11. Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Valuation Assumptions for Stock Options

The following assumptions were used in determining the fair value of the stock options granted during the six months ended June 30, 2022 and 2021:

		Six Months Ended
		June 30, 2022		June 30, 2021
Risk-free interest rate		1.5% - 1.6%		0.5% - 1.2%
Volatility		113%		120%-125%
Dividend yield		-%		-%
Expected term (years)		5 - 6		5 - 6
Weighted-average fair value	$	1.24	$	3.62

Summary of Stock Option Activity

A summary of stock option activity during the six months ended June 30, 2022 is as follows (share amounts in thousands):

				Weighted-
			Weighted-	Average		Total
			Average	Remaining		Aggregate
	Stock		Exercise	Contractual		Intrinsic
	Options		Price	Life (in years)		Value
Outstanding as of December 31, 2021	7,306	$	2.60
Granted	3,000		1.47
Exercised	(6)		1.06
Cancelled	-		-
Outstanding as of June 30, 2022	10,300	$	2.27	8.5	$	1
Vested and expected to vest as of June 30, 2022	10,300	$	2.27	8.5	$	1
Exercisable as of June 30, 2022	3,553	$	2.88	7.9	$	1

Schedule of Stock-Based Compensation Expense

The following table summarizes the total stock-based compensation expense resulting from share-based awards recorded in the Company’s condensed consolidated statements of operations (in thousands):

		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2022		2021		2022		2021
Research and development	$	231	$	222	$	460	$	358
General and administrative		730		815		2,733		1,384
	$	961	$	1,037	$	3,193	$	1,742