Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Stock-Based Compensation

Summary of fair value determined using the Black-Scholes option-pricing model

	December 31, 2022
Exercise price		$0.51-$3.10
Risk-free rate of interest		1.8%-4.36%
Expected term (years)		5.3-6.5
Expected stock price volatility		94.9%-147.8%
Dividend yield		—

Schedule of stock option activity

	Number of shares	Weighted average exercise price	Weighted average remaining contractual life (in years)	Aggregate intrinsic value (in thousands)
Outstanding as of December 31, 2022	2,548,849	$ 3.32	8.4	$ 618
Outstanding as of September 30, 2023	2,548,849	$ 3.32	7.6	$ 10
Options vested and exercisable as of September 30, 2023	2,022,085	$ 3.68	7.3	$ 10

Summary of recognition of stock-based compensation

The following table summarizes the Company’s recognition of stock-based compensation for the following periods (in thousands):

	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
Stock-based compensation expense
General and administrative	$	261	$	506	$	1,295	$	2,390
Research and development		90		35		295		472
Total stock-based compensation expense	$	351	$	541	$	1,590	$	2,862

Schedule of restricted stock activity

	Awards	Weighted Average Grant Date Fair Value
Balance as of December 31, 2022	1,000,000	$ 0.57
Vested	333,333	-
Balance as of September 30, 2023	666,667	$ 0.57