Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

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):


	2019		2018
Deferred tax assets:
Federal and State net operating loss carryforward	$	293,736	$	270,177
Foreign net operating loss carryforward		13,520		12,321
Research tax credits		37,066		33,633
Non-cash stock-based compensation		13,679		10,888
Original discount interest		4,326		5,687
Other		5,957		7,987
Total deferred tax assets		368,284		340,693
Valuation allowance		(365,772)		(337,515)
Net deferred tax assets	$	2,512	$	3,178

Deferred tax liabilities:
Intangibles		(1,279)		(1,492)
Other		(1,233)		(1,686)
Total deferred tax liabilities		(2,512)		(3,178)
Net deferred tax assets	$	—	$	—

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


	2019		2018		2017
Statutory federal tax rate	(21)	%	(21)	%	(34)	%
State income taxes, net of federal benefit	(2)	%	(3)	%	(3)	%
Research and development and other tax credits	(3)	%	(3)	%	(2)	%
Other	1	%	1	%	(1)	%
Change in tax rate	3	%	5	%	70	%
Change in valuation allowance	22	%	21	%	(30)	%
Income tax provision	0	%	0	%	0	%

As of December 31, 2019, 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	$	965,284
Federal and State net operating losses (no expiration)		284,084
Foreign net operating losses (no expiration)		36,972
Research tax credits expiring through the year 2039		61,455