New Coagulation Factor Shows Promise as Once-Weekly Prophylaxis for Hemophilia B
Bleeding reduced compared with on-demand treatment
Positive results have been reported from a phase III trial comparing a prophylactic regimen of BeneFIX coagulation factor IX, recombinant (Pfizer) 100 IU/kg once-weekly with on-demand treatment in subjects with moderately severe to severe hemophilia B (also known as congenital factor IX deficiency and Christmas disease).
The study’s primary endpoint was met, and patients with hemophilia B treated with once-weekly BeneFIX showed a statistically significant reduction in the annualized bleeding rate (ABR) compared with on-demand treatment with BeneFIX (P < 0.0001).
In the study, the median ABR value was 2.0 for the prophylaxis regimen compared with 33.6 for the on-demand regimen, representing a 94% decrease in bleeding rates. The mean ABR value was 3.6 for the prophylaxis period compared with 32.9 for the on-demand treatment, which represented a reduction of 89% (P < 0.0001).
The study results also showed that prophylaxis treatment significantly reduced both spontaneous and traumatic ABR compared with on-demand treatment with BeneFIX. The median spontaneous ABR value was 1.0 for the prophylaxis regimen compared with 22.4 for the on-demand regimen, and the median traumatic ABR value was 1.0 for the prophylaxis period compared with 4.1 for the on-demand treatment.
In addition to meeting the primary endpoint, the secondary study endpoints showed that none of the 1,254 prophylaxis infusions administered during the study was associated with the occurrence of a less-than-expected therapeutic effect, which was defined as a spontaneous bleed occurring within 48 hours of a prophylaxis infusion. Most (82.1%) of the bleeding episodes in the prophylaxis arm were resolved after one infusion.
The most common adverse events reported during the prophylaxis treatment period included arthralgia (20%), upper respiratory infection (20%), toothache (20%), pyrexia (16%), headache (16%), pharyngitis (12%), back pain (12%) and local swelling (12%). No inhibitor development, thrombotic events, or allergic reactions were observed.
BeneFIX is a recombinant coagulation factor IX product indicated for the control, prevention, and perioperative management of bleeding episodes in adult and pediatric patients with hemophilia B. The product is not approved for prophylactic use in the U.S.
Source: Pfizer; July 16, 2014.