Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2022

Summary of Stock Option Activity Under Equity Incentive Plans

The following table summarizes stock option activity under the Company’s equity incentive plans since December 31, 2021:

	Options Outstanding			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value (1)
						(in years)		(in thousands)
Outstanding at December 31, 2021		3,582,613		$	10.63		8.32	$	7,428
Granted		1,505,019			5.21
Exercised		(151,342	)		1.61
Forfeited		(195,846	)		10.76
Outstanding at June 30, 2022		4,740,444		$	9.20		8.43	$	4,092
Exercisable at June 30, 2022		1,795,985		$	8.84		7.51	$	2,758
Vested and expected to vest at June 30, 2022		4,740,444		$	9.20		8.43	$	4,092

(1) The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock.

Summary of Assumptions Used to Value Stock Options Granted Using Black-Scholes Option-Pricing

The underlying assumptions used to value stock options granted to participants using the Black-Scholes option-pricing were as follows:

	For the Three Months Ended June 30,		For the Six Months Ended June 30,
	2022	2021	2022	2021
Risk-free interest rate range	2.52% to 3.22%	0.92% to 1.15%	1.58% to 3.22%	0.48% to 1.15%
Dividend yield	0%	0%	0%	0%
Expected term of options (years)	5.38 to 6.08	5.37 to 6.08	5.08 to 6.48	5.37 to 6.48
Volatility rate range	85.04% to 87.15%	90.34% to 91.19%	85.04% to 87.15%	88.70% to 91.19%

Summary of Total Compensation Cost Recognized in Statements of Operations

The total compensation cost recognized in the statements of operations associated with all the stock-based compensation awards granted by the Company is as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	1,096	$	1,056	$	1,992	$	1,697
General and administrative		1,089		757		1,945		1,693
Total	$	2,185	$	1,813	$	3,937	$	3,390