Roche's haemophilia drug a breakthrough, says FDA

Roche's bid to enter the $11 billion haemophilia market has been boosted by the award of breakthrough status for one of its drug candidates by the US FDA.

The designation has been given to ACE910, a double-headed (bispecific) antibody which simultaneously binds to both Factor IXa and Factor X and mimics the effect of Factor VII, the usual treatment for haemophilia A.

Analysts have suggested it could disrupt a market currently dominated by Factor VIII products from Baxalta, Bayer and Novo Nordisk as well as new entrant Biogen, with UBS recently issuing a research note suggesting that it has the potential to render current drugs obsolete.

The promise for the new drug lies in the fact that it is thought to work regardless of whether the patient has developed neutralizing antibodies to Factor VIII products, which can occur in as many as 30 per cent of those with severe haemophilia A.

The development of inhibitors is a serious complication of haemophilia A treatment, according to Roche, as it makes it very difficult to achieve a level of Factor VIII sufficient to control bleeding with traditional replacement therapies.

Earlier studies have suggested that ACE910 was able to completely prevent bleeding episodes in half of patients (nine of 18) with haemophilia A treated with a subcutaneous injection of the drug given once a week.

Preliminary data suggest that the drug could also have potential for once-monthly dosing, which trumps the once-weekly dosing of even the newest haemophilia A therapies, such as Biogen's Eloctate (efmoroctocog alfa).

Some patients on the drug have developed antibodies to it, but these were non-neutralising and did not appear to affect the activity of the drug.

Roche is preparing to initiate a phase III trial of ACE910 in patients with haemophilia A and factor VIII inhibitors by the end of the year, followed by a phase III trial in patients without inhibitors in 2016. Additionally, a trial in paediatric patients with haemophilia A is scheduled for 2016. The drug has come out of Roche's long-standing partnership with Japan's Chugai.

Haemophilia A is a rare, inherited blood clotting disorder that can lead to prolonged bleeding, bruising and joint and tissue damage. It is caused by having substantially reduced, or no, factor VIII activity, which is needed for normal blood clotting.

A World Federation of Haemophilia global survey published in 2012 estimates that approximately 142,000 people worldwide are identified as living with haemophilia A.

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