Note 11 - Stock-based Compensation

12 Months Ended

Dec. 31, 2022

Notes to Financial Statements

Share-Based Payment Arrangement [Text Block]

11. Stock-Based Compensation

Stock Plans

In January 2015, the Board of Directors adopted and the Company’s stockholders approved the 2015 Equity Incentive Plan (“2015 Plan”). The 2015 Plan provides for the grant of incentive stock options (“ISOs”) to employees and for the grant of non-statutory stock options (“NSOs”), restricted stock, restricted stock awards (“RSAs”), restricted stock units (“RSUs”), stock appreciation rights, performance units and performance shares to employees, directors and consultants. The shares reserved for issuance under the 2015 Plan includes share awards granted under the prior equity incentive plan that expire or terminate without having been exercised in full or that are forfeited or repurchased. On October 14, 2022, the Company’s stockholders approved an additional 1,750,000 shares of common stock for issuance under the 2015 Plan. As of December 31, 2022, 1,759,566 shares were available for grant under the 2015 Plan.

Pursuant to the 2015 Plan, ISOs and NSOs may be granted with exercise prices at not less than 100% of the fair value of the common stock on the date of grant and the exercise price of ISOs granted to a stockholder, who, at the time of grant, owns stock representing more than 10% of the voting power of all classes of the stock of the Company, shall be not less than 110% of the fair market value per share of common stock on the date of grant. The Company’s Board of Directors determines the vesting schedule of the options.

Stock option activity under the Plans is set forth below:

	Number of Shares (in thousands)			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Intrinsic Value (in thousands)
Balance at December 31, 2020		307		$	19,577.10		5.95	$	—
Options expired		(4	)	$	36,000.00
Balance at December 31, 2021		303		$	19,360.30		5.02	$	—
Balance at December 31, 2022		303		$	19,360.30		4.02	$	—
Exercisable at December 31, 2022		303		$	19,360.30		4.02	$	—
Vested and expected to vest at December 31, 2022		303		$	19,360.30		4.02	$	—

Additional information related to the Company’s stock options as of December 31, 2022 is summarized as follows:

Options Outstanding										Options Vested
						Weighted		Weighted				Weighted
						Average		Average				Average
Exercise				Options		Remaining		Exercise		Number		Exercise
Price				Outstanding		Contractual Life		Price		Exercisable		Price
$	334.00				155		5.44	$	334.00		155	$	334.00
$	16,400.00	-	28,400.00		31		4.18	$	17,323.87		31	$	17,323.87
$	36,000.00				103		2.00	$	36,000.00		103	$	36,000.00
$	103,680.00	-	162,000.00		14		2.85	$	112,097.14		14	$	112,097.14
					303		4.02	$	19,360.30		303	$	19,360.30

There were no options granted or exercised during either of the years ended December 31, 2022 or 2021. For the years ended December 31, 2022 and 2021, stock-based compensation expense recognized associated with stock options vesting was approximately $0 and $4,000, respectively. As of December 31, 2022, there is no remaining unamortized stock-based compensation expense associated with unvested stock options. Because of the Company’s net operating losses, the Company did not realize any tax benefits from share-based payment arrangements for the years ended December 31, 2022 and 2021.

The Company’s RSUs generally vest annually over three years in equal increments. The Company measures the fair value of RSUs using the closing stock price of a share of the Company’s common stock on the grant date and is recognized as expense on a straight-line basis over the vesting period of the award. A summary of all RSU activity is presented below:

	Number of Shares			Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term
Awards outstanding at December 31, 2020		20,671		$	76.03		0.98
Awarded		4,500		$	32.20
Released		(13,386	)	$	104.31
Forfeited		(1,725	)	$	53.62
Awards outstanding at December 31, 2021		10,060		$	24.39		0.72
Released		(8,590	)	$	25.02
Forfeited		(1,053	)	$	24.25
Awards outstanding at December 31, 2022		417		$	11.64		0.17

As of December 31, 2022, there was less than $0.1 million of remaining unamortized stock-based compensation expense associated with RSUs, which will be expensed over a weighted average remaining service period of 0.2 years. The outstanding non-vested and expected to vest RSUs at December 31, 2022 have an aggregate fair value of approximately less than $0.1 million. The Company used the closing market price of $1.09 per share at December 31, 2022 to determine the aggregate fair value for the RSUs outstanding at that date. For the years ended December 31, 2022 and 2021, the fair value of RSUs vested was approximately $14,000 and $273,000, respectively. For the years ended December 31, 2022 and 2021, stock-based compensation expense recognized associated with the vesting of RSUs was approximately $0.1 million and $1.0 million, respectively.

2018 Officer and Director Share Purchase Plan

On August 22, 2018, the Board of Directors of the Company approved the adoption of an Officer and Director Share Purchase Plan (“ODPP”), which allowed executive officers and directors to purchase shares of our common stock at fair market value in lieu of salary or, in the case of directors, director fees. Eligible individuals were allowed voluntarily participate in the ODPP by authorizing payroll deductions or, in the case of directors, deductions from director fees for the purpose of purchasing common stock. There was no common stock issued under the ODPP during either of the years ended December 31, 2022 or 2021. On May 16, 2022, the Board of Directors of the Company terminated the Amended and Restated Officer and Director Share Purchase Plan due to the administrative costs of maintaining such plan and the limited amount of remaining shares. Consequently, there are no longer any shares reserved for issuance under this plan.

Total noncash stock-based compensation expense relating to the Company’s stock options and RSUs recognized, before taxes, during the years ended December 31, 2022 and 2021, is as follows (in thousands):

	Year Ended December 31,
	2022		2021
Cost of revenues	$	18	$	101
Research and development expenses		37		287
Selling, general and administrative expenses		72		627
	$	127	$	1,015