Marstacimab a monoclonal antibody with trade name Hympavzi
Routes ofnadministration Intravenous
Drug class Tissue factor pathway inhibitor
A monoclonal antibody medication used for the treatment of hemophilia A and hemophilia B.
is a tissue factor pathway inhibitor (TFPI) antagonist.
Rather than replacing a clotting factor, it works by reducing the amount, and therefore, the activity of, the naturally occurring anticoagulation protein called tissue factor pathway inhibitor.
This increases the amount of thrombin, an enzyme that is critical in blood clotting, that is generated.
This is expected to reduce or prevent the frequency of bleeding episodes.
The most common side effects include injection site reactions, headache, and itching/
Marstacimab is indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in people aged twelve years of age and older with hemophilia A (congenital factor VIII deficiency) without factor VIII inhibitors, or hemophilia B (congenital factor IX deficiency) without factor IX inhibitors.
The US prescription label for marstacimab contains warnings and precautions about circulating blood clots thromboembolic events, hypersensitivity, and embryofetal toxicity.
The most common side effects include injection site reactions, headache, and itching.
BASIS study:
In an open-label, multi-center study in adult and pediatric male participants with either severe hemophilia A or severe hemophilia B, both without inhibitors:
For the first six months of this study, participants received treatment with replacement factor either on-demand or prophylactically.
These participants then received marstacimab prophylaxis for twelve months.
In the participants receiving on-demand factor replacement during the first six months of the study, the estimated annualized bleeding rate was 38 compared to the estimated annualized bleeding rate during treatment with marstacimab of 3.2, showing that marstacimab was superior to on-demand factor replacement.
In the initial six-month period during which participants received prophylactic factor replacement, the estimated annualized bleeding rate was 7.85 and was 5.08 during the subsequent twelve months on marstacimab prophylaxis, showing that marstacimab provided similar bleeding rates.