Once weekly BeneFIX Coagulation Factor IX for prophylaxis versus on demand haemophilia B results published in Haemophilia - Pfizer

Pfizer Inc. announced the publication of the Phase III study results of a once-weekly regimen of BeneFIX Coagulation Factor IX (recombinant) 100 IU/kg prophylaxis versus on-demand treatment in people with moderately severe or severe hemophilia B. The findings were published in Haemophilia, the official journal of the World Federation of Hemophilia.

The study showed that the median ABR (annualized bleeding rate) values were 2.0 (range, 0.0-13.8) for the prophylaxis period and 33.6 (range, 6.1-69.0) for the on-demand period. The mean ABR values were 3.6 ± 4.6 for the prophylaxis period and 32.9 ±17.4 for the on-demand period, which were statistically significantly different (p <0.0001). During the 52 weeks of the prophylaxis period, 36 percent of patients experienced no bleeding events of any kind, and 48 percent of patients experienced no spontaneous bleeding events.

Almost half (47 percent) of the 17 factor IX activity levels measured approximately one week post-dose were greater than 2 IU/dL (2.1-10.4IU/dL), and three patients had zero ABR despite a factor IX activity level of zero. In the study, the adverse events reported for the prophylactic regimen were similar to those reported for on-demand treatment. The most common adverse events, occurring in 10 percent or more of patients during either regimen, were arthralgia, back pain, headache, joint swelling, local swelling, nasopharyngitis, pharyngitis, pyrexia, toothache and upper respiratory tract infection. Neither inhibitors nor thrombotic events were reported.

Comment: In the US BeneFIX is indicated for the control and prevention of bleeding episodes in adult and pediatric patients with hemophilia B. It is not cleared for prophylactic use. In Europe BeneFIX is cleared for both treatment and prophylaxis.