Note 20 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2024

Notes Tables

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

	Year ended December 31,
	2024			2023
U.S. federal tax benefit at statutory rate		21	%		21	%
Non-deductible expenses and other		(0.8	)%		(0.4	)%
Stock-based compensation		(6.7	)%		(4.6	)%
Research and development credits		2.2	%		2.3	%
Change in valuation allowance, net		(15.7	)%		(18.4	)%
Effective tax rate		0.0	%		(0.1	)%

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

	As of December 31,
	2024			2023
Deferred tax assets:
Net operating loss carryforwards	$	80,580		$	69,612
Research and development credit carryforward		10,719			9,941
Stock-based compensation		215			301
Property and equipment		1,090			2,364
Operating lease liabilities		1,208			4,967
Capitalized R&D expenses		12,401			14,194
Other accruals		1,715			689
Gross deferred tax assets		107,928			102,068
Valuation allowance		(107,734	)		(98,840	)
Deferred tax assets net of valuation allowance		194			3,228
Deferred tax liabilities:
Right-of-use assets		(194	)		(3,228	)
Gross deferred tax liabilities		(194	)		(3,228	)
Total deferred tax assets (liabilities), net	$	—		$	—

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

	Year ended December 31,
	2024			2023
Unrecognized tax benefits as of the beginning of the year	$	3,480		$	2,822
Decreases (increases) related to prior year tax provisions		(5	)		161
Increase related to current year tax provisions		265			497
Unrecognized tax benefits as of the end of the year	$	3,740		$	3,480