Study: Pfizer Hemophilia Drug Reduces Bleeding Rates

    Photo: Wikimedia Commons

    The Facts

    • On Tuesday, US drugmaker Pfizer announced the results of a late-stage study for its experimental hemophilia therapy, marstacimab, claiming that the drug reduced bleeding rates in patients with severe hemophilia A and moderately severe to severe hemophilia B without inhibitors.

    • The phase 3 BASIS clinical trial of the under-the-skin therapy, which blocks the anticoagulant protein known as tissue factor pathway inhibitor (TPFI), reportedly demonstrated superiority compared to prophylaxis and on-demand factor replacement therapies, reducing bleeding by 35% and 92%, respectively.


    The Spin

    Narrative A

    This study's results are promising and could be the first step towards Pfizer's marstacimab revolutionizing treatment for patients with hemophilia A or B. These results suggests the drug could prevent excessive bleeds and reduce treatment burden through once-weekly, under-the-skin administration.

    Narrative B

    While the experimental therapy is undeniably innovative — as it reduces the amount of anticoagulation instead of addressing the factor deficiency — TFPI blockers in marstacimab can cause clotting episodes that do not usually show up in small studies. The medical community should not get too excited about this development too soon.


    Articles on this story

    Sign up to our daily newsletter