PepGen Inc.

Director and Executive Officer Trading Arrangements

During the fourth quarter of 2025, none of our directors or officers adopted orterminated any contract, instruction or written plan for the purchase or sale of our securities intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act or any “non-Rule 10b5-1 trading arrangement” (as defined in Item 408(c) of Regulation S-K).

Amended and Restated Employment Agreements

On March 3, 2026, we entered into an amended and restated employment agreement with each of James McArthur (the “McArthur Employment Agreement”), Noel Donnelly (the “Donnelly Employment Agreement”), and Paul Streck (the “Streck Employment Agreement” and collectively, the “Amended Employment Agreements”). Pursuant to each of the Amended Employment Agreements, the definition of Sale Event Period was updated to include the three-month period prior to an event constituting a Sale Event (as defined in each of the Amended Employment Agreements) in addition to the 12-month period after such Sale Event. Each of the Amended Employment Agreements replace and supersede all prior employment agreements between the Company and each of Dr. McArthur, Mr. Donnelly, and Dr. Streck.

The foregoing description of each of the McArthur Employment Agreement, Donnelly Employment Agreement, and Streck Employment Agreement does not purport to be complete and is qualified in its entirety by reference to the complete text of each of McArthur Employment Agreement, Donnelly Employment Agreement, and Streck Employment Agreement, which will be filed as exhibits to the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2026.