EU Approves Pfizer's Hemophilia Therapy Hympavzi

The European Commission has granted approval to Pfizer's Hympavzi (marstacimab) for treating adults and adolescents with severe hemophilia A or B who do not have inhibitors. This announcement was made on Wednesday. Hympavzi, an anti-tissue factor pathway inhibitor (anti-TFPI), is administered as a once-weekly subcutaneous injection. It received similar approval in the United States in September.

According to Pfizer, Hympavzi is the first anti-TFPI therapy approved in Europe. Moreover, it is the first hemophilia treatment in the region to be administered using a pre-filled, auto-injector pen. Alexandre de Germay, Pfizer's chief international commercial officer, expressed enthusiasm about providing this medication, which not only reduces bleeding episodes compared to factor prophylaxis but also requires minimal preparation, addressing a significant need for eligible patients.

Hympavzi is specifically indicated for routine prophylaxis of bleeding episodes in patients aged 12 years and older, weighing at least 35 kg, with severe hemophilia A without FVIII inhibitors or severe hemophilia B without FIX inhibitors. The approval was based on data from the Phase III BASIS study. This study demonstrated that Hympavzi significantly reduced the annualized bleeding rate (ABR) for treated bleeds by 35% during a 12-month active treatment period. The results showed that Hympavzi was non-inferior and superior to routine prophylaxis (RP) with FVIII or FIX, which are typically administered as part of standard care.

Despite Hympavzi's approval, competition looms, particularly in Europe, where Novo Nordisk's anti-TFPI monoclonal antibody Alhemo (concizumab) is expected to be a contender. Nonetheless, key opinion leaders (KOLs) interviewed by FirstWord believe that Hympavzi's once-weekly dosing offers a considerable advantage over Alhemo's daily administration.

In addition to Hympavzi, Pfizer has also seen other recent successes in the field of hemophilia treatment. Earlier this year, the company received European approval for its gene therapy Durveqtix (fidanacogene neparvovec) to treat adults with moderate-to-severe hemophilia B. Similarly, Pfizer's gene therapy for hemophilia A, giroctocogene fitelparvovec, which is being developed in partnership with Sangamo Therapeutics, yielded positive results from the Phase III AFFINE trial in July.