SCHEDULE 13G/A 0001493215 XXXXXXXX LIVE 1 Common Stock, $0.0001 par value per share 03/31/2025 0001835597 PepGen Inc. 713317105 321 Harrison Avenue 8th Floor Boston MA 02118 Rule 13d-1(b) RTW Investments, LP DE 0 0 0 0 0 N 0.0 PN IA Roderick Wong, M.D. X1 0 0 0 0 0 N 0.0 IN HC PepGen Inc. 321 Harrison Avenue, 8th Floor, Boston, MA 02118 This statement is filed by: (i) RTW Investments, LP ("RTW Investments"), a Delaware limited partnership and the investment adviser to certain funds (the "RTW Funds"), with respect to shares of Common Stock, par value $0.0001 per share (the "Shares") of PepGen Inc. (the "Company") that were directly held by the RTW Funds; and (ii) Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares that were directly held by the RTW Funds. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The address of the business office of each of the Reporting Persons is 40 10th Avenue, Floor 7, New York, New York 10014. RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States. N IA HC The information required by Item 4(a) is set forth in Rows 5 - 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. RTW Investments: 0.0% Dr. Wong: 0.0 RTW Investments: 0 Dr. Wong: 0 RTW Investments: 0 Dr. Wong: 0 RTW Investments: 0 Dr. Wong: 0 RTW Investments: 0 Dr. Wong: 0 N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.. RTW Investments, LP /s/ Roderick Wong, M.D. 05/15/2025 Roderick Wong, M.D. /s/ Roderick Wong, M.D. 05/15/2025