Pfizer Receives Positive CHMP Opinion for its Treatment for Adults and Adolescents with Hemophilia A and B

• If approved in Europe, marstacimab is expected to become the first once-weekly subcutaneous treatment for people living with severe hemophilia B and the first to be administered via a pre-filled pen for people living with severe hemophilia A or B

NEW YORK, September 20, 2024 – Pfizer Inc. (NYSE: PFE) announced today that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion for marstacimab for the routine prophylaxis of bleeding episodes in adults and adolescents 12 years and older with severe hemophilia A (congenital factor VIII [FVIII] deficiency, FVIII <1%) without FVIII inhibitors, or severe hemophilia B (congenital factor IX [FIX] deficiency, FIX <1%) without FIX inhibitors.

Marstacimab is a once-weekly treatment that, if approved, will be administered subcutaneously as a flat (not weight-based) dose with a pre-filled, auto-injector pen. If approved by the European Commission, marstacimab is expected to become the first anti-tissue factor pathway inhibitor (anti-TFPI) to receive regulatory approval for the treatment of hemophilia A and B in eligible patients. The anti-TFPI mechanism is intentionally designed with the goal of restoring balance between bleeding tendency and blood clot formation.

“Current standard-of-care treatment options for hemophilia can cause unnecessary burdens for patients, including time-consuming preparation and administration of infusions and injections, often leading to missed doses and a heightened risk of bleeding,” said James Rusnak, M.D., Ph.D., Senior Vice President, Chief Development Officer, Internal Medicine and Infectious Diseases, Research and Development, Pfizer. “The positive recommendation of marstacimab is an important step forward for a potential treatment option that has demonstrated the ability to offer not only bleed protection and a generally manageable safety profile but also once-weekly subcutaneous administration in a pre-filled pen.”

The Marketing Authorization Application for marstacimab is based on results from the pivotal Phase 3 BASIS trial (NCT03938792) to evaluate the efficacy and safety of marstacimab in adults and adolescents 12 years and older with severe hemophilia A or B without inhibitors. The inhibitor cohort of the BASIS trial is ongoing, with results expected in the third quarter of 2025.

The European Commission, which grants central marketing authorizations in the European Union (EU), will review the CHMP recommendation and is expected to make a final decision in the coming months. If granted, the marketing authorization of marstacimab would be valid in all 27 EU member states, as well as in Iceland, Liechtenstein, and Norway. Marstacimab is also currently under review with the U.S. Food and Drug Administration (FDA), with a Prescription Drug User Fee Act (PDUFA) action date set for the fourth quarter of this year.

This milestone builds on Pfizer’s more than 40-year commitment to delivering breakthrough solutions to improve the lives of people living with hemophilia. Pfizer recently reported positive results from a Phase 3 program investigating a gene therapy in hemophilia A (giroctocogene fitelparvovec) and received regulatory approvals in Europe and the U.S. for its hemophilia B gene therapy.

About marstacimab
Discovered by Pfizer scientists, marstacimab is a rebalancing agent that targets the Kunitz 2 domain of tissue factor pathway inhibitor (TFPI), a natural anticoagulation protein that functions to prevent the formation of blood clots and restore hemostasis. Marstacimab is in development as a prophylactic treatment to prevent or reduce the frequency of bleeding episodes in individuals with severe hemophilia A or moderately severe to severe hemophilia B with or without inhibitors.

About the BASIS study
BASIS is a global Phase 3, open-label, multicenter study to evaluate the efficacy and safety of marstacimab in adolescent and adult participants ages 12 to <75 years with severe hemophilia A (defined as FVIII <1%) or moderately severe to severe hemophilia B (defined as FIX activity ≤2%) with or without inhibitors.

The European Marketing Authorization Application is based on data from 116 people living with severe hemophilia without inhibitors who were treated with marstacimab during a 12-month active treatment period (ATP) versus a routine prophylaxis (RP) or on-demand (OD) intravenous regimen with FVIII or FIX, administered as part of usual care in a six-month observational period. During the ATP, participants received prophylaxis (a 300 mg subcutaneous loading dose of marstacimab, followed by 150 mg subcutaneously once weekly) with potential for dose escalation to 300 mg once weekly.

About Hemophilia
Hemophilia is a family of rare genetic blood diseases caused by a clotting factor deficiency (FVIII in hemophilia A, FIX in hemophilia B), which prevents normal blood clotting. Hemophilia is diagnosed in early childhood and impacts more than 800,000 people worldwide.¹ The inability of the blood to clot properly can increase the risk of painful bleeding inside the joints, which can cause joint scarring and damage. People living with hemophilia can suffer permanent joint damage following repeated bleeding episodes.^2,3

For decades, the most common treatment approach for hemophilia A and B has been factor replacement therapy, which replaces the missing clotting factors. Factor replacement therapies increase the amount of clotting factor in the body to levels that improve clotting, resulting in less bleeding.^4,5

The burden of intravenous infusions is believed to be a barrier to treatment adherence for some people living with hemophilia due to inconvenience, in part due to time constraints as well as poor venous access.^6,7,8,9 In a patient/physician/specialist nurse survey across six European countries, lack of time for treatment and convenience were among the leading reasons for not using the prescribed amount of clotting factor or skipping treatment administration.⁶

About Pfizer: Breakthroughs That Change Patients’ Lives
At Pfizer, we apply science and our global resources to bring therapies to people that extend and significantly improve their lives. We strive to set the standard for quality, safety and value in the discovery, development and manufacture of health care products, including innovative medicines and vaccines. Every day, Pfizer colleagues work across developed and emerging markets to advance wellness, prevention, treatments and cures that challenge the most feared diseases of our time. Consistent with our responsibility as one of the world's premier innovative biopharmaceutical companies, we collaborate with health care providers, governments and local communities to support and expand access to reliable, affordable health care around the world. For 175 years, we have worked to make a difference for all who rely on us. We routinely post information that may be important to investors on our website at www.Pfizer.com. In addition, to learn more, please visit us on www.Pfizer.com and follow us on X at @Pfizer and @Pfizer_News, LinkedIn, YouTube and like us on Facebook at www.facebook.com/Pfizer/.

Disclosure notice
The information contained in this release is as of September 20, 2024. Pfizer assumes no obligation to update forward-looking statements contained in this release as the result of new information or future events or developments.

This release contains forward-looking information about marstacimab, an investigational anti-tissue factor pathway inhibitor and Pfizer’s other approved and investigational hemophilia products, including their potential benefits, that involves substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Risks and uncertainties include, among other things, the uncertainties inherent in research and development, including the ability to meet anticipated clinical endpoints, commencement and/or completion dates for our clinical trials, regulatory submission dates, regulatory approval dates and/or launch dates, as well as the possibility of unfavorable new clinical data and further analyses of existing clinical data; whether or when the inhibitor cohort of the BASIS trial will be successful; the risk that clinical trial data are subject to differing interpretations and assessments by regulatory authorities; whether regulatory authorities will be satisfied with the design of and results from our clinical studies; whether and when applications may be filed with regulatory authorities in particular jurisdictions for marstacimab or any other products or product candidates; whether and when any such applications that may be pending or filed for marstacimab (including the applications pending in Europe and the U.S. for marstacimab) or any other products or product candidates may be approved by regulatory authorities, which will depend on myriad factors, including making a determination as to whether the product’s benefits outweigh its known risks and determination of the product’s efficacy and, if approved, whether marstacimab or any such other products or product candidates will be commercially successful; decisions by regulatory authorities impacting labeling, manufacturing processes, safety and/or other matters that could affect the availability or commercial potential of marstacimab or any such other products or product candidates; uncertainties regarding the impact of COVID-19 on our business, operations and financial results; and competitive developments.

A further description of risks and uncertainties can be found in Pfizer’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 and in its subsequent reports on Form 10-Q, including in the sections thereof captioned “Risk Factors” and “Forward-Looking Information and Factors That May Affect Future Results”, as well as in its subsequent reports on Form 8-K, all of which are filed with the U.S. Securities and Exchange Commission and available at www.sec.gov and www.pfizer.com.

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¹ World Federation of Hemophilia. World Federation of Hemophilia Global Report on the Annual Global Survey 2022. https://www1.wfh.org/publications/files/pdf-2399.pdf.
² Srivastava A, Santagostino E, Dougall A, et al. WFH guidelines for the management of hemophilia, 3rd Edition; 2020. Haemophilia. 26(S6), 1–158. https://doi.org/10.1111/hae.14046.
³ Franchini M, Mannucci PM. Past, present and future of hemophilia: a narrative review. Orphanet J Rare Dis. 7, 24 (2012). https://doi.org/10.1186/1750-1172-7-24.
⁴ Centers for Disease Control and Prevention. Hemophilia. Last Reviewed: April 2023. https://www.cdc.gov/ncbddd/hemophilia/.
⁵ Weyand AC, Pipe SW. New therapies for hemophilia. Blood. 2019;133(5):389–398. https://doi.org/10.1182/blood-2018-08-872291.
⁶ De Moerloose P, Urbancik W, Van Den Berg HM, Richards M. A survey of adherence to haemophilia therapy in six European countries: results and recommendations. Haemophilia. 2008;14(5):931-8.
⁷ Hacker MR, Geraghty S, Manco-Johnson M. Barriers to compliance with prophylaxis therapy in haemophilia. Haemophilia. 2001;7(4):392-6.
⁸ Zappa S, McDaniel M, Marandola J, Allen G. Treatment trends for haemophilia A and haemophilia B in the United States: results from the 2010 practice patterns survey. Haemophilia. 2012;18(3):e140-53.
⁹ Geraghty S, Dunkley T, Harrington C, Lindvall K, Maahs J, Sek J. Practice patterns in haemophilia A therapy -- global progress towards optimal care. Haemophilia. 2006;12(1):75-81.

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