Stock Based Compensation

3 Months Ended

Mar. 31, 2024

Stock Based Compensation [Abstract]

Stock Based Compensation

Note 5 — Stock-Based Compensation

Our stockholders approved the Amended and Restated 2013 Equity Incentive Plan (the “A&R Plan”) at our annual shareholders’ meeting in June 2023, which added 175,000 shares to the plan. Our prior plan expired March 29, 2023; no further awards will be made under the prior plan, but the A&R Plan will govern awards granted under the prior plan. The A&R Plan provides for the granting of stock options, restricted stock units (“RSUs”) and restricted stock. Options granted under the A&R Plan are granted with an exercise price equal to the fair value of the of our stock on the date of grant. RSUs and restricted stock are granted at the fair value of our stock on the date of grant because they have no exercise price. The fair value of options, RSUs and restricted stock are expensed over the vesting periods. All options, RSUs and restricted stock are subject to forfeiture if service terminates prior to the shares vesting. At March 31, 2024, there were 97,031 shares available for grant under the A&R Plan.

Stock-based compensation expense included in general and administrative expense was $230 and $371, and in research and development expense was $258 and $311, for the three months ended March 31, 2024 and 2023, respectively.

During the three months ended March 31, 2024, we granted 71,000 shares of restricted stock with a weighted average grant date fair value of $6.80. During the three months ended March 31, 2024, we paid $3 in withholding taxes on shares issued upon granting of restricted stock; the underlying shares were cancelled. The amounts are reflected as financing costs in the accompanying statement of cash flows. No restricted stock was issued during the three months ended March 31, 2023.

No options or RSUs were granted during the three months ended March 31, 2024 or 2023. No options were exercised during the three months ended March 31, 2024 or 2023, and no shares were issued as a result of vesting RSUs in the three months ended March 31, 2024 or 2023.

As of March 31, 2024 and 2023, the unrecognized stock-based compensation expense related to unvested stock options, RSUs, and restricted stock was $2,757 and $3,484, respectively, which will be amortized over an estimated weighted average period of approximately 2.63 years and 2.47 years, respectively.

During the three months ended March 31, 2024 we returned 24,750 options, 1,752 RSUs and 6,581 Restricted Stock to the plan due to termination of employees. During the three months ended March 31, 2023, we returned 2,000 options to the plan due to the 10-year expiration for unexercised options.