Prime Medicine (PRME) investor relations material

Platform and strategic approach

• Prime Editing is positioned as a versatile approach for permanent genetic correction, including substitutions, insertions, deletions, repeat excision and gene-sized insertions, without double-strand breaks or bystander edits.

• The platform flywheel reuses optimized editor components, delivery, regulatory frameworks, manufacturing processes and assays across programs.

• The patent estate includes 10 U.S. and 21 ex-U.S. issued patents covering Prime Editing, delivery technologies and therapeutics.

• Strategic priorities include focused liver and lung programs, partnerships beyond near-term internal areas, and access to enabling technologies.

Pipeline and milestones

• Wilson disease PM577a clinical trial is underway; initial data are anticipated in 2027, with follow-on programs planned for other common mutations.

• AATD PM647 IND is cleared; a Phase 1/2 trial is planned, with initial data anticipated in 2027.

• PM359 CGD development is progressing toward a planned BLA submission in H1 2027, following final FDA alignment.

• CF efforts include hotspot editing and PASSIGE gene insertion; in vivo delivery studies are ongoing, with CF Foundation funding supporting development.

• 2026–2027+ priorities include CF in vivo proof-of-concept, CF IND-enabling studies, PM647 trial initiation, and additional strategic partnerships.

Liver programs

• Wilson disease affects over 20,000 patients in the U.S. and Europe; 30–50% carry H1069Q, while R778L is predominant in Japan, with 7,500–15,000+ patients cited there.

• In humanized mouse models, editors corrected H1069Q and R778L; no detectable off-target editing was identified in patient-derived cells for PM577a.

• PM577a achieved ~45% editing associated with near-wild-type copper levels; treated mice also showed normal copper metabolism after radiolabeled copper challenge.

• PM577a is a single-IV-infusion, open-label Phase 1/2 trial in adults and adolescents with at least one H1069Q allele; primary endpoints are safety and tolerability.

• PM647 corrected the AATD mutation in vivo and restored M-AAT protein at clinically relevant doses; its trial targets adults with PIZZ AATD and includes lung-only and liver-involved groups.