12. Stock-based Compensation

2025 Employment Inducement Award Plan

On February 3, 2025, the Company’s board of directors adopted the 2025 Employment Inducement Plan (the “Inducement Plan”) pursuant to which the Company reserved 500,000 shares of its common stock to be used exclusively for grants of awards to individuals who were not previously employees or directors, as an inducement material to the individual’s entry into employment with the Company within the meaning of Rule 5635(c)(4) of the Marketplace Rules of the Nasdaq Stock Market. The Inducement Plan provides for the grant of stock options, restricted stock units, and other stock-based awards. In January 2026, the Company's board of directors adopted an amendment to the Inducement Plan to reserve an additional 1,000,000 shares of common stock under the Inducement Plan. As of June 30, 2026, there were 872,350 shares available for future grants under the Inducement Plan.

2020 Incentive Award Plan

In December 2020, the Company adopted the 2020 Incentive Award Plan (“2020 Plan”), which became effective on December 10, 2020. The 2020 Plan initially reserved 2,606,546 shares of common stock for the issuance of stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance bonus awards, performance stock units, dividend equivalents or other stock or cash based award granted to employees, directors and consultants of the Company. The number of shares reserved for future issuance under the 2020 Plan will increase annually on the first day of each fiscal year beginning in 2021 and ending in 2030 by the lesser of (i) 5% of the shares of common stock outstanding (on an as converted basis) on the last day of the immediately preceding fiscal year and (ii) such number of shares of common stock as determined by the Company's board of directors, provided, however, no more than 18,000,000 shares of the Company’s common stock may be issued upon the exercise of incentive stock options. As a result of the operation of the automatic annual increase provision of the 2020 Plan, an additional 2,289,625 shares of common stock became available for issuance on February 28, 2025 and an additional 2,880,394 shares of common stock became available for issuance on March 18, 2026 under the 2020 Plan. All stock options are exercisable over a period not to exceed the contractual term of ten years from the date the stock options were issued. As of June 30, 2026, there were 1,735,472 shares available for grant under the 2020 Plan.

Following the effectiveness of the 2020 Plan, the Company will not make any further grants under the 2015 Equity Incentive Plan (the “2015 Plan”). However, the 2015 Plan continues to govern the terms of stock options that remain outstanding under the 2015 Plan.

2015 Equity Incentive Plan

The 2015 Plan provided for grants of stock options, stock appreciation rights, restricted stock and restricted stock unit awards to employees, directors and consultants of the Company. As of June 30, 2026, stock options to purchase 1,112,990 shares of common stock were outstanding under the 2015 Plan. All stock options are exercisable over a period not to exceed the contractual term of ten years from the date the stock options were issued and are granted at prices not less than the estimated fair market value of the Company’s common stock on the grant date as determined by the board of directors.

No additional grants will be made under the 2015 Plan, and all outstanding grants under the 2015 Plan that are repurchased, forfeited, expire or are cancelled are returned to the 2015 Plan and are not available for grant under the 2020 Plan.

Employee Stock Purchase Plan

In December 2020, the Company adopted the 2020 Employee Stock Purchase Plan (the “2020 ESPP”). Under the 2020 ESPP, 252,337 shares of the Company’s common stock were initially reserved for employee purchases of the Company’s common stock under terms and provisions established by the Company’s board of directors and approved by the Company’s stockholders. The number of shares reserved for future issuance under the 2020 ESPP will increase annually on the first day of each fiscal year beginning in 2021 and ending in 2030 by the lesser of (i) 1% of the shares of common stock outstanding (on an as converted basis) on the last day of the immediately preceding fiscal year and (ii) such number of shares of common stock as determined by the Company’s board of directors, provided, however, no more than 15,000,000 shares of the Company’s common stock may be issued under the 2020 ESPP. As a result of the operation of this annual increase provision of the 2020 ESPP, an additional 150,000 shares of common stock became available on February 28, 2025 and an additional 576,079 shares of common stock became available for issuance on March 18, 2026 under the 2020 ESPP.

Under the 2020 ESPP, the Company’s employees may purchase common stock through payroll deductions at a price equal to 85% of the lower of the fair market value of the stock at the beginning of the offering period or at the end of each applicable purchase period. The 2020 ESPP provides for a series of overlapping 24-month offering periods comprising four six-month purchase periods. Contributions under the 2020 ESPP are limited to a maximum of 15% of an employee’s eligible compensation.

Restricted Stock Units

The Company has granted restricted stock unit (RSU) awards under the 2020 Incentive Award Plan that vest over a period of four years. The following table summarizes the RSU activity:

Stock Options

The Company estimates the fair value of stock options using the Black-Scholes option pricing model. The fair value of employee and nonemployee stock options is recognized on a straight-line basis over the requisite service period of the awards. The fair value of the Company’s stock options was estimated using the following assumptions:

Expected Term. The expected term for employee stock options is calculated using the simplified method as the Company does not have sufficient historical information to provide a basis for this estimate. The simplified method is based on the average of the vesting tranches and the contractual life of each grant. The expected term for nonemployee stock options is the contractual term of the stock options.

Expected Volatility. The expected volatility is based on a mix of the Company’s historical volatility and the historical volatility of comparable companies with similar attributes to the Company, including industry, stage of life cycle, size and financial leverage. For each grant, the Company measured historical volatility over a period equivalent to the expected term.

Risk-free Interest Rate. The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues whose term is similar in duration to the expected term of the respective stock option.

Expected Dividend Yield. The Company has not paid and does not anticipate paying any dividends on its common stock in the future. Accordingly, the Company has estimated the dividend yield to be zero percent.

Stock-Based Compensation Expense