Nektar Therapeutics (NASDAQ: NKTR) reported today that partner Baxter International Inc. announced that the company has submitted a new drug application (NDA) to Japan's Ministry of Health, Labour and Welfare for the approval of BAX 855, an investigational, extended half-life recombinant factor VIII (rFVIII) treatment based on ADVATE [Antihemophilic Factor (Recombinant)] for patients over 12 years of age with hemophilia A.
"We continue to advance BAX 855 as a potential new treatment for hemophilia A patients around the world who are seeking options that support their individual needs," said John Orloff, M.D., vice president and global head of research and development for Baxter BioScience. "With more than a decade of experience with ADVATE and an extensive global presence, our BAX 855 program represents our continued commitment to supporting the hemophilia community, particularly this week as we celebrate World Hemophilia Day with our colleagues around the globe."
The submission follows the filing to the United States Food and Drug Administration (FDA) in late 2014 and is based on positive results from a prospective, global, Phase 3 study of 137 previously treated patients (PTP). The results, presented during the European Association for Haemophilia and Allied Disorders (EAHAD) meeting in February 2015, demonstrated that BAX 855 met its primary endpoint in the control and prevention of bleeding episodes and routine prophylaxis for patients who were 12 years or older.
Patients in a twice-weekly prophylaxis arm experienced a 95 percent reduction in median annual bleed rate (ABR) as compared to those in the on-demand arm (1.9 vs. 41.5, respectively). BAX 855 was also effective in treating bleeding episodes, 96 percent of which were controlled with one or two infusions. No patients developed inhibitors to BAX 855 and no treatment-related serious adverse events, including hypersensitivity, were reported. The most common product-related adverse reaction was headache (3 patients).
Baxter continues to advance a continuation study for patients who completed the pivotal trial and a Phase 3 study among previously treated patients under the age of 12 with severe hemophilia A. Once the pediatric study has been completed, the company expects to file for marketing authorization with the European Medicines Agency in 2016 and intends to seek post-approval label expansion in the U.S. for previously-untreated pediatric patients.
BAX 855 is based on ADVATE, a full-length FVIII molecule with more than 12 years of real-world experience. Through a collaboration with Nektar Therapeutics, BAX 855 leverages proprietary pegylation technology designed to extend the duration of activity of the protein in the body. This proprietary technology has been used for over 10 years in a number of approved medicines that treat chronic or serious conditions.