Abstract
Summary
This summary describes a study that looked at how well the study treatment marstacimab works in people living with hemophilia. The summary describes how people treated bleeding events while taking marstacimab.
Hemophilia is a condition that causes people to bleed more easily because their blood is unable to clot properly. Clotting is when blood turns from liquid into gel to stop bleeding. Hemophilia is caused by not having enough blood clotting factors, which are proteins found in the blood that will help in forming a clot and stop bleeding. People living with hemophilia either don’t make these proteins, have low amounts of these proteins, or these proteins do not work well.
Some treatments for hemophilia work by replacing clotting factors. These treatments are called factor replacement therapy and are given directly into a vein (called intravenous, or IV for short). They are given frequently, sometimes even more than once a week. Some people living with hemophilia develop antibodies called inhibitors against the factor replacement therapy, which causes the treatment to be ineffective. If people make these antibodies, it is called hemophilia with inhibitors.
A different way to treat people living with hemophilia is using treatment called non-factor replacement therapy. One type of non-factor treatment targets a protein in the blood called tissue factor pathway inhibitor, or TFPI for short. A treatment called marstacimab attaches to TFPI and stops its activity. Marstacimab is given as a regular preventative (prophylaxis) treatment. For people living with hemophilia, marstacimab can help blood to form a clot when needed.
Marstacimab is taken less often than clotting factors and is given once a week as an injection under the skin (called subcutaneous), which can be easier than injecting directly into a vein. This injection is sometimes called a shot. Marstacimab offers a new way to treat people living with hemophilia without inhibitors.
In this study, people who received regular preventative treatment with marstacimab and experienced bleeds were able to manage their bleeds with factor replacement therapy. People could usually treat bleeds with a single infusion of factor replacement therapy. None of the people in the study developed harmful blood clots when they took regular preventative treatment with marstacimab and infusions of factor replacement therapy as needed to treat their bleeds.
The study showed that people taking marstacimab can still use factor replacement therapy to treat a bleed.
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Acknowledgements
This plain language summary was written by one of the authors of the original article. Pfizer thanks all the people who took part in the study, their caregivers and supporters, and all study staff. Medical writing assistance was provided by Marion James, PhD, Engage Scientific Solutions Ltd, and was funded by Pfizer Inc.
Ethics approval and consent to participate
Individuals were enrolled into the study following institutional review board or ethics committee approvals at each investigational site in accordance with Good Clinical Practice and the Declaration of Helsinki. All individuals provided written informed consent before enrolling in the research study.
Author contributions
Hae Kyung Kim: conceptualization, writing – review and editing
Funding
This BASIS study was sponsored by Pfizer Inc.
Conflict of interest statement
Hae Kyung Kim is an employee and stockholder of Pfizer.
Availability of data and material
Upon request, and subject to review, Pfizer will provide the data that support the findings of this study. Subject to certain criteria, conditions, and exceptions, Pfizer may also provide access to the related individual de-identified participant data.