Stock Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Options Valuation Assumptions Using a Black-Scholes Option Pricing Model

The assumptions used in the Black-Scholes option pricing model are as follows:

	For the Year ended December 31,
	2023	2022
Expected volatility	69.2% - 69.7%	68.7% - 70.1%
Weighted-average risk-free interest rate	3.45% - 4.22%	1.46% - 4.16%
Expected dividend yield	— %	— %
Expected term (in years)	5.5 - 6.25	5.5 - 6.25
Underlying common stock fair value	$0.92-$1.60	$1.40-$4.17

Summary of Option Activity under Plans

The following table summarizes the Company’s stock option activity during the year ended December 31, 2023:

	Number of Options			Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
								(in thousands)
Outstanding at January 1, 2023		9,865,734		$	10.96		7.2	$	493
Granted		3,188,150		$	1.53
Exercised		(26,166	)	$	0.61
Cancelled/Forfeited		(3,476,677	)	$	7.05
Outstanding at December 31, 2023		9,551,041		$	9.26		5.2	$	66
Vested and expected to vest at    December 31, 2023		9,551,041		$	9.26		5.2	$	66
Exercisable at December 31, 2023		7,061,128		$	11.35		4.3	$	66

Summary of Company's RSU Activity

The following table summarizes the Company's RSU activity for the year ended December 31, 2023:

	Number of Restricted Stock Units			Weighted- Average Grant Date Fair Value
Outstanding at January 1, 2023		543,179		$	6.12
Granted		483,850		$	1.60
Vested		(373,519	)	$	4.86
Forfeited		(312,171	)	$	2.59
Outstanding at December 31, 2023		341,339		$	2.95

Schedule of Stock-Based Compensation Expense

The Company recorded stock-based compensation expense related to stock options, shares purchased under the 2018 ESPP, restricted stock units and stock award modifications as follows:

	For the Year ended December 31,
	2023		2022
	(in thousands)
General and administrative	$	5,952	$	7,867
Research and development		1,372		5,187
	$	7,324	$	13,054