Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Share-based Compensation, Stock Options, Activity

Stock option activity for the nine months ended September 30, 2023 is represented in the following table:

			Options Outstanding
	Shares					Weighted- Average
	Available		Number of			Exercise
	for Grant		Shares			Price
Balances at December 31, 2022	396,014		2,111,379		$	7.36
Options granted	(54,000	)	54,000		$	0.46
Options cancelled	113,060		(62,435	)	$	1.72
Balances at March 31, 2023	455,074		2,102,944		$	7.35
Options granted	(377,500	)	377,500		$	0.16
Options cancelled	167,868		(157,868	)	$	0.16
Balances at June 30, 2023	245,442		2,322,576		$	6.18
Options granted	(185,000	)	185,000		$	0.08
Options cancelled	65,827		(45,827	)	$	1.66
Balances at September 30, 2023	126,269		2,322,576		$	6.27

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2023			2022			2023			2022
Expected term (in years)		6.00			6.00			6.00			6.00
Expected volatility		99%-100	%		99%-100	%		99%- 100	%		99%- 100	%
Risk-free interest-rate		4.43	%		2.44% - 3.03	%		3.31% - 4.43	%		1.72% - 3.03	%
Dividend yield		0	%		0	%		0	%		0	%

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The following table presents stock-based compensation expense related to stock options and RSUs (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2023		2022		2023		2022
	(unaudited)		(unaudited)		(unaudited)		(unaudited)
Research and development	$	135	$	159	$	428	$	385
General and administrative		65		190		227		776
Total	$	200	$	349	$	655	$	1,161