11. Stock-Based Compensation

The 2020 Plan

The 2020 Plan was established for granting stock incentive awards to directors, officers, employees and consultants to the Company. On June 7, 2024, the stockholders of the Company approved an amendment to the 2020 Plan, pursuant to which the number of shares of common stock reserved and available for issuance under the 2020 Plan increased by 2,500,000 shares. On January 3, 2025, the stockholders of the Company approved an amendment to the 2020 Plan, pursuant to which the number of authorized shares of common stock reserved for issuance under the 2020 Plan increased by 27,453,993 shares. On June 27, 2025, the stockholders of the Company approved an amendment to the 2020 Plan, pursuant to which (i) the term of the 2020 Plan was extended by approximately five years to 2030, and (ii) an automatic evergreen provision was added to provide for an annual increase to the number of shares available for issuance under the 2020 Plan on January 1 of each year during the term of the plan, starting with January 1, 2026 to the lesser of (a) 4% of the total shares of the Company’s common stock outstanding on December 31 of the prior year (including, for this purpose, the number of shares underlying any pre-funded warrants) or (b) a lesser number of shares of the Company’s Common Stock determined by the administrator of the 2020 Plan. On January 1, 2026, the number of shares available for issuance under the 2020 Plan was increased by 6,969,206 shares pursuant to the evergreen provision.

On June 26, 2026, the stockholders of the Company approved an amendment to the 2020 Plan, pursuant to which the number of shares of common stock reserved and available for issuance under the 2020 Plan increased by 3,000,000 shares. Subject to certain adjustments, including the forfeiture of options previously granted under the Company's 2011 Equity Incentive Plan that are added back to the 2020 Plan, the maximum number of shares of common stock that may be issued under the 2020 Plan following the stockholders' approval on June 26, 2026 is limited to 41,386,723 shares.

The 2026 Inducement Plan

On March 25, 2026, the Company's board of directors approved the Inhibikase Therapeutics, Inc. 2026 Inducement Plan (the "Inducement Plan"), pursuant to which the Company reserved 4,000,000 shares of common stock for issuance exclusively pursuant to equity-based awards to individuals who were not previously employees or directors of the Company, as a material inducement to the individual’s entry into employment with the Company. The Inducement Plan provides for the grant of equity-based awards in the form of nonstatutory stock options, stock appreciation rights, restricted stock awards, and restricted stock unit awards. The Inducement Plan was adopted without stockholder approval in accordance with Nasdaq Listing Rule 5635(c)(4).

Restricted Stock

In connection with the acquisition of CorHepta in February 2025 (see Note 9), the Company issued a combined 1,660,222 shares of restricted common stock to two selling shareholders of CorHepta who were subsequently employed by the Company, which were subject to a combination of post-acquisition service- and performance-based vesting conditions, as follows: (i) 996,133 shares vested on the first anniversary of the closing of the acquisition, (ii) the remaining 664,089 shares were forfeited on February 21, 2026 as a result of the non-achievement of a certain milestone specified in the Merger Agreement. There was no restricted stock outstanding as of September 30, 2026.

For the restricted shares with service-based vesting conditions, stock-based compensation expense is recognized on a straight-line basis over the service period, which is generally the vesting term. For restricted shares with performance-based vesting conditions, stock-based compensation expense is recognized over the requisite service period when it is probable that the performance condition will be achieved.

The weighted-average grant date fair value of the restricted shares issued in connection with the asset acquisition was $4.9 million. During the three and nine months ended September 30, 2026, the Company recognized stock-based compensation expense of $0 and $0.4 million, respectively, related to the restricted shares with service-based vesting conditions. During the three and nine months ended September 30, 2025, the Company recognized stock-based compensation expense of $0.7 million and $1.8 million, respectively, related to the restricted shares with service-based vesting conditions. No stock-based compensation expense was recognized related to the restricted shares with performance-based vesting conditions during the three and nine months ended September 30, 2026 and 2025, as the performance conditions were not probable. As of September 30, 2026, there was $0 of unrecognized compensation expense related to the restricted shares issued in connection with the acquisition of CorHepta.

Stock Options

During the nine months ended September 30, 2026, the Company granted 13,667,142 options to purchase common stock with a weighted average exercise price of $1.99. These options vest either (i) one-fourth on the first anniversary of the grant of such option with the remainder to vest in 36 equal monthly installments thereafter, (ii) in 36 equal monthly installments, or (iii) on the first anniversary of the grant date. The aggregate grant date fair value of all options granted was $21.7 million.

During the nine months ended September 30, 2025, the Company granted 27,225,823 options to purchase common stock with a weighted average exercise price of $2.34. These options vest either (i) annually in three equal parts over three years, (ii) one-fourth on the first anniversary of the grant of such option with the remainder to vest in 36 equal monthly installments thereafter, (iii) in 48 equal monthly installments, (iv) annually over two years, (v) annually over four years, (vi) on the earlier of one year or the day prior to the annual meeting of stockholders, or (vii) in full on the date of grant. The Company also granted 2,056,049 performance-based options to purchase common stock with a weighted average exercise price of $2.35 to certain employees. These options will vest and become exercisable once the performance conditions are probable of being met. There is no assurance that the performance conditions will be met and therefore some or all of these options may never vest or become exercisable. The aggregate grant date fair value of all options granted was $54.7 million. During the nine months ended September 30, 2025, certain performance conditions were probable of being met.

For awards with performance conditions in which the award does not vest unless the performance condition is met, the Company recognizes expense if, and to the extent that, the Company estimates that achievement of the performance condition is probable. If the Company concludes that vesting is probable, the Company recognizes expense from the date the Company reaches this conclusion through the estimated vesting date.

As of September 30, 2026, the total compensation cost related to non-vested option awards not yet recognized was $49.2 million, with a weighted average remaining vesting period of 2.41 years.

Stock-Based Compensation Expense

* Includes $0 and $0.4 million for the three and nine months ended September 30, 2026, respectively, and $0.7 million and $1.8 million for the three and nine months ended September 30, 2025, respectively, related to the restricted stock awards issued in connection with the acquisition of CorHepta.