Note 12 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2024

Notes Tables

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	Year Ended December 31,
	2024		2023
Current:
Federal	$	—	$	—
State		3		3
Foreign		257		258
Total Current		260		261
Deferred:
Federal		—		—
State		—		—
Foreign		—		—
Total Deferred		—		—
Provision for income taxes	$	260	$	261

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

	December 31, 2024			December 31, 2023
Deferred tax assets:
Net operating loss carryforwards	$	48,154		$	47,720
Research and development tax credits		12,949			10,187
Capitalized research and development		27,892			21,676
Sale of future royalties		1,179			1,623
Lease liability		3,682			4,206
Accruals, reserves and other		6,676			4,827
Total deferred tax assets		100,532			90,239
Valuation allowance		(94,119	)		(82,500	)
Deferred tax assets net of valuation allowance		6,413			7,739
Deferred tax liabilities:
Intangible assets		(1,999	)		(2,308	)
Right-of-use assets		(4,309	)		(5,216	)
Depreciation on property and equipment		(105	)		(215	)
Total deferred tax liabilities		(6,413	)		(7,739	)
Net deferred tax assets	$	—		$	—

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

	Year Ended December 31,
	2024			2023
U.S. federal taxes at statutory rate		21.0	%		21.0	%
State taxes (net of federal benefit)		0.1			0.1
Foreign rate differential		(0.7	)		(1.1	)
Permanently non-deductible items		(0.1	)		—
Tax credits		4.2			2.7
Change in valuation allowance		(17.4	)		(19.7	)
Prior year true-up		(5.5	)		(0.1	)
Stock-based compensation		(2.0	)		(3.2	)
Provision for income taxes		(0.4	)%		(0.3	)%

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

	Year Ended December 31,
	2024			2023
Beginning Balance	$	6,566		$	4,945
Additions based on tax positions related to the current year		1,977			1,621
Decreases related to prior years’ tax positions		(6	)		—
Ending Balance	$	8,537		$	6,566