8. Stock-Based Compensation

2016 Employee, Director and Consultant Equity Incentive Plan

The Company’s 2016 Employee, Director and Consultant Equity Incentive Plan, as amended (the “2016 Plan”), provides for the Company to sell or award restricted common stock or to grant incentive and nonqualified stock options for the purchase of common stock (or other stock-based awards) to its founders, employees, officers, directors and consultants.

As of December 31, 2025, 10,826,224 shares of common stock were authorized and reserved for issuance under the 2016 Plan. The remaining shares reserved for issuance under the 2016 Plan ceased to be available for issuance at the time the January 2026 Plan was adopted. There will be no further awards granted under the 2016 Plan, but all outstanding awards under the 2016 Plan will continue to be governed by the 2016 Plan.

2026 Stock Option and Grant Plan

On January 6, 2026, the Board of Directors adopted and the Company’s stockholders approved the 2026 Stock Option and Grant Plan (the “January 2026 Plan”). The January 2026 Plan provides for the grant of incentive stock options, nonqualified stock options, restricted stock awards and other stock-based awards to the Company’s officers, employees, directors, consultants, and other key persons.

The number of shares of common stock authorized and reserved for issuance under the January 2026 Plan was initially 8,873,223 shares. The remaining shares reserved for issuance under the January 2026 Plan ceased to be available for issuance at the time the 2026 Plan became effective. There will be no further awards granted under the January 2026 Plan, but all outstanding awards under the January 2026 Plan will continue to be governed by the January 2026 Plan.

2026 Stock Option and Incentive Plan

In May 2026, the Board of Directors adopted, and in June 2026 the Company’s stockholders approved, the 2026 Stock Option and Incentive Plan (the “2026 Plan”), which became effective in June 2026. The 2026 Plan provides for the grant of incentive stock options, nonqualified stock options, restricted stock units and other stock-based awards to the Company’s officers, employees, directors and consultants.

The number of shares of common stock authorized and reserved for issuance under the 2026 Plan was initially 11,070,000 shares. The 2026 Plan provides that the number of shares reserved and available for issuance under the 2026 Plan will automatically increase on January 1, 2027 and each January 1 thereafter during the term of the 2026 Plan, by (i) 5% of the sum of (A) the number of shares of common stock issued and outstanding on the immediately preceding December 31, (B) the number of shares underlying the Company's outstanding preferred stock (determined on an as-converted basis) on the immediately preceding December 31, and (C) the number of shares of common stock issuable pursuant to the exercise of any outstanding pre-funded warrants on the immediately preceding December 31, or (ii) such lesser number of shares as determined by the compensation committee of the Board of Directors.

The shares of common stock underlying any awards under the 2026 Plan, the January 2026 Plan and 2016 Plan that are forfeited, cancelled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, reacquired by the Company prior to vesting, satisfied without the issuance of stock, expire, or are otherwise terminated (other than by exercise) will be added back to the shares of common stock available for issuance under the 2026 Plan. As of June 30, 2026, there were 10,895,110 shares available for future issuance under the 2026 Plan.

Upon stock option exercise, the Company delivers newly issued shares to the participant. Stock option vesting typically occurs over four years for employees and directors and is at the discretion of the Board of Directors. Stock options typically have a maximum term of ten years.

2026 Employee Stock Purchase Plan

In May 2026, the Board of Directors adopted, and in June 2026 the Company’s stockholders approved, the 2026 Employee Stock Purchase Plan (the “ESPP”), which became effective in June 2026. A total of 1,110,000 shares of common stock were initially reserved for issuance under the ESPP. The ESPP provides that the number of shares reserved and available for issuance will automatically increase on January 1, 2027 and each January 1 thereafter through January 1, 2036, by the least of (i) 1,110,000 shares of common stock, (ii) 1% of the sum of (A) the number of shares of common stock issued and outstanding on the immediately preceding December 31, (B) the number of shares underlying the Company’s outstanding preferred stock (determined on an as-converted basis) on the immediately preceding December 31, and (C) the number of shares of common stock issuable pursuant to the

exercise of any outstanding pre-funded warrants on the immediately preceding December 31, or (iii) such lesser number of shares of common stock as determined by the administrator of the ESPP. As of June 30, 2026, there were 1,110,000 shares available for future issuance under the ESPP.

Stock Option Valuation

The weighted-average grant date fair values of stock options granted during the six months ended June 30, 2026 and 2025 were $2.92 and $1.89 per share, respectively. The intrinsic values of stock options exercised were $2.5 million and less than $0.1 million during the six months ended June 30, 2026 and 2025, respectively.

Total unrecognized compensation expense related to unvested stock options was approximately $22.3 million as of June 30, 2026, which the Company expects to recognize over a weighted-average period of approximately 3.1 years.

Total unrecognized compensation expense related to unvested stock options with a market condition was approximately $0.2 million as of June 30, 2026, which the Company expects to recognize over a weighted-average period of approximately 0.7 years.

In May 2026, the Company entered into an advisory agreement with a former member of its Board of Directors following the individual’s resignation. Pursuant to the agreement, the Company granted the former board member an option to purchase 71,479 shares of common stock and provided for the continued vesting and exercisability of existing stock option awards. The Company concluded that the advisory services are not substantive for accounting purposes and recognized $1.1 million of stock-based compensation expense, representing the grant-date fair value of the new award, and $0.5 million related to the modification of the existing awards. The amounts are included in general and administrative expenses in the condensed consolidated statements of operations and comprehensive loss during the three and six months ended June 30, 2026.

Stock-Based Compensation Expense