Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Taxes

Schedule of significant components of the Company's deferred tax assets

	December 31,
(In thousands)	2014			2013
Deferred tax assets:
Net operating loss carryforwards	$	386,000		$	480,000
Deferred revenues		2,000			5,000
Capitalized research and development expenditures		—			5,000
Research and development tax credit carryforwards		53,000			44,000
Other		18,000			28,000
Total deferred tax assets		459,000			562,000
Valuation allowance		(459,000	)		(562,000	)
Net deferred tax assets	$	—		$	—

Schedule of the differences between the U.S. federal statutory income tax rate to the Company's effective tax rate

	Year Ended December 31,
	2014			2013			2012
U.S. federal statutory income tax rate		35.00	%		34.00	%		34.00	%
Federal and state research credits		12.66			3.63			(4.21	)
Non-deductible executive compensation		(0.16	)		(0.07	)		(13.24	)
Stock-based compensation		(1.11	)		0.28			(1.36	)
Expiration of net operating loss		—			—			(1.81	)
Effect of Spin-Off Transaction		(203.2	)		—			—
Other		(4.04	)		(2.51	)		(2.09	)
Change in valuation allowance		160.85			(35.33	)		(11.29	)
Effective tax rate		(0.00	)%		(0.00	)%		(0.00	)%

Reconciliation of gross unrecognized tax benefits

        A reconciliation of the beginning and ending balances of the total amounts of unrecognized tax benefits are as follows (in thousands):

Unrecognized tax benefits as of December 31, 2011	$	46,900
Gross decrease for tax positions for prior years		—
Gross increase in tax positions for current year		5,600
Unrecognized tax benefits as of December 31, 2012		52,500
Gross decrease for tax positions for prior years		(565	)
Gross increase in tax positions for current year		5,485
Unrecognized tax benefits as of December 31, 2013		57,420
Gross decrease for tax positions for prior years		(42,650	)
Gross increase in tax positions for current year		689
Unrecognized tax benefits as of December 31, 2014	$	15,459