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Pfizer releases positive results from Phase III trial of BeneFIX to treat hemophilia B

PBR Staff Writer Published 18 July 2014

US-based Pfizer has released positive results from its Phase III trial comparing a prophylaxis regimen of BeneFIX Coagulation Factor IX (Recombinant) 100 IU/kg once-weekly to on-demand treatment in people with moderately severe to severe hemophilia B.

The two-period Phase III trial consisted of six months of on-demand therapy only, followed by 12 months of routine prophylaxis with BeneFIX 100 IU/kg once-weekly.

The open-label, non-randomized trial enrolled about 25 male patients with a mean age of 31.3 years and moderately severe to severe hemophilia B.

Results showed that the primary endpoint of the trial was met and hemophilia B patients taking once-weekly BeneFIX (100 IU/Kg) showed a statistically significant reduction in the annualised bleeding rate (ABR) relative to on-demand treatment with BeneFIX.

ABR value is a commonly used measure of efficacy for prophylaxis regimens in haemophilia.

In the trial, the median ABR value was 2.0 for the prophylaxis regimen, compared to 33.6 for the on-demand regimen, representing a 94% decrease in bleeding rates.

The company said that the mean ABR value was 3.6 for the prophylaxis period, compared to 32.9 for the on-demand treatment, which represents a reduction of 89%.

The results also showed that prophylaxis treatment reduced both spontaneous and traumatic ABR compared to on-demand treatment with BeneFIX.

Secondary endpoints of the trial showed that none of the 1,254 prophylaxis infusions administered were associated with a less than expected therapeutic effect (LETE) occurrence, which was defined as a spontaneous bleed occurring within 48 hours of a prophylaxis infusion.

The company said that adverse events observed in the trial, for both the prophylaxis and on-demand periods, were consistent with the known adverse event profile of BeneFIX.