X0508 4 2025-11-04 0001835597 PepGen Inc. PEPG 0001922546 Donnelly Noel 321 HARRISON AVE., 8TH FLOOR C/O PEPGEN INC. BOSTON MA 02118 1 Chief Financial Officer 0 Stock Option (Right to Buy) 10.88 2025-11-04 4 D 0 203339 0 D 2031-11-10 Common Stock 203339 0 D Stock Option (Right to Buy) 4.53 2025-11-04 4 A 0 203339 0 A 2031-11-10 Common Stock 203339 203339 D Stock Option (Right to Buy) 12.00 2025-11-04 4 D 0 169037 0 D 2032-05-05 Common Stock 169037 0 D Stock Option (Right to Buy) 4.53 2025-11-04 4 A 0 169037 0 A 2032-05-05 Common Stock 169037 169037 D Stock Option (Right to Buy) 15.25 2025-11-04 4 D 0 144000 0 D 2033-02-28 Common Stock 144000 0 D Stock Option (Right to Buy) 4.53 2025-11-04 4 A 0 144000 0 A 2033-02-28 Common Stock 144000 144000 D Stock Option (Right to Buy) 16.62 2025-11-04 4 D 0 144000 0 D 2034-02-28 Common Stock 144000 0 D Stock Option (Right to Buy) 4.53 2025-11-04 4 A 0 144000 0 A 2034-02-28 Common Stock 144000 144000 D On November 4, 2025, the Issuer's Board of Directors approved a repricing of the Reporting Person's outstanding stock options granted under the Issuer's 2020 Stock Plan, 2022 Stock Option and Incentive Plan, and 2024 Inducement Plan. The exercise price of eligible options was reduced to $4.53, with all other terms unchanged except that the reduced exercise price is available only if the Reporting Person satisfies the applicable retention period; otherwise, the original exercise price will apply. The transactions reported herein are exempt pursuant to Rules 16b-6(d) and 16b-3 under the Securities Exchange Act of 1934. This stock option vests over four years following the vesting commencement date (October 15, 2021) with 25% of such shares vesting on the first anniversary of the vesting commencement date, and the remaining shares vesting in 36 equal monthly installments, subject to continued service through each vesting date. This option shall vest as follows: twenty-five percent (25%) on the one-year anniversary of the Grant Date and the remainder vesting in thirty-six (36) equal monthly installments, subject to the option recipient's continued service or employment with the Company on each applicable vesting date. /s/ Noel Donnelly, as attorney-in-fact 2025-12-18