Note 8 - Share-based Compensation

3 Months Ended

Mar. 31, 2024

Notes to Financial Statements

Share-Based Payment Arrangement [Text Block]

(8) Share-Based Compensation

The share-based compensation expense is recorded in research and development, and selling, general and administrative expenses based on the employee's or non-employee’s respective function. No share-based compensation was capitalized during the periods presented. Share-based compensation expense for the three months ended March 31, 2024 and 2023 was recorded as follows (in thousands):

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

The following table summarizes the activity of stock options and related information:

	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	$	—

Unrecognized share-based compensation for employee and nonemployee options granted through March 31, 2024 is approximately $1.2 million to be recognized over a remaining weighted average service period of 2.1 years.

Share-Based Compensation (RSUs)

There were no RSUs outstanding and hence there is no unrecognized share-based compensation at March 31, 2024 and December 31, 2023.