During the three and nine months ended September 30, 2022 and 2021, the Company continued to administer and grant awards under the 2016 Incentive Award Plan, as amended (the “2016 Plan”), the Company’s only active equity incentive plan. Certain of the Company’s stock options granted under the Company’s 2008 Stock Plan (the “2008 Plan”), which is the predecessor to the 2016 Plan and became inactive upon adoption of the 2016 Plan effective September 20, 2016, remain outstanding and exercisable.

The Company accounts for restricted stock units (“RSUs”) based on their estimated fair values on the date of grant. The fair value of RSUs is estimated based on the closing price of the underlying common stock on the date of grant. Stock-based compensation expense related to the RSUs is recognized on a straight-line basis over the requisite service period, net of estimated forfeitures.

The terms of the RSUs, including the vesting provisions, are determined by the board of directors. Each RSU represents the contingent right to receive one share of common stock of the Company. The RSUs granted typically cliff vest after a one-year period for grants to directors and a two-year period for grants to employees, provided that the grantee remains a director, employee or consultant of the Company as of such vesting date.

For the three and nine months ended September 30, 2022, 50,500 and 476,606 RSUs were granted to directors and employees, respectively. There were no RSU grants for the three and nine months ended September 30, 2021.

The Company has occasionally used stock appreciation rights (“SARs”) as a component of executive compensation. As of December 17, 2019, the Company entered into an amended and restated employment agreement with Paula Brown Stafford which provided for a grant of 60,000 SARs with an exercise price of $8.20 per share (the fair market value of the Company’s common stock on the grant date) and with a ten year term. These SAR awards were vested in full as of December 31, 2021.

On August 2, 2018, the Company’s board of directors approved and established the Tangible Stockholder Return Plan, which was a performance-based long-term incentive plan (the “Performance Plan”). The Performance Plan was effective immediately upon approval and expired on March 1, 2022. The Performance Plan covered all employees, including the Company’s executive officers, consultants and other persons deemed eligible by the Company’s compensation committee. The core underlying metric of the Performance Plan was the potential achievement of two share price goals for the Company’s common stock, which, if achieved, could have represented measurable increases in stockholder value.

The Performance Plan expired on March 1, 2022. As the Company’s stock price did not reach the minimum share price targets necessary to trigger a payment, no payments were made under the Performance Plan to any participants during the period the Performance Plan was effective.


	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Stock options	$	283	$	298	$	1,029	$	491
Restricted stock units	226		—		314		—
Stock appreciation rights	—		29		—		87
Tangible Stockholder Return Plan	—		(150)		—		(662)
Total	$	509	$	177	$	1,343	$	(84)

Total stock-based compensation expense included in the accompanying condensed consolidated statements of operations and comprehensive loss is as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	127	$	(13)	$	320	$	(325)
Selling, general and administrative	382		190		1,023		241
Total	$	509	$	177	$	1,343	$	(84)


	Shares Subject to Outstanding Options	Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Options outstanding as of December 31, 2021	518,553	$	15.48
Options granted	543,300	3.25
Options forfeited	(15,850)	6.50

Options outstanding as of September 30, 2022	1,046,003	$	9.26	8.74	$	—


	Shares Subject to Outstanding RSUs	Weighted- Average Grant Date Fair Value
Nonvested RSUs outstanding as of December 31, 2021	—	$	—
RSUs granted	476,606	2.88
RSUs forfeited	(12,400)	2.98
RSUs vested	—	—
Nonvested RSUs outstanding as of September 30, 2022	464,206	$	2.88