A recombinant factor VIII (rFVIII) product known as BAX 855 can prevent bleeding in hemophilia A patients, according to Baxter International, the company developing the product.
BAX 855 is a pegylated version of ADVATE, a full-length rFVIII product already approved to treat hemophilia A.
In a phase 3 study, BAX 855 met the primary endpoint of reducing annualized bleed rates (ABRs) among hemophilia A patients when used as prophylaxis rather than on-demand treatment.
The trial included 138 patients age 12 and older with previously treated hemophilia A. The patients received BAX 855 either twice weekly (45 IU/kg) or on-demand and were followed for 6 months.
The primary objective was to show that BAX 855 prophylaxis can reduce ABRs compared to on-demand treatment. The researchers’ other objectives were to evaluate the safety and immunogenicity of the compound when administered as prophylaxis or on-demand.
BAX 855 met its primary endpoint in the control and prevention of bleeding, routine prophylaxis, and perioperative management.
Patients in the twice-weekly prophylaxis arm experienced a 95% reduction in median ABR compared to those 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 1 or 2 infusions.
The half-life of BAX 855 was 1.4 to 1.5 times that of ADVATE, which is consistent with the findings from a phase 1 study.
No patients developed inhibitors to BAX 855 and no treatment-related serious adverse events, including hypersensitivity, were reported. The most common treatment-related adverse event was headache, which occurred in 3 patients.
Baxter said it expects to submit a biologics license application for BAX 855 to the US Food and Drug Administration before the end of 2014 and to present additional trial data in the coming months.
In addition to an ongoing continuation study for patients who have completed the pivotal trial, the company is starting a phase 3 study to evaluate the safety and efficacy of BAX 855 among 60 previously treated hemophilia A patients younger than 12 years of age.
Consistent with guidelines published by the European Medicines Agency that require a study in children less than 12 years of age prior to filing, Baxter expects to file a marketing authorization application with the agency upon the completing the pediatric study.