Positive Phase III Results Reported for BAX 855 in Treatment of Hemophilia A
Prophylaxis more effective than on-demand therapy
Positive results have been reported from a phase III pivotal trial of BAX 855 (Baxter), an investigational, extended half-life recombinant factor VIII (rFVIII) treatment for hemophilia A based on Advate (antihemophilic factor [recombinant], Baxter).
Top-line results from the prospective, global, multicenter study demonstrated that BAX 855 met its primary endpoint in the control and prevention of bleeding, routine prophylaxis, and perioperative management for patients 12 years of age or older.
BAX 855 was evaluated in 138 adolescent and adult patients with previously treated hemophilia A. The patients received BAX 855 (45 IU/kg) twice weekly or on demand, and were followed for 6 months. The study’s primary endpoint was the reduction in annualized bleeding rate (ABR) during the treatment period compared with on-demand treatment. The study also evaluated the safety and immunogenicity of the compound when administered as either prophylaxis or on-demand treatment regimens.
Patients in the twice-weekly prophylaxis arm experienced a 95% reduction in the median ABR compared with patients in the on-demand arm (1.9 vs. 41.5, respectively). BAX 855 was also effective in treating bleeding episodes, 96% of which were controlled with one or two infusions.
The half-life of BAX 855 was 1.4 to 1.5 times that of Advate, which was consistent with findings from a phase I study. No patients developed inhibitors to BAX 855, and no treatment-related serious adverse events, including hypersensitivity, were reported. The most common product-related adverse event was headache.
It is anticipated that a biologics license application (BLA) for BAX 855 will be submitted to the FDA before the end of 2014.
In addition to an ongoing continuation study for patients who completed the pivotal phase III trial, a phase III, prospective, open-label, multicenter study will be initiated to evaluate the safety and efficacy of BAX 855 in 60 previously treated patients under the age of 12 with severe hemophilia A.
BAX 855 is based on Advate, which uses proprietary PEGylation technology to extend the duration of activity of full-length FVIII molecules in the body. This PEGylation technology has been in use for more than 10 years in a number of approved medications that treat chronic or serious conditions.
Source: Baxter; August 21, 2014.