Convertible Preferred Stock and Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2022

Summary of Stock Option Activities

A summary of the Company’s stock option activities during the six months ended June 30, 2022 is as follows:

		Weighted-		Weighted-
		Average		Average	Aggregate
		Exercise		Remaining	Intrinsic
		Price Per		Contract	Value (in
	Total Options	Share		Term (in years)	millions)
Outstanding as of December 31, 2021	1,734,696	$	8.50	8.8	$	7.6
Granted	889,952	$	8.80
Exercised	(27,262)	$	4.30
Forfeited or cancelled	(194,514)	$	11.20
Outstanding as of June 30, 2022	2,402,872	$	8.44	8.8	$	2.0
Vested and expected to vest as of June 30, 2022	2,402,872	$	8.44	8.8	$	2.0
Vested and exercisable as of June 30, 2022	801,929	$	5.75	7.9	$	1.3

Summary of Stock-Based Compensation Expense Recognized

The Company recognized stock-based compensation expense as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	1,203	$	634	$	2,093	$	768
General and administrative		214		159		566		190
Total stock-based compensation expense	$	1,417	$	793	$	2,659	$	958

Weighted-Average Assumptions Used in Black-Scholes Option Pricing Model to Determine Fair Value of Stock Option Grants

The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the stock option grants were as follows:

	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Risk-free interest rate	2.95% - 3.02%	0.81% - 1.12%	1.60% - 3.02%	0.80% - 1.12%
Expected volatility	88.1% - 90.2%	115.3% -116.6%	88.1% - 112.1%	115.3% -118.7%
Expected term (in years)	5.3 - 6.1	5.0 - 6.1	5.3 - 6.1	5.0 - 6.1
Expected dividend yield	0%	0%	0%	0%

Schedule of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consist of the following:

	June 30, 2022	December 31, 2021
Stock options	2,402,872	1,734,696
Reserved for future equity award grants	3,297,524	2,933,930
Reserved for future ESPP issuances	497,643	259,689
Total	6,198,039	4,928,315

Employee Stock Purchase Plan

Weighted-Average Assumptions Used in Black-Scholes Option Pricing Model to Determine Fair Value of Stock Option Grants

The weighted average assumptions used in Black-Scholes option pricing model to estimate the fair value of purchase rights granted under the ESPP were as follows:

	Six months ended June 30,
	2022
Risk-free interest rate	0.1%
Expected volatility	133.6%
Expected term (in years)	1.7
Expected dividend yield	0%