v3.26.1
Document And Entity Information
Jun. 18, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Jun. 18, 2026
Entity Registrant Name PepGen Inc.
Entity Central Index Key 0001835597
Entity Emerging Growth Company true
Entity File Number 001-41374
Entity Incorporation, State or Country Code DE
Entity Tax Identification Number 85-3819886
Entity Address, Address Line One 321 Harrison Avenue
Entity Address, Address Line Two 8th Floor
Entity Address, City or Town Boston
Entity Address, State or Province MA
Entity Address, Postal Zip Code 02118
City Area Code (781)
Local Phone Number 797-0979
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Ex Transition Period false
Title of 12(b) Security Common stock, par value $0.0001 per share
Trading Symbol PEPG
Security Exchange Name NASDAQ