Stock-Based Compensation Plan (Tables)

6 Months Ended

Jun. 30, 2023

Stock-Based Compensation Plan

Summary of weighted-average assumptions

The Company utilized the Black-Scholes valuation model for estimating the fair value of the stock options granted, with the following weighted-average assumptions for options granted in the six months ended June 30, 2023 and 2022, respectively:

	2023		2022
Risk-free interest rate	3.42	%	2.43	%
Expected volatility	129	%	127	%
Expected term in years	6.0		6.0
Dividend yield	—	%	—	%

Schedule of option activity under stock-based compensation plans

The following summary represents option activity under the Company’s stock-based compensation plans for the six months ended June 30, 2023:

		Weighted-
		Average
		Exercise
	Options	Price
	(in thousands)
Outstanding at December 31, 2022	658	$	11.67
Granted	221		1.39
Outstanding at June 30, 2023	879	$	9.09
Vested and expected to vest June 30, 2023	822	$	9.23
Exercisable at June 30, 2023	428	$	15.18