9. Stock-Based Compensation

Equity Plans

On July 2, 2014, the stockholders of the Company approved the 2014 Stock Option and Incentive Plan (the “2014 Plan”), which became effective immediately prior to the completion of the Company’s initial public offering. The 2014 Plan provided for the grant of restricted stock awards, restricted stock units, incentive stock options and non-statutory stock options. The 2014 Plan replaced the Company’s 2011 Stock Option and Grant Plan (the “2011 Plan”).

On June 10, 2024, the stockholders of the Company approved the 2024 Equity Incentive Plan (the “2024 Plan”), which had been previously approved by the Board. Upon stockholder approval, the 2024 Plan became effective immediately and replaced the 2014 Plan. The 2024 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, other stock-based awards, and cash awards. The total number of shares initially reserved for issuance under the 2024 Plan is equal to the sum of (i) 5,500,000 shares of the Company’s common stock and (ii) such additional number of shares of the Company’s common stock (up to 11,002,166 shares) as is equal to the number of shares of common stock subject to awards granted under the 2014 Plan that were outstanding as of June 10, 2024, and which awards expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right (subject, however, in the case of incentive stock options, to any limitations under the Internal Revenue Code of 1986, as amended, and any regulations thereunder).

The Company no longer grants stock options or other awards under either its 2014 Plan or its 2011 Plan, and there are no stock options or other awards outstanding under the 2011 Plan. Any stock options and other awards outstanding under the 2014 Plan remain outstanding and effective in accordance with their terms.

On December 15, 2016, the Board approved the 2016 Inducement Equity Plan (as amended and restated, the “2016 Plan”). The 2016 Plan provides for the grant of equity awards to individuals who have not previously been an employee or a non-employee director of the Company to induce them to accept employment and to provide them with a proprietary interest in the Company. On September 20, 2018, the Board amended the 2016 Plan to increase the total number of shares reserved for issuance by 1,200,000 shares. On April 16, 2024, the Board amended the 2016 Plan to reduce the number of shares reserved for issuance thereunder to 428,074 shares and provide that no further grants may be made under the 2016 Plan after April 16, 2024.

Terms of equity grants, including vesting requirements, are determined by the Board or the Compensation Committee of the Board, subject to the provisions of the applicable plan. Stock options granted by the Company that are not performance-based are considered time-based because they vest based on the continued service of the grantee with the Company during a specified period following grant. These awards, when granted to employees, generally vest ratably over four years, with 25% vesting at the one-year anniversary, and generally expire 10 years after the date of grant.

As of June 30, 2025, the total number of shares underlying outstanding awards under the 2024 Plan, the 2014 Plan, and the 2016 Plan was 8,652,872, and the total number of shares available for future issuance under the 2024 Plan was 6,247,443 shares.

On June 16, 2022, the Company’s stockholders approved an amendment to the amended 2014 Employee Stock Purchase Plan (the “ESPP”), which had been previously approved by the Board, to add 300,000 shares of common stock to the ESPP. On June 15, 2023, the Company’s stockholders approved another amendment to the ESPP, which had been previously approved by the Board, to add an additional 500,000 shares of common stock to the ESPP. On June 11, 2025, the Company’s stockholders approved another amendment to the ESPP, which had been previously approved by the Board, to add an additional 500,000 shares of common stock to the ESPP. As amended, a total of 1,582,000 shares of common stock have been authorized for issuance under the ESPP. As of June 30, 2025, 715,242 shares have been issued and 866,758 shares are available for future issuance under the ESPP. Under the terms of the

Merger Agreement, all offering periods under the ESPP following June 30, 2025, are suspended unless and until the Merger Agreement is terminated.

Option Exchange Program

On January 23, 2024, the Company initiated a tender offer related to a one-time stock option exchange program pursuant to which eligible non-executive officer employees were given the opportunity to exchange certain outstanding stock options (the “Eligible Options”) to purchase shares of the Company’s common stock for replacement options to purchase a lesser number of shares of common stock (the “Option Exchange”) upon the terms and subject to the conditions set forth in the Offer to Exchange Eligible Options for Replacement Options dated January 23, 2024 (the “Offer to Exchange”). Stock options eligible for exchange had an exercise price per share of $35.00 or greater, in addition to certain other requirements, and were exchanged for replacement options with an exercise price per share equal to the fair market value of the Company’s common stock on the date of grant of the replacement options, which was February 21, 2024. The consummation of the Option Exchange was subject to approval by the Company’s stockholders, which approval was received at the special meeting of stockholders held on January 31, 2024. The Company accepted for exchange Eligible Options to purchase a total of 3,079,608 shares of the Company’s common stock. All tendered Eligible Options were cancelled effective as of February 21, 2024, and promptly thereafter, in exchange thereof, the Company granted replacement options for a total of 1,483,113 shares of the Company’s common stock, pursuant to the terms of the Offer to Exchange and the 2014 Plan. The exercise price per share of the replacement options was $22.20 per share, which was the closing price per share of the Company’s common stock on the Nasdaq Global Market on February 21, 2024. The replacement options vest over 18 months from the date of grant and have a term of seven years.

The Company expects to incur a total of $1.7 million of additional stock-based compensation expense as a result of the Option Exchange, to be recognized over the 18-month vesting period of the replacement options.

Restricted Stock Units

Time-based restricted stock units

During the three and six months ended June 30, 2025, the Company granted 82,840 and 1,576,292 time-based restricted stock units, respectively, to its employees.

During the three and six months ended June 30, 2024, the Company granted 24,941 and 882,025 time-based restricted stock units, respectively, to its employees.

During the three and six months ended June 30, 2025, there were 9,430 and 1,154,333 time-based restricted stock units that vested, respectively. The fair value on the date of vesting for the three and six months ended June 30, 2025, was $0.1 million and $8.5 million, respectively.

During the three and six months ended June 30, 2024, there were 10,096 and 80,039 time-based restricted stock units that vested, respectively. The fair value on the date of vesting for the three and six months ended June 30, 2024, was $0.1 million and $1.7 million, respectively.

At June 30, 2025, 1,916,330 time-based restricted stock units were both outstanding and unvested, and the total unrecognized stock-based compensation expense related to these awards was $14.2 million, which is expected to be recognized over the remaining weighted average vesting period of 3.36 years.

Performance restricted stock units

During the three and six months ended June 30, 2025, the Company granted 6,000 and 418,000 performance restricted stock units, respectively, to its employees.

During the six months ended June 30, 2024, the Company granted 395,055 performance restricted stock units to its employees. During the three months ended June 30, 2024, the Company did not grant any performance restricted stock units.

The majority of the performance restricted stock units vest upon the achievement of certain clinical and regulatory development milestones related to product candidates and certain commercial milestones. Certain performance restricted stock units vest upon the Company reaching specified measures of total stockholder return.

Recognition of stock-based compensation expense associated with performance restricted stock units, except for those with milestones that are measures of total stockholder return, commences when the performance condition is considered probable of achievement, using management’s best estimates, which consider the inherent risk and uncertainty regarding the future outcomes of the milestones. Recognition of stock-based compensation expense associated with performance restricted stock units with milestones that are measures of total stockholder return commences on the grant date and is recorded independently of the vesting outcomes of the grants.

During the three months ended June 30, 2025, the criteria for one vesting milestone for outstanding performance restricted stock units was met. The fair value of the 87,357 shares on the date of vesting was $0.6 million.

As of June 30, 2025, the criteria for one vesting milestone for outstanding performance restricted stock units was considered probable. The Company recognized stock-based compensation expense related to the probable vesting of this performance restricted stock unit of $2.9 million during the three months ended June 30, 2025. As of June 30, 2025, $0.2 million of expense remains to be recognized.

No performance restricted stock units vested during the three and six months ended June 30, 2024.

During the three and six months ended June 30, 2025, the Company recorded $0.5 million and $0.7 million, respectively, of stock-based compensation expense, related to performance restricted stock units for which vesting is tied to total stockholder return.

During the three and six months ended June 30, 2024, the Company recorded $0.4 million and $0.8 million, respectively, of stock-based compensation expense, related to performance restricted stock units for which vesting is tied to total stockholder return.

As of June 30, 2025, 1,174,141 performance restricted stock units were both outstanding and unvested, and the total unrecognized stock-based compensation expense related to these awards was $30.2 million.

Stock Option Rollforward

As of June 30, 2025, the Company had unrecognized stock-based compensation expense related to its outstanding and unvested time-based stock option awards of $19.5 million, which is expected to be recognized over the remaining weighted average vesting period of 3.76 years.

There were no stock options exercised during the six months ended June 30, 2025. The intrinsic value of stock options exercised during the six months ended June 30, 2024 was $0.1 million.

Performance-Based Stock Options

Recognition of stock-based compensation expense associated with performance-based stock options commences when the performance condition is considered probable of achievement, using management’s best estimates, which consider the inherent risk and uncertainty regarding the future outcomes of the milestones.

As of June 30, 2025 and 2024, for performance-based stock option grants that were outstanding, the achievement of the milestones that had not been met was considered not probable, and therefore no expense has been recognized related to these awards during the three and six months ended June 30, 2025 and 2024, respectively.

During the three and six months ended June 30, 2025 and 2024, the Company granted no stock options to purchase shares of common stock that contain performance-based vesting criteria.

During the three and six months ended June 30, 2025 and 2024, no milestones were achieved under performance-based stock options.

As of June 30, 2025, 455,000 performance-based stock options were both outstanding and unvested, the total unrecognized stock-based compensation expense related to these awards was $24.9 million before the application of the forfeiture rate and the timing of recognition of this stock-based compensation expense is subject to judgment of the Company as to when the performance conditions are considered probable of being achieved.

Stock-Based Compensation Expense

For stock option awards, the fair value is estimated at the grant date using the Black-Scholes option-pricing model, taking into account the terms and conditions upon which stock options are granted. The fair value of the stock options is amortized on a straight-line basis for stock option awards to employees, non-employee directors and non-employee consultants over the requisite service period of the awards.

The weighted average grant date fair value per share of stock options granted under the Company’s stock option plans during the six months ended June 30, 2025 and 2024 was $4.81 and $14.69, respectively.