Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2024

Schedule of stock option activity

		Weighted		Weighted-
		Average		Average	Aggregate
		Exercise		Contractual	Intrinsic
	Options Outstanding	Price Per Share		Life (in years)	Value
Outstanding, December 31, 2023	7,049,290	$	$ 0.82	8.23	$	2,017
Granted	1,605,070		1.51
Exercised	(249,531)		0.27		$	311
Forfeited and expired	(22,015)		0.27
Outstanding and expected to vest, June 30, 2024	8,382,814		0.97	8.22		2,238
Exercisable, June 30, 2024	3,377,648	$	0.57	6.75	$	1,895

Schedule of activity related to restricted stock units

The following is a summary of RSU activity during the six months ended June 30, 2024:

		Weighted Average
		Grant Date Fair
	Shares	Value
Non-vested at December 31, 2023	11,517,422	$	2.20
Granted	1,567,515		1.46
Forfeited	(683,416)		1.71
Vested	(2,800,719)		2.50
Non-vested at June 30, 2024	9,600,802	$	$ 2.04

Schedule of total stock-based compensation expenses

The table below summarizes total stock-based compensation expenses for the three and six months ended June 30, 2024 and 2023, respectively (in thousands):

:

	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Research and development	$	2,262	$	2,375	$	4,189	$	3,902
Selling, general and administrative expenses		1,025		980		2,089		1,156
Total stock-based compensation expenses	$	3,287	$	3,355	$	6,278	$	5,058

Stock Options

Schedule of weighted average assumptions used as inputs in the valuation of stock options granted

	Time-based Stock Option
Valuation Assumptions	Grants
Strike price	$0.98 - $2.03
Annual volatility (%)	113% - 130%
Risk- free rate (%)	4.24% - 4.45%
Expected term (years)	5.50 - 6.02