Stock-Based Compensation Plan (Tables)

12 Months Ended

Dec. 31, 2022

Stock-Based Compensation Plan

Summary of weighted-average assumptions

	2022		2021
Risk-free interest rate	2.43	%	1.15	%
Expected volatility	127	%	128	%
Expected term in years	6.0		6.0
Dividend yield	—	%	—	%

Schedule of option activity under stock-based compensation plans

Option activity under the Plans for the year ended December 31, 2022 was as follows (in thousands, except as noted):

				Weighted
		Weighted-		Average
		Average		Remaining		Aggregate
		Exercise		Contractual		Intrinsic
	Options	Price		Term		Value
	(in thousands)
Outstanding at December 31, 2021	486	$	14.58		8.4	$	7,800
Granted	192		3.71		9.3
Forfeited	(2)		7.02
Expired	(18)		5.96
Outstanding at December 31, 2022	658	$	11.67		7.9	$	—
Vested and expected to vest December 31, 2022	634	$	11.90		7.9	$	—
Exercisable at December 31, 2022	321	$	18.62		7.3	$	—

Option activity under the Plans for the year ended December 31, 2021 was as follows (in thousands, except as noted):

				Weighted
		Weighted-		Average
		Average		Remaining		Aggregate
		Exercise		Contractual		Intrinsic
	Options	Price		Term		Value
	(in thousands)
Outstanding at December 31, 2020	274	$	20.57		8.7	$	3,750
Granted	213		7.02		9.3
Expired	(1)		72.67
Outstanding at December 31, 2021	486	$	14.58		8.4	$	7,800
Vested and expected to vest December 31, 2021	451	$	15.21		8.4	$	7,114
Exercisable at December 31, 2021	178	$	28.09		7.6	$	3,412