FDA approves Baxter drug for rare form of haemophilia

Baxter has won US approval for its new drug to treat bleeding in a rare form of haemophilia.

The US FDA last week approved Obizur in adults with acquired haemophilia A, a rare and life-threatening form of the bleeding disorder. It is caused by the development of antibodies in the body that attack FVIII, a protein crucial to blood clotting.

Acquired haemophilia A differs from inherited haemophilia A, which is passed on genetically. Instead, people can develop the acquired form of the disorder as part of another health condition, such cancer of pregnancy or due to certain medications, although in half of cases no underlying cause can be found.

Obizur, which was classified as an orphan drug due to the rarity of the condition, works by replacing the affected FVIII protein in the body with a version of FVIII derived from a pig. According to Baxter, this version of factor VIII is less susceptible to attack from human antibodies.

The FDA's decision was based on a phase II/III trial that investigated Obizur's ability to treat serious bleeding episodes in 29 adults with acquired haemophilia A.

All patients treated with the drug demonstrated at least a reduction in bleeding at 24 hours after the first infusion, while 86% had successful treatment of the initial bleeding episode.

Baxter said the drug will be commercially available in the US in the coming months and is currently under regulatory review in Europe and Canada.

The company has as strong heritage in haemophilia, with the division accounting for $3.44bn of Baxter's total $6.56bn biopharma sales for 2013. This was led by haemophilia A therapy Advate, a long-acting version of which is due to be filed by the end of the year.

When Baxter separate its biopharma and medical technology businesses in mid-2015, its biopharma division, which includes its haemophilia interests, will operate under the name Baxalta, while the new Baxter will focus on drug delivery systems and dialysis and hospital products.

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