8. Equity Incentive Plan

RSUs

As part of the Company’s IPO, the Company adopted and approved the 2021 Incentive Award Plan, which has been subsequently amended and restated three times (as accordingly amended and restated, the “2021 Incentive Plan”). Under the 2021 Incentive Plan, the Company may grant cash and equity incentive awards to employees and eligible service providers in order to attract, motivate and retain the talent for which the Company competes.

RSUs are taxable upon vesting based on the market value on the date of vesting. The Company is required to make mandatory tax withholding for the payment and satisfaction of income tax, social security tax, payroll tax, or payment on account of other tax related to withholding obligations that arise by reason of vesting of an RSU. The taxable income is calculated by multiplying the number of vested RSUs for each individual by the closing share price as of the vesting date and a tax liability is calculated based on each individual’s tax bracket. During the three months ended March 31, 2026, a total of 332,514 RSUs vested for Class A common stock shares. Of that amount, the Company withheld 160,486 Class A common stock shares to satisfy employee tax liabilities. During the year ended December 31, 2025, a total of 655,922 RSUs vested for Class A common stock shares. Of that amount, the Company withheld 260,007 Class A common stock shares to satisfy employee tax liabilities. The shares withheld are available for reissuance pursuant to the Company’s 2021 Incentive Plan. Each RSU grant made during the three months ended March 31, 2026 and during 2025 was expensed ratably over its respective vesting period, with prorated adjustments made as needed to align with grant dates and the applicable service periods.

As of March 31, 2026 and December 31, 2025, the Company had 1,135,034 and 1,209,738, respectively, RSUs outstanding (unvested).

Stock Options

Stock options may be granted under the 2021 Incentive Plan. The exercise price of options is equal to the fair market value of the Company’s Class A common stock as of the grant date. Options historically granted have generally become exercisable over three or four years and expire ten years from the date of grant.

The fair value of the stock options issued during three months ended March 31, 2026 were estimated using the Black-Scholes option-pricing model and had the following assumptions: a dividend yield of 0%; an expected life of 6 years; volatility of 90%; and risk-free interest rate based on the grant date of 3.8%.

During the three months ended March 31, 2025, the Company entered into a stock option agreement with the CSO. The issuance of the option was contingent on stockholder approval to an increase in the number of shares available for awards under the Company's 2021 Incentive Plan at the 2025 Annual Meeting of Stockholders held on June 13, 2025. This option vested in full on July 1, 2025.

Each option grant is being expensed ratably over the option vesting periods, with prorated adjustments made as needed to align with grant dates and applicable service period.

As of March 31, 2026, the Company has recorded issued and outstanding options to purchase a total of 837,887 shares of Class A common stock pursuant to the 2021 Incentive Plan, at a weighted average exercise price of $2.61 per share. Also, as of December 31, 2025, the Company has recorded issued and outstanding options to purchase a total of 658,187 shares of Class A common stock pursuant to the 2021 Incentive Plan, at a weighted average exercise price of $3.18 per share.

For the three months ended March 31, 2026 and 2025, equity-based compensation expense amounted to approximately $0.4 million and $0.3 million, respectively, which is included in the research and development and general and administrative expenses in the condensed statements of operations.

As of March 31, 2026, the remaining unrecognized RSUs compensation of approximately $1.4 million will be recognized over approximately 2.0 years. The remaining unrecognized stock options compensation of approximately $0.4 million will be recognized over approximately 2.4 years.