Pfizer’s anti-tissue factor pathway inhibitor Hympavzi (marstacimab-hncq) has been approved by the US Food and Drug Administration (FDA) to treat haemophilia A or B in adult and paediatric patients aged 12 years and older.
Hympavzi, which is now the first in its drug class to be approved in the US for haemophilia A or B, has been specifically authorised for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in patients with haemophilia A without factor VIII inhibitors or haemophilia B without factor IX inhibitors.
More than 800,000 people globally are affected by haemophilia, a family of rare genetic blood disorders caused by a clotting factor deficiency.
Despite recent progress in haemophilia treatment, many patients continue to experience repeated bleeding episodes and manage their condition with frequent intravenous infusions that may need to be given multiple times a week.
Administered as a once-weekly subcutaneous injection, Hympavzi works by reducing the amount of the naturally occurring anticoagulation protein, tissue factor pathway inhibitor. This increases the amount of thrombin, an enzyme critical in blood clotting, that is generated.
The FDA’s decision was supported by positive results from the late-stage BASIS trial, in which Hympavzi reduced the annualised bleeding rate for treated bleeds by 35% and 92% after a 12-month active treatment period compared to routine prophylaxis and on-demand treatment, respectively, in patients with haemophilia A or B without inhibitors.
Ann Farrell, director of the division of non-malignant haematology in the FDA’s Center for Drug Evaluation and Research, said the approval “provides patients with haemophilia a new treatment option that is the first of its kind to work by targeting a protein in the blood clotting process”.
The authorisation comes less than six months after the FDA approved Pfizer’s one-time haemophilia B gene therapy Beqvez (fidanacogene elaparvovec-dzkt) for use in certain adults with moderate-to-severe cases of the disorder. The company also has a range of recombinant factor treatments.
Aamir Malik, Pfizer’s chief US commercial officer and executive vice president, said: “We look forward to launching this latest medical breakthrough and to now offer three distinct classes of haemophilia medicines… that can meet the unique treatment needs of a wide range of patients.”