Common Stock and Stock-Based Awards (Tables)

12 Months Ended

Dec. 31, 2022

Subsidiary, Sale of Stock [Line Items]

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity for the year ended December 31, 2022:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
						(in years)
Outstanding as of December 31, 2021		11,517,189		$	11.10		7.42	$	28,007
Granted		4,527,897			6.89
Exercised		(326,864	)		2.96
Forfeited		(778,188	)		10.62
Outstanding as of December 31, 2022		14,940,034		$	10.03		7.25	$	11,608
Options exercisable as of December 31, 2022		7,441,253		$	10.38		5.88	$	8,115

Summary of Restricted Stock Activity

The Company has granted restricted stock units ("RSUs") with service-based vesting conditions.The table below summarizes the Company’s RSU activity for the year ended December 31, 2022:

	Number of Shares			Weighted Average Grant Date Fair Value
Unvested restricted stock units as of December 31, 2021		734,755		$	17.68
Granted		1,302,844		$	6.95
Forfeited		(205,658	)	$	11.82
Vested		(282,401	)	$	18.06
Unvested restricted stock units as of December 31, 2022		1,549,540		$	9.37

Summary of Stock Based Compensation Expense

The Company recorded stock-based compensation expense related to stock options and restricted stock units in the following expense categories of its consolidated statements of operations and comprehensive loss:

	Year Ended December 31,
	2022		2021		2020
Research and development expenses	$	13,429	$	10,146	$	4,760
General and administrative expenses		12,053		10,076		4,064
	$	25,482	$	20,222	$	8,824

Employee Stock [Member]

Subsidiary, Sale of Stock [Line Items]

Summary of Estimated Fair Value of Employee Stock Options

The assumptions that the Company used to determine the fair value of rights to acquire common stock under the ESPP were as follows, presented on a weighted average basis:

	Year Ended December 31,
	2022			2021			2020
Risk-free interest rate		2.11	%		0.97	%		1.20	%
Expected term (in years)		0.5			0.5			0.5
Expected volatility		99.0	%		123.8	%		74.9	%
Expected dividend yield		0	%		0	%		0	%

Employees Stock Option [Member]

Subsidiary, Sale of Stock [Line Items]

Summary of Estimated Fair Value of Employee Stock Options

The assumptions that the Company used to determine the fair value of the stock options granted to employees and directors were as follows, presented on a weighted average basis:

	Year Ended December 31,
	2022			2021			2020
Risk-free interest rate		1.67	%		0.73	%		1.26	%
Expected term (in years)		6.0			5.4			6.0
Expected volatility		104.0	%		106.5	%		73.3	%
Expected dividend yield		0	%		0	%		0	%