Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Option Activity

The following table summarizes the status of the Company’s stock option activity granted under the Plans to employees, directors, and consultants (aggregate intrinsic value in thousands):

	Stock Options			Weighted- Average Exercise price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding at December 31, 2021		12,662,070		$	8.96		4.88	$	—
Granted		171,500			0.60		—		—
Forfeited and expired		(647,365	)		7.84		—		—
Outstanding at June 30, 2022		12,186,205		$	8.90		4.45	$	—
Vested and exercisable at June 30, 2022		10,029,540		$	9.08		3.64	$	—

Schedule of Weighted-Average Assumptions Used as Inputs to Black-Scholes Option Pricing Model

The following table summarizes the weighted-average assumptions used as inputs to the Black-Scholes model during the periods indicated:

	Six Months Ended June 30,
	2022			2021
Weighted average grant date fair value	$	0.60		$	6.18
Expected dividend yield		—	%		—	%
Expected stock price volatility		66	%		68	%
Risk-free interest rate		2.72	%		1.45	%
Expected life of options (in years)		5.3			6.3

Schedule of Status of Restricted Stock Awards

The following table summarizes the status of the Company's restricted stock awards.

	Shares of Restricted Stock			Weighted Average Fair Value
Nonvested at December 31, 2021		924,595		$	3.86
Granted		50,000			0.83
Forfeited		(151,540	)		3.64
Nonvested at June 30, 2022		823,055		$	3.52

Schedule of Stock-Based Compensation Cost

The components of stock-based compensation and the amounts recorded within cost of sales, research and development expenses and selling, general, and administrative expenses in the Company’s consolidated statements of operations and comprehensive loss consisted of the following for the three and six months ended June 30, 2022 and 2021 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Stock options	$	1,321	$	2,341	$	2,924	$	4,500
Restricted stock expense		245		57		496		86
Employee stock purchase plan		37		46		57		92
Total stock-based compensation expense	$	1,603	$	2,444	$	3,477	$	4,678
Cost of sales	$	52	$	59	$	78	$	115
Research and development expenses		395		671		964		1,272
Selling, general, and administrative expenses		1,156		1,714		2,435		3,291
Total stock-based compensation expense	$	1,603	$	2,444	$	3,477	$	4,678