Stock-Based Awards (Tables)

6 Months Ended

Jun. 30, 2024

Share-Based Payment Arrangement [Abstract]

Valuation Assumptions of Stock Options Granted

The assumptions that the Company used to determine the grant-date fair value of the stock options granted to employees and directors during the six months ended June 30, 2024 were as follows, presented on a weighted average basis:

	Six Months Ended June 30,
	2024
Risk-free interest rate		4.3	%
Expected term (in years)		5.5
Expected volatility		105.7	%
Expected dividend yield		0	%

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity since January 1, 2024:

	Number of Shares			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding at December 31, 2023		2,212,102		$	7.42		6.0	$	2,905
Granted		205,450			3.12		—
Exercised		(88,068	)		1.16		—		—
Forfeited/Canceled		(49,246	)		3.28		—		—
Expired		(83,911	)		29.86		—		—
Outstanding at June 30, 2024		2,196,327			6.51		6.1		2,305
Options exercisable at June 30, 2024		1,902,866		$	6.55		5.8	$	2,175
Options vested and expected to vest at June 30, 2024		2,089,774		$	6.68		5.9	$	2,297
Options exercisable at December 31, 2023		1,882,191		$	7.46		5.8	$	2,631
Options vested and expected to vest at December 31, 2023		2,209,420		$	7.41		6.0	$	2,904

Summary of Stock Based Compensation Expense

The Company recorded stock-based compensation expense related to stock options in the following expense categories of its statements of operations and comprehensive loss:

	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Research and development expenses	$	37	$	71	$	76	$	190
General and administrative expenses		289		229		400		501
	$	326	$	300	$	476	$	691