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Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Stock Option Activity

A summary of the Company’s stock option activity under the 2021 Plan and 2018 Plan is as follows (in thousands, except share and per share data and years):

										Weighted-
						Weighted-				average remaining				Aggregate
						average				contractual				intrinsic
		Shares				exercise price				term (years)				value
Outstanding at December 31, 2020			6,541,422			$	0.98				9.23			$	15,571
Granted			8,320,187				5.93
Exercised			(736,200	)			1.88
Canceled			(307,197	)			2.97
Outstanding at December 31, 2021			13,818,212			$	3.87				8.82			$	163,264
Options exercisable at December 31, 2021			3,161,831			$	1.63				8.29			$	44,119

Summary of Restricted Stock Activity

The summary of the Company’s restricted stock activity during the year ended December 31, 2021 is as follows:

		Number of				Weighted-
		restricted				average
		stock shares				grant date
		outstanding				fair Value
Nonvested at December 31, 2020			557,731			$	0.001
Vested			(344,790	)			0.001
Nonvested at December 31, 2021			212,941			$	0.001

Schedule of Stock-based Compensation Expense

The allocation of stock-based compensation for all stock awards was as follows (in thousands):

		Year Ended December 31,
		2021				2020
Research and development		$	4,957			$	348
General and administrative			3,374				449
Total		$	8,331			$	797

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consisted of the following as of December 31, 2021 and 2020:

		December 31,				December 31,
		2021				2020
Conversion of preferred stock outstanding			—				57,987,216
Conversion of preferred stock in future issuance (B-2)			—				10,979,319
Stock options issued and outstanding			13,818,212				6,541,422
Awards available for future grant			14,699,430				2,314,746
Shares available for purchase under the ESPP			1,168,013				—
Total			29,685,655				77,822,703

Stock Options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Assumptions used to Determine Fair Value of Stock Option Grants and Stock to be Purchased under ESPP

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

		Year Ended December 31,
		2021		2020
Risk-free interest rate		0.59%-1.34%		0.37%-1.22%
Expected volatility		81.93%-85.35%		74.72%-77.81%
Expected term (in years)		6.08		6.02-6.25
Expected dividend yield		--%		--%

ESPP

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Assumptions used to Determine Fair Value of Stock Option Grants and Stock to be Purchased under ESPP

The assumptions used in the Black-Scholes option pricing model to determine the fair value of the stock to be purchased under the ESPP were as follows:

		Year Ended December 31,
		2021		2020(1)
Risk-free interest rate		0.05%-0.64%		--%
Expected volatility		70.99%-91.69%		--%
Expected term (in years)		0.39-2.00		--
Expected dividend yield		--%		--%

The ESPP was not in effect until 2021

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Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year.

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