Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Significant Components Deferred Tax Assets

Deferred tax assets are as follows (in thousands):

	December 31,
	2020			2019
Deferred tax assets:
Net operating loss carryforwards	$	84,827		$	81,406
Research and development credits		24,179			24,011
Deferred royalty obligation		36,265			30,460
Share-based compensation expense		2,497			9,581
Depreciation and amortization expense		1,044			-
Lease liability		136			7,127
Other		436			1,263
Total gross deferred tax assets		149,384			153,848
Deferred tax liabilities:
Depreciation and amortization		-			(1,612	)
Right-of-use lease asset		(136	)		(3,775	)
Valuation allowance		(149,248	)		(148,461	)
Net deferred tax assets	$	-		$	-

Schedule of Provision for Income Taxes

The difference between income taxes computed using the U.S. federal income effective tax rate and the provision for income taxes is as follows (in thousands):

	Year Ended December 31,
	2020			2019
Federal statutory rate	$	(8,278	)	$	(24,467	)
State tax benefit		(1,740	)		(3,825	)
Change in valuation allowance		787			102,583
Share-based compensation expense		9,072			7,532
State rate true-up		291			2,513
Establishment of NOLs and credits, post-Section 382 ownership change		-			(81,368	)
Research and development credits		(173	)		(2,599	)
Foreign rate differential		-			(62	)
Other permanent differences		41			(307	)
Provision for income taxes	$	-		$	-