Stock Option Plans (Tables)

12 Months Ended

Dec. 31, 2022

Stock Option Plans

Schedule of stock option activity

Activity under the Company’s stock option plans is set forth below:

		Options Outstanding
			Weighted ‑
	Shares		Average
	Available	Number of	Exercise
	for Grant	Options	Price
Balance at December 31, 2021	2,806,953	6,354,308	$	6.80
Additional shares authorized	1,862,000	—		—
Options granted	(1,706,400)	1,706,400		1.02
Options forfeited	1,054,458	(1,054,458)		7.75
Balance at December 31, 2022	4,017,011	7,006,250	$	5.25

Schedule of options outstanding and exercisable that had vested or were expected to vest

Options outstanding that had vested or were expected to vest at December 31, 2022 were as follows:

				Weighted
				Average	Aggregate
		Weighted		Remaining	Intrinsic
	Number	Average		Contractual	Value
	of shares	Exercise Price		Life (years)	(in thousands)
Vested	4,121,317	$	7.51	5.95	$	19.95
Expected to vest	2,884,933	$	2.02	8.94	$	—