10. Equity-Based Compensation

2018 Stock Option and Grant Plan

In November 2018, the Company adopted, and its stockholders approved, the 2018 Stock Option and Grant Plan (the “2018 Plan”), which provides for the granting of stock options and other equity-based awards at the discretion of the Board of Directors or any subcommittee of the Board of Directors to the Company’s employees, officers, directors, and independent contractors. No further grants will be made under the 2018 Plan. However, the 2018 Plan will continue to govern outstanding equity awards granted thereunder. To the extent outstanding options granted under the 2018 Plan are cancelled, forfeited or otherwise terminated without being exercised and would otherwise have been returned to the share reserve under the 2018 Plan, the number of shares underlying such awards will be available for future grant under the 2020 Stock Option and Incentive Plan.

2020 Stock Option and Incentive Plan

In August 2020, the Company and its stockholders approved the 2020 Stock Option and Incentive Plan (the “2020 Plan”), which became effective on August 20, 2020. The 2020 Plan replaced the 2018 Plan as the Company’s Board of Directors has determined not to make additional awards under the 2018 Plan following the closing of the Company’s IPO. The 2020 Plan allows the Company to make equity-based and cash-based incentive awards to its officers, employees, directors and consultants. The Company initially reserved 4,457,370 shares of its common stock for the issuance of awards under the 2020 Plan, which includes the shares of common stock remaining available for issuance under its 2018 Plan as of the business day immediately prior to the effective date of the registration statement. The 2020 Plan provides that the number of shares reserved and available for issuance will automatically increase on January 1, 2021 and each January 1 thereafter, by 4% of the Company’s outstanding number of shares of common stock on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s compensation committee. These limits are subject to adjustment in the event of a stock split, stock dividend or other change in the Company’s capitalization. In June 2024, in connection with the Company's 2024 annual shareholder meeting, shareholders approved an amendment to the 2020 stock option plan that redefined the definition of common stock outstanding for the purposes of calculating the annual increase to the shares available for issuance. After the amendment, outstanding equity includes all outstanding common shares as well as outstanding pre-funded warrants. As of March 31, 2026, there were an aggregate of 6,667,087 shares remaining available for future grants.

2020 Employee Stock Purchase Plan

In August 2020, the Company and its stockholders approved the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), which became effective August 20, 2020. The 2020 ESPP initially reserved and authorized the issuance of up to a total of 445,653 shares of common stock to participating employees. The 2020 ESPP provides that the number of shares reserved and available for issuance will automatically increase on January 1, 2021 and each January 1 thereafter through January 1, 2030, by the lesser of (i) 438,898 shares of common stock, (ii) 1% of the Company’s outstanding number of shares of common stock on the immediately preceding December 31 or (iii) such lesser number of shares of common stock as determined by the administrator of the 2020 ESPP. The number of shares reserved under the 2020 ESPP is subject to adjustment in the event of a stock split, stock dividend or other change in the Company’s capitalization. As of March 31, 2026, there were an aggregate 2,742,310 shares remaining available for future grants.

Stock Options

The intrinsic value of stock options exercised during the three months ended March 31, 2026 and 2025 was $33.3 million and $2.1 million, respectively.

The weighted-average fair value of options granted during the three months ended March 31, 2026 and 2025 was $62.98 and $20.66, respectively.

As of March 31, 2026, the total unrecognized stock-based compensation expense for unvested stock options was $116.2 million, with a weighted average recognition period of 3.8 years.

Performance Stock Options

2025 Performance Stock Options

During the first quarter of 2025, the Company began granting performance stock options, or PSOs, under the Company’s 2020 Stock Option and Incentive Plan to certain key employees of the Company, including the Company’s executive officers and management team. The total number of PSOs that may vest will range from 0 to a maximum of 100% of the target number of options granted. The PSOs will vest in three separate installments based upon the achievement of three clinical milestones. The achievement of one clinical milestone will result in the vesting of 40% of the target amount, the achievement of a second clinical milestone will result in the vesting of 40% of the Target Amount and the achievement of the third clinical milestones will result in the vesting of 20% of the target amount. None of the PSOs with respect to the clinical milestone objective may vest prior to the first anniversary of the grant date. During the three months ended March 31, 2025, the Company granted 88,000 PSOs in relation to the 2025 PSO Grant with a weighted average strike price of $30.17. As of March 31, 2026 there are 88,000 PSOs outstanding with a weighted average strike price of $30.17 outstanding. As of March 31, 2026 the Company has concluded that it is not deemed probable that the clinical milestone based performance conditions will be achieved, and as such, no equity-based compensation has been recorded for PSOs.

2026 Performance Stock Options

During the first quarter of 2026, the Company granted 95,000 PSOs to certain key employees. The total number of PSOs that may vest will range from 0 to a maximum of 100% of the target number of options granted. The PSOs will vest in three separate installments subject to the achievement of two clinical milestones, and a third condition around relative Total Shareholder Return (“TSR”) of the Company’s Common Stock. Specifically, the achievement of the first clinical milestone will result in the vesting of 60% of the target amount, and the achievement of the second clinical milestone will result in the vesting of 15% of the target amount. None of the PSOs with respect to the clinical milestone objective may vest prior to the first anniversary of the grant date. As of March 31, 2026, the Company has concluded that it is not deemed probable that the clinical milestone based performance conditions for the 2026 PSOs will be achieved, and as such, no equity-based compensation has been recorded for clinical milestone portion of the 2026 PSOs.

25% of target PSOs earned will be based on the relative TSR of the Company’s common stock as compared to the TSR of the members of the S&P Biotechnology Select Industry Index ("XBI") over a three-year performance period from January 1, 2026 to December 31, 2028. Depending on the results relative to the TSR market condition, the holders may earn from 0% to 200% of the target amount of shares which will vest at the end of the performance period.

The PSOs will be forfeited if the performance conditions are not achieved at the end of the relative performance periods as described above. The vesting of the PSOs can also be triggered upon certain change in control events. The weighted-average grant date fair values of the PSOs relating to the TSR component were $97.53 per share. Stock-based compensation expense recognized for the PSOs relating to the TSR components were approximately $0.1 million and $0 for the three months ended March 31, 2026 and 2025, respectively. The measurement period for the TSR portion of the 2026 PSOs have not been met, and as such no shares have become exercisable. The Company estimated the fair values of shares granted under the market-based TSR PSOs using a Monte Carlo simulation model with the following assumptions:

Restricted Stock Units

2025 Performance Stock Units

During the first quarter of 2025, the Company began granting restricted stocks units with performance-based vesting conditions, or performance stock units ("PSUs") under the Company’s 2020 Stock Option and Incentive Plan to certain key employees of the Company, including the Company’s named executive officers and management team. Specifically, in the three months ended March 31, 2025, the Company granted 285,723 PSUs. The total number of PSUs that may vest will range from 0 to a maximum of 100% of the target number of units granted. The 2025 PSUs will vest in three separate installments based upon the achievement of three clinical milestones. The achievement of one clinical milestone will result in the vesting of 40% of the Target Amount, the achievement of a second clinical milestone will result in the vesting of 40% of the Target Amount and the achievement of third clinical milestones will result in the vesting of 20% of the Target Amount. None of the PSUs with respect to the clinical milestone objective may vest prior to the first anniversary of the grant date. As of March 31, 2026 the Company has concluded that it is not deemed probable that the clinical milestone based performance conditions for the 2025 PSUs will be achieved, and as such, no equity-based compensation has been recorded for the 2025 PSUs.

2026 Performance Stock Units

During the first quarter of 2026, the Company granted PSUs to certain key employees. The total number of PSUs that may vest will range from 0 to a maximum of 100% of the target number of units granted. The PSUs will vest in three separate installments subject to the achievement of two clinical milestones, and a third condition around relative TSR of the Company’s Common Stock. Specifically, the achievement of the first clinical milestone will result in the vesting of 60% of the target amount, and the achievement of the second clinical milestone will result in the vesting of 15% of the target amount. None of the PSUs with respect to the clinical milestone objective may vest prior to the first anniversary of the grant date. As of March 31, 2026, the Company has concluded that it is not deemed probable that the clinical milestone based performance conditions for the 2026 PSUs will be achieved, and as such, no equity-based compensation has been recorded for clinical milestone portion of the 2026 PSUs.

25% of target PSUs earned will be based on the relative TSR of the Company’s common stock as compared to the TSR of the members of the XBI over a three-year performance period from January 1, 2026 to December 31, 2028. Depending on the results relative to the TSR market condition, the holders may earn from 0% to 200% of the target amount of shares which will vest at the end of the performance period. The PSUs will be forfeited if the performance conditions are not achieved at the end of the relative performance periods as described above. The vesting of the PSUs can also be triggered upon certain change in control events. The weighted-average grant date fair values of the PSUs relating to the TSR component was $126.09 per share. Stock-based compensation expense recognized for the PSUs relating to the TSR component was approximately $0.1 million for the three months ended March 31, 2026. The measurement period for the TSR portion of the 2026 PSUs has not been met, and as such no shares have become exercisable. The Company estimated the fair values of shares granted under the market-based TSR PSUs using a Monte Carlo simulation model with the following assumptions:

During the three months ended March 31, 2026, the Company granted 344,242 and 73,672 restricted stock units with service and performance based vesting conditions respectively. During the three months ended March 31, 2025, the Company granted 327,800 and 285,723 restricted stock units with service and performance based vesting conditions respectively. As of March 31, 2026, the total unrecognized stock-based compensation expense for unvested restricted stock with service based vesting conditions was $54.1 million with a weighted average recognition period of 3.2 years. As of March 31, 2026, the total unrecognized stock-based compensation expense for unvested restricted stock with performance based vesting conditions was $2.3 million with a weighted average recognition period of 2.8 years.

During the three months ended March 31, 2026 the Company recognized approximately $3.8 million of expense for restricted stock which $2.7 million and $1.1 million was recorded in research and development and general and administrative expense, respectively. During the three months ended March 31, 2025 the Company recognized approximately $2.4 million of expense for restricted stock of which $1.6 million and $0.8 million was recorded in research and development and general and administrative expense, respectively.

Equity-Based Compensation Expense