Equity (Tables)

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Summary of Stock-based Compensation Expense

Stock-based compensation expense is classified in the condensed statements of operations and comprehensive income (loss) as follows:

(in thousands)	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development expenses	$	—	$	973	$	252	$	3,288
General and administrative expenses	172		1,058		1,442		3,501
Total stock-based compensation expense	$	172	$	2,031	$	1,694	$	6,789

Schedule of Weighted Average Assumptions

The fair values of stock options granted are estimated using the Black-Scholes option pricing model with the following weighted average assumptions:

	Three Months Ended September 30,			Nine Months Ended September 30,
	2023	2022		2023		2022
Expected volatility	—	84.18	%	86.77	%	83.80	%
Expected dividends	—	0	%	0	%	0	%
Expected terms (years)	—	6.08		5.60		6.04
Risk free rate	—	2.83	%	3.67	%	2.63	%

Schedule of Stock Option Activity

A summary of the Company’s stock option activity and related information for the nine months ended September 30, 2023 is as follows:

	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life  (in Years)	Aggregate Intrinsic Value (in Thousands)
Outstanding at December 31, 2022	1,702,833	$	24.47	8.32	$	—
Options granted	52,100	$	3.52
Options exercised	—	$	—
Options cancelled/forfeited	(859,867)	$	27.06
Outstanding at September 30, 2023	895,066	$	19.70	4.03	$	4
Exercisable as of September 30, 2023	738,616	$	21.90	3.04	$	—

Summary of RSU Activity

A summary of the Company’s RSU activity and related information for the nine months ended September 30, 2023 is as follows:

	Number of Shares	Weighted Average Grant Date Fair Value
Non-vested at December 31, 2022	75,700	$	21.09
Restricted stock units granted	—	$	—
Restricted stock units vested	(37,000)	$	21.95
Restricted stock units forfeited	(32,950)	$	20.59
Non-vested at September 30, 2023	5,750	$	18.45