Baxter’s recombinant Factor IX product Rixubis has been approved by the FDA for haemophilia B, becoming the first new drug in the class in more than 15 years.
Rixubis (formerly BAX 326) has been cleared for routine prophylaxis and control of bleeding episodes in adult haemophilia B patients, as well as for managing bleeding during surgical procedures.
It is the only recombinant Factor IX product on the US market with labelling covering both prophylaxis and control, according to Baxter, which notes that most haemophilia B patients in the US are treated with an on-demand regimen.
The company said it intends to file for approval of Rixubis in the EU later this year.
At the moment, the leading recombinant Factor IX product on the US market is Pfizer’s BeneFix, which posted sales of $775m last year and is approved for control and prevention of bleeding episodes and perioperative management.
Baxter said recently it expects the market for a recombinant Factor IX product with a prophylactic indication in haemophilia B could be worth as much as $1.1bn a year.
The approval is based on a phase I/III study which showed that twice-weekly prophylactic treatment with Rixubis for six months achieved a median annualised bleed rate (ABR) of 2.0 with 43 per cent of patients experiencing no bleeds at all over the period.
Overall, patients in the prophylaxis study had a 75 per cent lower annual bleeding rate when compared to patients who have historically received on-demand treatment, said the FDA in a statement. An additional study in a paediatric haemophilia B population is also ongoing.
Shift towards long-acting?
Stiff competition could be looming for Rixubis however in the form of longer-acting Factor IX products, including Biogen Idec’s Fc fusion protein product which was submitted for approval in the US earlier this year and will require dosing once every week or two weeks. Current haemophilia B drugs typically require two to three injections per week for prophylaxis.
Meanwhile, following behind Biogen Idec’s candidate are two other long-acting Factor IX products from Novo Nordisk and CSL Behring, both of which are phase III testing.