Stroke-Associated Letal Outcome with Hympavzi: Michael Makris on Pfizer’s Announcement
Michael Makris, Emeritus Professor of Haemostasis and Thrombosis at the University of Sheffield, Editor-in-Chief of RPTH Journal, shared on LinkedIn:
”Important.
Pfizer has just announced that a person with hemophilia, in their marstacimab (Hympavzi) clinical trial program, has died from a thrombotic stroke.
I attach the letter they sent to a number of patient organisations including the World Federation of Hemophilia.
The information provided in the letter is minimal.
I hope they reach out to all hemophilia doctors worldwide who can potentially prescribe this drug to inform them about this event, and the other thrombotic event in the same clinical trial that was previously disclosed at the EAHAD and ISTH meetings.
The patient who died, had hemophilia A with an inhibitor.
Marstacimab is at present only approved for persons with hemophilia A and B without an inhibitor.”

Stay updated with Hemostasis Today.
-
Oct 10, 2026, 17:58Archo Farzana Batool: Exploring Medical Writing Through an Article on Iron Deficiency Anemia
-
Oct 10, 2026, 17:53Assessing Frailty in Adults With Hemophilia – JTH
-
Oct 10, 2026, 17:52Fatma Sadeghi: Reducing Maternal Health Inequalities Through Nursing Advocacy
-
Oct 10, 2026, 17:50Grzegorz Hensler: How Apheresis Transformed Blood Cell Separation and Collection
-
Oct 10, 2026, 17:47Hemant K Sharma: Japan’s Universal Artificial Blood Research – A Potential Breakthrough in Transfusion Medicine
-
Oct 10, 2026, 17:40John Strouse: Learning About Bleeding Disorders and Sickle Cell Disease at FWGBD
-
Oct 10, 2026, 17:34Mae Caime: Speaking at the Annual Women’s Retreat for the Hemophilia Community in Florida
-
Oct 10, 2026, 17:30Chokri Ben Lamine: PNH beyond the Textbook Triad
-
Oct 10, 2026, 17:29Ruah Alyamany: Thrombosis and Anticoagulation in Hematological Malignancies at SOHO KSA 2026