David Green, MD, PhD

Weekly prophylaxis with nonacog beta pegol was safe and effective.

The goal of treatment for patients with hemophilia B (Christmas disease, factor IX deficiency) is to control bleeding and prevent joint destruction. This is accomplished by regular intravenous infusions of factor IX concentrate. Current research is focused on reducing the frequency of infusions by extending the half-life of recombinant factor IX.

To examine the safety and efficacy of a long-acting recombinant factor IX (nonacog beta pegol) prepared by site-directed glycoPEGylation, investigators conducted an industry-sponsored, multinational, randomized, single-blind, phase III clinical trial involving 67 patients with hemophilia B (factor IX, ≤2 IU/dL). Patients received weekly prophylactic doses of nonacog beta pegol (10 IU/kg or 40 IU/kg) or on-demand treatment (40 IU/kg) for bleeding episodes.

During 52 weeks of prophylaxis, mean trough factor IX levels were significantly above 1 IU/dL in the 10- and 40-IU/kg arms (8.5 and 27.3 IU/dL, respectively). In those receiving 40 versus 10 IU/kg or on-demand dosing, spontaneous bleeding episodes were less frequent (34 vs. 91 or 102), bleeding was more likely to cease after one injection (99% vs. 84% or 84%), and median annualized bleeding rates were 1.04, 2.93, and 15.58. In those receiving 40 IU/kg, 45% had no bleeding episodes, and 10 of 15 with target joints (≥3 bleeds into a joint in the 6 months prior to the trial) had no further bleeding into these joints. No patient developed inhibitors, and no serious adverse events were attributed to the study drug.

Citation(s):

Collins PW et al. Recombinant long-acting glycoPEGylated factor IX in hemophilia B: A multinational randomized phase 3 trial. Blood 2014 Sep 26; [e-pub ahead of print].