Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Stock-Based Compensation

Schedule of stock-based compensation expense

Stock-based compensation expense as reflected in the Company’s condensed consolidated statements of operations and comprehensive loss was as follows:

	Three months ended June 30,				Six months ended June 30,
	2023		2022		2023		2022
	(in thousands)
Research and development	$	106	$	191	$	301	$	274
General and administrative		638		646		1,907		1,190
Stock-based compensation expense included in operating expenses	$	744	$	837	$	2,208	$	1,464

Summary of stock option activity

The following is a summary of the Company’s stock option activity for the six months ended June 30, 2023:

		Weighted-		Weighted- average	Aggregate
		average		remaining contractual	intrinsic value
	Options	exercise price		term (in years)	(in thousands)
Outstanding at December 31, 2022	4,408,274	$	3.44	8.52	$	350
Granted	2,257,506		1.08
Exercised	(1,239,899)		1.18
Cancelled	(1,006,332)		2.73
Outstanding at June 30, 2023	4,419,549		3.03	8.70	$	1,454
Vested at June 30, 2023	2,132,303		3.34	5.37	$	476
Vested and expected to vest at June 30, 2023	4,419,549	$	3.03	8.70	$	1,454

The following is a summary of the Company’s stock option activity for the six months ended June 30, 2022:

		Weighted-		Weighted- average	Aggregate
		average		remaining contractual	intrinsic value
	Options	exercise price		term (in years)	(in thousands)
Outstanding at December 31, 2021	3,021,799	$	3.71	8.94	$	10,903
Granted	1,436,995		3.32
Exercised	(44,105)		0.43
Cancelled	(232,987)		4.24
Outstanding at June 30, 2022	4,181,702		3.58	9.07	$	697
Vested at June 30, 2022	1,097,333		2.53	8.65	$	435
Vested and expected to vest at June 30, 2022	4,181,702	$	3.58	9.07	$	697

Schedule of assumptions used in estimation of fair value

	Three months ended June 30,				Six months ended June 30,
	2023		2022		2023		2022
Risk-free interest rate	3.94	%	2.84 - 3.34	%	3.67 - 4.24	%	1.62 - 3.34	%
Volatility	72	%	75 - 80	%	72 - 74	%	75 - 80	%
Dividend yield	0.00	%	0.00	%	0.00	%	0.00	%
Expected term (years)	7		6		2-7		6

Summary of restricted stock units activity

The following table summarizes activity related to RSUs:

		Weighted- average
		grant date
	Number of shares	fair value
Unvested at December 31, 2022	125,622	$	16.00
Granted	96,025		0.98
Vested	(25,125)	$	16.00
Unvested at June 30, 2023	196,522	$	8.66