Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Schedule of Restricted Stock Units Activity

The Company’s RSU activity for the six months ended June 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		(629,730	)		5.25
Cancelled or forfeited		(167,186	)		5.25
Nonvested at June 30, 2021		2,053,137		$	6.80

Schedule of Restricted Stock Awards Activity

The Company’s RSA activity for the six months ended June 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		(298,843	)		5.28
Nonvested at June 30, 2021		470,215		$	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 six months ended June 30, 2021 (in thousands):

	For the Three Months Ended June 30, 2021		For the Six Months Ended June 30, 2021
Research and development expense	$	2,214	$	3,793
General and administrative expense		2,335		4,350
Total	$	4,549	$	8,143

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 six months ended June 30, 2021:

	Three months ended June 30, 2021			Six months ended June 30, 2021
Risk-free interest rate		1.07	%		0.80	%
Expected dividend yield	—			—
Expected term in years		6.0			6.0
Expected volatility		76	%		75	%

Schedule of Stock Option Activity

The following table summarizes stock option activity, during the six months ended June 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		2,586,650			26.41
Options cancelled or forfeited		(47,800	)		28.61
Outstanding at June 30, 2021		3,213,692		$	25.18		9.6	$	786
Vested and expected to vest at June 30, 2021		3,213,692		$	25.18		9.6	$	786
Options exercisable at June 30, 2021		43,054		$	20.50		9.3	$	37