Equity (Tables)

6 Months Ended

Jun. 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 June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development expenses	$	—	$	1,051	$	255	$	2,315
General and administrative expenses	331		1,261		1,267		2,443
Total stock-based compensation expense	$	331	$	2,312	$	1,522	$	4,758

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 June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Expected volatility	87.37	%	82.68	%	86.77	%	83.01	%
Expected dividends	0	%	0	%	0	%	0	%
Expected terms (years)	5.27		5.73		5.60		5.96
Risk free rate	3.82	%	2.77	%	3.67	%	2.22	%

Schedule of Stock Option Activity

A summary of the Company’s stock option activity and related information for the six months ended June 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	8,514,381	$	4.89	8.32	$	—
Options granted	260,500	$	0.70
Options exercised	—	$	—
Options cancelled/forfeited	(4,138,321)	$	5.07
Outstanding at June 30, 2023	4,636,560	$	3.96	4.41	$	11
Exercisable as of June 30, 2023	3,534,712	$	4.51	3.01	$	—

Summary of RSU Activity

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

	Number of Shares	Weighted Average Grant Date Fair Value
Non-vested at December 31, 2022	378,500	$	4.22
Restricted stock units granted	—	$	—
Restricted stock units vested	(180,000)	$	4.18
Restricted stock units forfeited	(152,250)	$	4.15
Non-vested at June 30, 2023	46,250	$	4.59