Practices Related to the Grant of Certain Equity Awards

In accordance with Item 402(x) of Regulation S-K, we are providing information regarding our practices related to the grant of stock options close in time to the release of material non-public information. As described above, it is not our policy to time the release of material nonpublic information for the purpose of affecting the value of executive compensation or to take material nonpublic information into account when determining the timing and terms of such awards. Although we do not have a formal policy with respect to the timing of our annual equity award grants, our board of directors or compensation committee has historically granted such awards on a predetermined annual schedule, which includes annual equity awards approved during the first quarter and granted on the first business day of March of each year. Equity grants may also be made on other dates in connection with new hires, promotions, or similar events, and are typically made on the first business day of the month following the employees start date, unless a different date is approved by our compensation committee.

(1) The amounts reported represent the grant date fair value of options to purchase shares of our common stock, calculated in accordance with FASB ASC Topic 718. The assumptions used in calculating the grant date fair value of the awards reported in this column are set forth in the notes to our consolidated financial statements included in our 2025 Annual Report. The amounts reported in this column reflect the accounting cost for the options and do not correspond to the actual economic value that could be or may have been received upon exercise of the options or any sale of any of the underlying shares. Mr. Vittiglio joined PepGen in December 2025 and did not receive the 2025 annual equity award.

(2) With respect to amounts reported for Dr. McArthur and Mr. Donnelly, the amounts represent the percentage change in the closing price of our common stock between the trading day ending immediately prior to the disclosure of material nonpublic information (a closing price of $2.81 on March 3, 2025) and the trading day beginning immediately following the disclosure of material nonpublic information (a closing price of $2.63 on March 5, 2025). With respect to the amount reported for Mr. Vittiglio, the amount represents the percentage change in the closing price of our common stock between the trading day ending immediately prior to the disclosure of material nonpublic

information (a closing price of $5.59 on December 8, 2025) and the trading day beginning immediately following the disclosure of material nonpublic information (a closing price of $5.70 on December 9, 2025). We have assumed for purposes of this table that each of the respective Form 8-K filed with the SEC within four business days after the grants reported in the table as including material nonpublic information for purposes of this table.