Note 9 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2025

Notes Tables

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year Ended December 31,
	2025		2024
	(000's)
Research and development	$	3,346	$	2,971
General and administrative		5,022		5,589
Total	$	8,368	$	8,560

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Options (000's)			Weighted Average Exercise Price Price Per Share		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (000's)
Outstanding at December 31, 2023		7,876		$	3.81		8.05	$	11
Granted		6,193		$	1.58		7.10	$	—
Exercised		—		$	—		—	$	—
Forfeited/cancelled		(7	)	$	3.04		—	$	—
Outstanding at December 31, 2024		14,062		$	2.83		6.23	$	579
Granted		4,777		$	3.63		8.76	$	2
Exercised		(545	)	$	2.34		—	$	1,214
Forfeited/cancelled		(1,942	)	$	2.40		—	$	2,341
Outstanding at December 31, 2025		16,352		$	3.13		6.69	$	36,614
Vested at December 31, 2025		9,513		$	3.38		5.24	$	18,932

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	2025			2024
Expected term (in years)		6.0			6.0
Risk-free rate		4.26	%		3.92	%
Expected volatility		86	%		81	%

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

	Shares (000's)			Weighted Average Price Per Share		Weighted Average Fair Value (000's)
Unvested, December 31, 2023		1,500		$	3.83	$	5,745
Granted		2,791			1.89		5,275
Vested		(525	)		3.87		(2,032	)
Forfeited or canceled		—			—		—
Unvested, December 31, 2024		3,766		$	2.41	$	9,076
Granted		—		$	—	$	—
Vested		(1,073	)		2.59		(2,779	)
Forfeited or canceled		(1,665	)		2.34		(3,896	)
Unvested, December 31, 2025		1,028		$	2.33	$	2,395