Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Share-Based Compensation Expense Related to Stock Options

The Company recorded stock-based compensation expense in the following expense categories of its condensed statements of operations for the periods shown (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
General and administrative	$	1,058	$	510	$	2,016	$	962
Research and development	463		205		895		371
Total stock-based compensation	$	1,521	$	715	$	2,911	$	1,333

Summary of Assumptions Used for Valuation of Fair Value of Stock Options

The Black-Scholes option-pricing model was used to estimate the fair value of stock options granted during the six months ended June 30, 2023 and 2022 with the following weighted average assumptions:

	Six Months Ended June 30,
	2023	2022
Risk-free interest rate	3.47% - 4.13%	1.71% - 3.38%
Expected term (in years)	5.5 - 6.1	5.8 - 6.1
Expected volatility	90%	90%
Expected dividend yield	0%	0%

Summary of Stock Option Activity

The following table reflects summarized stock option activity:

	Stock Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2023	5,610,893	$	3.36
Granted	1,793,600	$	5.90
Forfeited	(12,000)	$	3.23
Expired	(2,104)	$	22.39
Outstanding at June 30, 2023	7,390,389	$	3.97	8.1	$	12,580
Vested and exercisable at June 30, 2023	3,285,716	$	2.80	7.2	$	8,819

Summary of Nonvested Restricted Stock Units Activity

	Number of Shares	Weighted Average Grant Date Fair Value
Unvested as of January 1, 2023	—	$	—
Granted	328,500	$	6.11
Unvested at June 30, 2023	328,500	$	6.11