Baxter’s investigational drug BAX 817 is effective in the treatment of bleeding episodes in haemophilia A and B patients who stop responding to their current therapy, according to a phase III trial.
The study showed that BAX 817, a recombinant form of Factor VIIa, was able to resolve more than 90% of acute bleeds in male haemophiliacs who had developed inhibitors, an antibody response which occurs when the immune system recognises clotting factor therapies as foreign and try to block their effects.
On average one in three people with severe haemophilia A will develop inhibitors at some time in their life, with haemophilia B patients significantly less likely to suffer an episode. While most inhibitors are temporary, the data suggest BAX 817 can be used to treat breakthrough and sometimes life-threatening bleeds.
In the trial, 89% of BAX 817-treated patients achieved sustained bleeding control for all acute bleeding episodes 24 hours after infusion. Moreover, the drug did not appear to stimulate the development of inhibitors itself, according to Baxter.
“The development of inhibitors remains one of the most significant challenges in treating haemophilia, as it may place patients at increased risk for life-threatening complications resulting from difficult-to-treat bleeding episodes,” commented John Orloff, vice president and global head of R&D at Baxter BioScience.
The company said the trial would be presented at a medical conference later this year and would help form the basis of regulatory filings for BAX 817.
The drug is one of a series of new therapies Baxter is developing to extend its $4bn-plus haemophilia franchise, currently led by recombinant Factor VIII product Advate but facing competition from the likes of Biogen Idec’s long-acting rival Eloctate, which was launched in the US for haemophilia A last year, and Bayer’s BAY94-9027 which is in late-stage development.
Baxter has a long-acting version of Advate called BAX 855 that is due to be filed for approval in 2016 and in 2013 got approval for Factor IX product Rixubis (formerly BAX 326) for haemophilia B. It added to its portfolio last October after getting a US green light for Obizur for acquired haemophilia A, a rare and life-threatening form of the bleeding disorder.
When Baxter separates its biopharma and medical technology businesses in a few months time, its biopharma division, which includes its haemophilia interests, will operate under the name Baxalta.