Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2022

Stock-based Compensation

Schedule of stock based compensation

The following table summarizes total stock-based compensation expense for the three months ended March 31, 2022 and 2021 (in thousands). The stock-based compensation expense during the three months ended March 31, 2022 and 2021 was mostly related to the applicable portion vesting during this period of stock options awards made prior to 2021.

	For the three months ended
	March 31,
	2022		2021
Research and development	$	510	$	3,689
General and administrative		107		6,129
Total stock-based compensation expense	$	617	$	9,818

Schedule of weighted average assumptions for stock options modification

	For the three months
	ended
	March 31, 2022
Exercise price	$	0.77
Expected term (years)		5.0
Expected stock price volatility		95	%
Risk-free rate		1.4	%
Dividend yield (per share)		0	%

Schedule of stock option activity

The following table summarizes stock option activity for the Company’s option plans during the three months ended March 31, 2022 (amount in thousands, except per share number):

				Weighted
				Average
		Weighted		Remaining
	Number of	Average Exercise		Contractual Life	Total Intrinsic
	Shares	Price		(in years)	Value
Outstanding as of January 1, 2022	304,847	$	0.33	8.0	$	114,803
Granted	20		0.77	10.0		—
Outstanding as of March 31, 2022	304,867	$	0.33	7.7	$	114,803
Options vested (1)	284,728	$	0.32	7.7	$	108,032

(1) Approximately 237 million options are not exercisable until at least May 31, 2022.