of this Current Report on Form 8-K (this “Form 8-K”), including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any of the Company’s filings under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such f…

Results of Operations and Financial Condition. On May 12, 2026, PepGen Inc. (the “Company”) announced its financial results for the quarter ended March 31, 2026 and other business updates and issued a press release titled “ PepGen Reports First Quarter 2026 Financial Results and Recent Corporate Highlights .” A copy of the press release is furnished as Exhibit 99.1. The information provided in this Current Report on Form 8-K (this “Form 8-K”), including Exhibit 99.1, shall not be deemed “file…

Results of Operations and Financial Condition. On March 4, 2026, PepGen Inc. (the "Company") announced its financial results for the year ended December 31, 2025 and issued a press release titled "PepGen Reports Fourth Quarter and Year-End 2025 Financial Results and Recent Corporate Highlights". A copy of the press release is furnished as Exhibit 99.1. The information provided in this Current Report on Form 8-K (this “Form 8-K”), including Exhibit 99.1, shall not be deemed “filed” for purpose…

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on November 12, 2025 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN INC. Date: November 12, 2025 By: /s/ Noel Donnelly Noel Donnelly,…

The filing describes a repricing of underwater stock options for current employees, including executive officers.

Entry into a Material Definitive Agreement. On September 24, 2025, PepGen Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Leerink Partners LLC and Stifel, Nicolaus & Company, Incorporated, as joint book-running managers (the “Underwriters”), pursuant to which the Company agreed to issue and sell an aggregate of 31,250,000 shares (the “Firm Shares”) of its common stock, par value $0.0001 per share (the “Common Stock”), at a price to the public of…

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on August 7, 2025 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN INC. Date: August 7, 2025 By: /s/ Noel Donnelly Noel Donnelly, Chief…

Other Events. On May 28, 2025, the Company announced based on the levels of dystrophin protein measured in the 10 mg/kg cohort of its CONNECT1-EDO51 study investigating PGN-EDO51 in Duchenne muscular dystrophy (“DMD”) patients amenable to exon 51 skipping, the Company will focus on advancing its promising myotonic dystrophy type 1 (“DM1”) program currently in Phase 2 clinical development. The Company is voluntarily discontinuing development of PGN-EDO51 and intends to wind down all DMD-relate…

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on May 8, 2025 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN INC. Date: May 8, 2025 By: /s/ Noel Donnelly Noel Donnelly, Chief Financ…

Director — Mitchell Finer, Ph.D. and Lisa Wyman: The Board of Directors appointed Mitchell Finer, Ph.D. and Lisa Wyman to fill newly created vacancies on the Board resulting from an expansion.

Chief Medical Officer — Michelle L. Mellion, MD: Dr. Mellion resigned from her position as Chief Medical Officer.

Results of Operations and Financial Condition. On February 24, 2025, PepGen Inc. (the "Company") announced its financial results for the year ended December 31, 2024 and issued a press release titled "PepGen Reports Fourth Quarter and Year-End 2024 Financial Results and Recent Corporate Highlights". A copy of the press release is furnished as Exhibit 99.1. The information provided in this Current Report on Form 8-K (this “Form 8-K”), including Exhibit 99.1, shall not be deemed “filed” for pur…

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on November 7, 2024 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN, INC. Date: November 7, 2024 By: /s/ Noel Donnelly Noel Donnelly, C…

Director — Christopher Ashton, Ph.D.: Dr. Christopher Ashton resigned from the board of directors and his positions on the Audit Committee and Compensation Committee.

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on August 8, 2024 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN, INC. Date: August 8, 2024 By: /s/ Noel Donnelly Noel Donnelly, Chief…

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on May 14, 2024 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN, INC. Date: May 14, 2024 By: /s/ Noel Donnelly Noel Donnelly, Chief Fin…

of this Form 8-K shall be deemed to be furnished and not filed: Exhibit Number Description 99.1 Press release issued by PepGen Inc. on March 6, 2024 104 Cover Page Interactive Data File (embedded within Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PEPGEN INC. Date: March 6, 2024 By: /s/ Noel Donnelly Noel Donnelly, Chief Fi…

Entry into a Material Definitive Agreement. On February 6, 2024, PepGen Inc. (the “ Company ”) entered into an underwriting agreement (the “ Underwriting Agreement ”) with Leerink Partners LLC, as underwriter, pursuant to which the Company agreed to issue and sell an aggregate of 7,530,000 shares (the “ Shares ”) of its common stock, par value $0.0001 per share (the “ Common Stock ”), at a price to the public of $10.635 per share. The offering was made pursuant to the shelf registration state…