Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Schedule of Restricted Stock Units Activity

The Company’s RSU activity for the nine months ended September 30, 2021 was as follows:

				Weighted
				Average
				Grant Date
	Number			Fair Value
	of Shares			per Share
Nonvested at January 1, 2021		2,850,053		$	6.37
Restricted units granted		—			—
Vested		(712,510	)		6.37
Cancelled or forfeited		(250,778	)		5.25
Nonvested at September 30, 2021		1,886,765		$	6.52

Schedule of Restricted Stock Awards Activity

The Company’s RSA activity for the nine months ended September 30, 2021 was as follows:

				Weighted
				Average
				Grant Date
	Number			Fair Value
	of Shares			per Share
Nonvested at December 31, 2020		769,058		$	5.28
Restricted stock granted		—			—
Vested		(362,963	)		5.28
Nonvested at September 30, 2021		406,095		$	5.28

Schedule of Total Stock-Based Compensation Expense for Stock Options, RSAs and RSUs (Detail)

The following table summarizes the total stock-based compensation expense for the stock options, RSAs and RSUs recorded in the condensed consolidated statements of operations for the three and nine months ended September 30, 2021 and 2020 (in thousands):

	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
	2021		2020		2021		2020
Research and development expense	$	2,305	$	399	$	6,098	$	399
General and administrative expense		2,781		942		7,131		942
Total	$	5,086	$	1,341	$	13,229	$	1,341

Stock Options

Schedule of Assumptions Used to Estimate Fair Value of Stock Options and Cancelled Options

The following weighted-average assumptions were used to estimate the fair value of stock options that were granted during the three and nine months ended September 30, 2021 and 2020:

	Three months ended September 30,						Nine months ended September 30,
	2021			2020			2021			2020
Risk-free interest rate		1.02	%		0.46	%		0.83	%		0.46	%
Expected dividend yield	—				—		—				—
Expected term in years		6.1			6.7			6.0			6.7
Expected volatility		75	%		80	%		75	%		80	%

Schedule of Stock Option Activity

The following table summarizes stock option activity, during the nine months ended September 30, 2021:

						Weighted
				Weighted		Average		Aggregate
				Average		Remaining		Intrinsic
	Stock			Exercise		Contractual		Value
	Options			Price		Life (in years)		(in thousands)
Outstanding at December 31, 2020		674,842			20.68		9.8	$	3,953
Options granted		3,001,750			25.46
Options cancelled or forfeited		(159,600	)		27.14
Outstanding at September 30, 2021		3,516,992		$	24.47		9.4	$	175
Vested and expected to vest at September 30, 2021		3,516,992		$	24.47		9.4	$	175
Options exercisable at September 30, 2021		84,349		$	20.08		9.0	$	17