rIX-FP filed with the FDA for Hemophilia B-CSL Behring

CSL Behring has submitted a biologics license application (BLA) to the FDA for the marketing authorization of its rIX-FP (recombinant coagulation factor IX with recombinant albumin). Once approved by the FDA, rIX-FP will provide people with Hemophilia B and their physicians a long-acting treatment option with dosing intervals up to 14 days. The submission is based on the results from the PROLONG-9FP Phase II/III (patients ages 12 to 61 years) study.

The study was an open-label, multicenter, safety, pharmacokinetic (PK) and efficacy study of rIX-FP in previously treated patients with severe hemophilia B (FIX < 2%). It was designed to compare the change in frequency of spontaneous bleeding events between on-demand treatment and a weekly prophylaxis regimen in patients previously receiving only on-demand treatment; and the number of patients developing inhibitors against factor IX as primary outcome measures. All prophylaxis patients maintained weekly treatment for the entire study, with mean and median annualized spontaneous bleeding rates of 1.26 and 1.13, respectively. All bleeding was treated successfully with two or fewer infusions of rIX-FP, with 95.3 percent of events treated with a single infusion.