Patients with haemophilia A could cut the number of infusions they receive in half if a long-acting factor VIII product from Bayer reaches the market.
A phase III trial of BAY94-9027 found that the drug was able to provide protection against bleeding episodes even when a week passed between infusions. Using current factor VIII products haemophilia A patients typically need to be dosed every two or three days.
BAY94-9027 is a recombinant Factor VIII that has been ‘PEGylated’, with a polyethylene glycol (PEG) side chain added to the molecule to extend its half-life in the body. In the 36-week study – called PROTECT VIII – the drug provided protection from bleeds when used every seven days, every five days and twice a week.
Moreover, Bayer’s drug was also effective for on-demand treatment of breakthrough bleeds, resolving 91 per cent of them with one or two infusions, and there was no evidence that patients developed inhibitors that could limit the effectiveness of treatment.
This effect has hit Bayer’s previous drug hopes, with the company halting development of the haemophilia A and B BAY 86-6150 candidate – which had reached phase II/III testing – after it was found to stimulate a neutralising antibody response in patients.
Jerry Powell, director of the Haemophilia Treatment Center at the University of California Davis, described the results for the latest candidate as “very encouraging.”
“We have found that this investigational site-specific PEGylated factor VIII could protect users from bleeds associated with haemophilia A, even when used every seven days,” he said.
Bayer already has a strong position in the haemophilia A market with its Kogenate recombinant factor VIII product, which achieved sales of around €1.2bn last year and is second in the market behind Baxter’s Advate, and sees BAY94-9027 as a means of extending its franchise.
The company is facing stiff competition in the long-acting factor VIII category however, with Biogen Idec filing for approval of its Eloctate candidate last year. The filing has been hit by a short delay at the FDA, but the drug could be approved for marketing in the US by the middle of 2014.
Meanwhile, Baxter, Novo Nordisk and CSL Behring also have long-acting haemophilia A candidates in clinical trials.