Note 8 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2025

Notes Tables

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

	Three Months Ended March 31,
	2025		2024
	(000’s)
Research and development	$	807	$	924
General and administrative		1,707		1,079
Total	$	2,514	$	2,003

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

			Weighted		Weighted
	Number of		Average		Average		Aggregate
	Unvested		Exercise		Remaining		Intrinsic
	Options		Price		Contractual		Value
	(000's)		Per Share		Term (in years)		($000's)
Outstanding at December 31, 2024		14,062	$	2.83		6.23	$	579
Granted		4,482	$	3.61		9.86		2
Exercised		—	$	—		—		—
Forfeited/canceled		—	$	—		—		—
Outstanding at March 31, 2025		18,544	$	3.02		6.92	$	2,146
Vested at March 31, 2025		7,379	$	3.55		5.22	$	374

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

	Three Months Ended March 31,
	2025			2024
Expected term (in years)		6.0			6.0
Risk-free rate		4.28	%		4.04	%
Expected volatility		86	%		80	%
Expected dividend yield		—			—

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, 2024		3,766		$	2.41	$	9,076
Granted		—			—		—
Vested		(823	)		2.48		(2,042	)
Forfeited or canceled		—			—		—
Unvested, March 31, 2025		2,943		$	2.39	$	7,034