Note 8 - Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Notes Tables

Schedule of Share-based Compensation, Expense [Table Text Block]

	Three months ended
	March 31,
	2024		2023
Research and development	$	115	$	139
Selling, general and administrative		89		139
Total share-based compensation	$	204	$	278

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

	Number of shares			Weighted average exercise price		Weighted average remaining contractual term (years)		Aggregate intrinsic value (in thousands)
Balance, December 31, 2023		2,486,767		$	3.51		6.8	$	43
Stock options forfeited		(47,657	)		2.26
Balance, March 31, 2024		2,439,110		$	3.54		6.6	$	1
Exercisable, March 31, 2024		1,601,718		$	4.49		5.6	$	—