both periods presented in the table have only service-based criteria and vest over four years.

Summary of Stock-Based Compensation Expense by Function Included within Condensed Consolidated Statement of Operations and Comprehensive Loss

The following table summarizes share-based compensation expense by function included within the unaudited condensed consolidated statements of operations and comprehensive loss:

	For the Three Months Ended March 31,
	2015		2014
	(in thousands)
Research and development	$	2,446	$	1,873
General and administrative		11,710		2,469
Total	$	14,156	$	4,342

Summary of Stock-Based Compensation Expense by Grant Type Included within Condensed Consolidated Statement of Operations and Comprehensive Loss

The following table summarizes share-based compensation expense by grant type included within the unaudited condensed consolidated statements of operations and comprehensive loss:

	For the Three Months Ended March 31,
	2015		2014
	(in thousands)
Stock options	$	13,551	$	3,911
Restricted stock awards		42		64
Restricted stock units		—		(4	)
Stock appreciation rights		147		147
Employee stock purchase plan		416		224
Total	$	14,156	$	4,342