Prime Medicine — November 2026 Earnings Summary

Financial Performance:

• Cash, cash equivalents, investments, and restricted cash totaled $108.8 million as of June 30, 2026.
• Cash runway extends into 2027.
• The company has received an $110 million upfront payment from Bristol Myers Squibb, including a $55 million equity investment.
• Potential milestone payments from the Bristol Myers Squibb collaboration exceed $3.5 billion, comprising $185 million in preclinical milestones, $1.2 billion in development milestones, and over $2.1 billion in commercial milestones, plus royalties on net sales.
• The Cystic Fibrosis Foundation provided up to $15 million in January 2024 and $24 million in July 2025 to support Cystic Fibrosis development.

Guidance and Future Outlook:

• Initial clinical data for PM577a (Wilson Disease) and PM647 (AATD) are anticipated in 2027.
• A Biologics License Application (BLA) for PM359 in Chronic Granulomatous Disease (CGD) is planned for submission in the first half of 2027 following final FDA alignment.
• The company aims to capitalize on platform modularity to advance follow-on Prime Editors for additional Wilson Disease mutations (e.g., R778L in Asia) and other liver programs.
• Prime Medicine expects Prime Editing to address approximately 90% of genetic diseases and opportunities in non-genetic diseases.
• Future plans include expanding the liver franchise and identifying opportunities for organic growth or business development.

Business Segments and Product Lines:

• Wilson Disease (PM577a): Clinical trial initiated for the H1069Q mutation; the program targets over 20,000 patients in the US and EU and 7,500–15,000+ in Japan. Preclinical data showed ~45% editing efficiency restored copper levels to near wild-type levels.
• Alpha-1 Antitrypsin Deficiency (PM647): IND cleared for a Phase 1/2 trial targeting PiZZ genotype patients; preclinical data demonstrated efficient correction resulting in M-AAT protein restoration.
• Chronic Granulomatous Disease (PM359): Ex vivo CAR-T program showing rapid neutrophil and platelet engraftment (2-3 weeks) and sustained NADPH oxidase activity recovery (~3-4x therapeutic threshold by day 30) in two patients with no serious adverse events attributed to the treatment.
• Cystic Fibrosis: Development funded by the Cystic Fibrosis Foundation; in vitro data shows phenotypic restoration of G542X mutated CFTR; efforts to develop LNP in vivo delivery to humanized mice and large animals are ongoing.
• Immunology and Oncology: Strategic collaboration with Bristol Myers Squibb to develop ex vivo CAR-T products using PASSIGE technology, enabling non-viral, multiplex-edited cell therapies.
• Platform: The proprietary modular LNP delivery system is designed for liver targeting, with the majority of components remaining consistent across liver programs to accelerate development and reduce costs.

Market and Competitive Landscape:

• Prime Medicine holds 10 U.S. and 21 ex-U.S. issued patents covering any permutation of Prime Editing, delivery technologies, and therapeutics.
• The technology distinguishes itself by permanently correcting genetic alterations without causing double-strand breaks or bystander edits, unlike CRISPR-Cas9 nuclease editors which showed detectable off-target edits, large deletions, or translocations in comparative analyses.
• The company positions Prime Editing as the most versatile gene editing technology with potential for platform-based regulatory approvals.
• In the liver market, the company targets large genetic diseases with no approved curative therapies, leveraging a modular approach to address multiple mutations within the same disease.

Risks and Challenges:

• Forward-looking statements regarding clinical trial timing, data release, regulatory approvals, and commercialization are subject to risks and uncertainties, including the ability to obtain regulatory approval and launch products.
• Actual results may differ materially from plans due to risks described in the company's Form 10-K, including estimates of expenses, capital requirements, and the need for additional financing.
• The company faces risks related to the continued development and optimization of delivery systems and the scope of intellectual property protection.
• Third-party data and internal estimates used in the presentation have not been independently verified for accuracy or completeness.

Management Commentary and Tone:

• Management emphasizes "disciplined clinical development" and the goal to "maximize platform impact" while ensuring access to breakthrough therapies.
• The tone is confident regarding the "curative potential" of Prime Editing, citing breakthrough clinical data in CGD and efficient preclinical correction in liver diseases.
• Leadership highlights the strategic value of partnerships with the Cystic Fibrosis Foundation and Bristol Myers Squibb to accelerate pipeline development and bolster financial resources.
• The company aims to leverage the modularity of the Prime Editing platform to rapidly advance programs for a majority of Wilson Disease patients and expand into other therapeutic areas.

Other Key Points:

• Bristol Myers Squibb Collaboration: A broad, multi-target strategic license and collaboration agreement was entered in September 2024 to develop and commercialize multiple ex vivo T cell products in immunology and oncology.
• Cystic Fibrosis Foundation Agreements: Agreements were signed in January 2024 and July 2025 for up to $15 million and $24 million, respectively, to support Prime Editor development for Cystic Fibrosis.
• PASSIGE Technology: A non-viral, multiplex-edited gene editing approach capable of inserting multi-kilobase sequences without double-strand breaks, utilized in the BMS collaboration and for potential in vivo applications.
• Intellectual Property: The patent estate covers any combination or permutation of a CRISPR-Cas enzyme, template Guide RNA, and Reverse Transcriptase.
• Clinical Safety: No detectable off-target editing, large deletions, or translocations have been observed in lead programs, including the CGD program, compared to Cas9 nuclease controls.