Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Options Activity

The following table sets forth the activity for the Company’s stock options during the six months ended June 30, 2022:

	Number of Options			Weighted- average exercise price per share		Weighted- average remaining contractual term (in years)		Aggregate intrinsic value
Outstanding at December 31, 2021		3,998,728		$	6.51		8.3	$	1,357,655
Granted		1,774,750			3.01		—		110,313
Cancelled		(13,334	)		4.10		—		—
Outstanding at June 30, 2022		5,760,144		$	5.44		8.4	$	—
Vested and expected to vest at June 30, 2022		5,456,002		$	5.44		8.7	$	—
Vested and exercisable at June 30, 2022		2,166,299		$	5.49		7.3	$	—

Summary of Stock-based Compensation Expense

The Company recorded stock-based compensation expense related to the issuance of stock as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	670	$	449	$	1,323	$	856
General and administrative		749		538		1,500		1,162
Total stock-based compensation	$	1,419	$	987	$	2,823	$	2,018

The Company uses a Black-Scholes option pricing model to determine fair value of its stock options. The Black-Scholes option pricing model includes various assumptions, including the fair value of common shares, expected life of stock options, the expected volatility based on the historical volatility of a publicly traded set of peer companies and the expected risk-free interest rate based on the implied yield on a U.S. Treasury security.

Summary of Fair Value Assumptions of Options Granted

The fair values of the options granted were estimated using the following assumptions:

	Six Months Ended
	June 30,
	2022			2021
Risk-free interest rate		1.7	%		0.7	%
Expected term (in years)		6.0			6.0
Expected volatility		90.0	%		90.5	%
Expected dividend yield		—			—