Note 13 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	Years Ended December 31,
	2021			2020
Domestic	$	(159,632	)	$	(176,613	)
Foreign		(22,177	)		(6,201	)
Loss before provision for income taxes	$	(181,809	)	$	(182,814	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	2021			2020			2019
Income tax benefit at federal statutory rate (21% for 2021, 2020 and 2019)	$	(38,175	)	$	(38,391	)	$	(22,868	)
State and local income taxes net of federal tax benefit		(2,288	)		(2,544	)		(1,591	)
Permanent items		(1,343	)		774			691
Rate change		−			(82	)		625
Expiration of attribute carryforwards		(1,057	)		3,774			3,976
Research and development tax credits		(5,994	)		(4,080	)		(4,938	)
Foreign rate differential		1,940			542			-
Other		1,216			1,456			281
Change in valuation allowance		47,954			38,551			23,824
Income tax expense	$	2,253		$	−		$	−

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	2021		2020
Balance at January 1,	$	8,230	$	7,210
Additions to current period tax positions		1,499		1,020
Balance at December 31,	$	9,729	$	8,230

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	2021			2020
Deferred tax assets:
Net federal and state operating losses	$	113,649		$	159,939
Research and development credits		71,197			66,331
Royalty income		106,007			28,034
Stock-based compensation		14,512			10,732
Capitalized R&D		8,997			−
Leasing obligations		1,836			1,135
Other		4,809			5,563
Total deferred tax assets		321,007			271,734
Deferred tax liabilities:
Fixed assets		(607	)		(124	)
Right of use asset		(1,527	)		(854	)
Total deferred tax liabilities		(2,134	)		(978	)
Valuation allowance		(318,714	)		(270,756	)
Net deferred tax assets	$	159		$	−