Stockholders' Equity (Deficit) (Tables)

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Summary of the Authorized, Issued and Outstanding Shares of Convertible Preferred Stock

The authorized, issued and outstanding shares of convertible preferred stock as of December 31, 2020 consist of the following (in thousands, except share and per share amounts):

	Shares Authorized		Shares Issued and Outstanding		Per Share Original Issue Price		Liquidation Value		Carrying Value
Series A		14,979,200		14,979,200	$	0.50	$	7,490	$	7,391
Series B		26,666,667		26,666,667		0.75		20,000		19,901
Series C		53,176,000		53,063,500		1.00		53,064		52,937
Series D-1		66,155,067		66,155,067		0.76		49,933		45,794
Series D-2		94,007,051		—		—		—		—
Total		254,983,985		160,864,434			$	130,487	$	126,023

Summary of Stock Option Activity

The Company’s stock option activity for the year ended December 31, 2021 is summarized in the following table:

	Number			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2020		2,930,248		$	2.90		9.3	$	2,290
Granted		3,943,984		$	18.23
Exercised		(151,436	)	$	1.57
Cancelled/forfeited		(248,757	)	$	5.44
Outstanding at December 31, 2021		6,474,039		$	12.18		8.5	$	177,130
Vested or expected to vest at December 31, 2021		6,474,039		$	12.18		8.5	$	177,130
Exercisable at December 31, 2021		1,505,832		$	3.51		6.1	$	54,256

Summary of Grant Date Fair Value of Stock Options

The grant date fair value of stock options was determined using the Black-Scholes option pricing model with the following assumptions:

	Year Ended December 31,
	2021	2020
Risk-free interest rate	0.2 – 1.4%	0.2 – 1.4%
Expected volatility	73.0 – 95.2%	61.5 – 71.8%
Expected term (in years)	5.3 – 6.1	6.1
Expected dividend yield	—%	—%

Summary of Activity Unvested Common Stock Issued Pursuant Early Exercise of Stock Options Awards

The following table summarizes the activity of the unvested common stock issued pursuant to an early exercise of stock option awards:

	Year Ended December 31,
	2021			2020
Unvested at beginning of year		54,703			70,266
Early exercised stock options during the period		—			23,540
Early exercised stock options repurchased during the period		—			(4,480	)
Vested during the period		(37,097	)		(34,623	)
Unvested at end of year		17,606			54,703

Summary of Fair Value of Stock of the Stock Purchase Right Under ESPP

The fair value of stock of the stock purchase right under the ESPP was determined using the Black-Scholes option pricing model with the following assumptions:

	Year Ended December 31,
	2021
Risk-free interest rate	0.03– 0.33%
Expected volatility	71.6 – 83.9%
Expected term (in years)	0.5 – 1.64
Expected dividend yield	—%

Summary of Stock-based Compensation Expense

The following table summarizes the components of stock-based compensation expense recognized in the accompanying statements of operations (in thousands):

	Year Ended December 31,
	2021		2020
Research and development	$	1,755	$	144
General and administrative		8,943		595
Discontinued operations		—		101
Total stock-based compensation	$	10,698	$	840

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following:

	December 31, 2021		December 31, 2020
Conversion of convertible preferred stock issued		—		16,086,426
Conversion of convertible preferred stock in future issuance (D-2)		—		9,400,705
Common stock options issued and outstanding		6,474,039		2,930,248
Warrants to purchase convertible preferred stock outstanding		—		11,250
Warrants to purchase common stock outstanding		14,884		—
Shares available for issuance under equity incentive plan		1,856,063		373,789
Shares available for issuance under the ESPP		333,850		—
Total		8,678,836		28,802,418