Equity (Tables)

3 Months Ended

Mar. 31, 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 March 31,
	2023		2022
Research and development expenses	$	256	$	1,264
General and administrative expenses	935		1,182
Total stock-based compensation expense	$	1,191	$	2,446

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 March 31,
	2023		2022
Expected volatility	85.95	%	83.18	%
Expected dividends	0	%	0	%
Expected terms (years)	6.04		6.07
Risk free rate	3.46	%	1.95	%

Schedule of Stock Option Activity

A summary of the Company’s stock option activity and related information for the three months ended March 31, 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	110,500	$	0.59
Options exercised	—	$	—
Options cancelled/forfeited	(3,302,276)	$	4.86
Outstanding at March 31, 2023	5,322,605	$	4.83	4.58	$	3
Exercisable as of March 31, 2023	4,195,975	$	5.41	3.41	$	—

Summary of RSU Activity

A summary of the Company’s RSU activity and related information for the three months ended March 31, 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	(151,250)	$	4.10
Non-vested at March 31, 2023	47,250	$	4.75