Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

The Company’s loss from operations before income tax expense by jurisdiction for the years ended December 31 are as follows (in thousands):

Deferred tax assets (liabilities) consist of the following at December 31 (in thousands):

	2017		2016
Deferred tax assets:
Federal and State net operating loss carryforward	$	240,550	$	286,619
Foreign net operating loss carryforward		11,577		9,011
Research tax credits		27,571		23,260
Deferred revenue		668		10,121
Original discount interest		7,167		12,445
Other		16,496		17,981
Total deferred tax assets		304,029		359,437
Valuation allowance		(299,862)		(354,530)
Net deferred tax assets	$	4,167	$	4,907

Deferred tax liabilities:
Intangibles		(1,789)		(2,090)
Other		(2,378)		(2,817)
Total deferred tax liabilities		(4,167)		(4,907)
Net deferred tax assets	$	—	$	—

The differences between the U.S. federal statutory tax rate and the Company’s effective tax rate are as follows:

	2017			2016			2015
Statutory federal tax rate		(34)	%		(34)	%		(34)	%
State income taxes, net of federal benefit		(3)	%		(3)	%		(3)	%
Research and development and other tax credits		(2)	%		(2)	%		(3)	%
Release of FIN 48 liability		0	%		0	%		(2)	%
Other		(1)	%		2	%		1	%
Change in tax rate		70	%		0	%		0	%
Change in valuation allowance		(30)	%		37	%		41	%
Income tax provision		0	%		0	%		0	%

As of December 31, 2017, the Company had net operating losses and research tax credits available as follows (in thousands):

	Amount
Federal and State net operating losses expiring through the year 2037	$	974,463
Foreign net operating losses (no expiration)		52,621
Research tax credits expiring through the year 2037		27,477