The European Commission has approved Astellas’ overactive bladder treatment Betmiga (mirabegron).
It’s the first time in over 30 years that a new class of overactive bladder (OAB) treatment will reach the market and Betmiga is an important new drug for the company, which aims to take a dominant leadership position in the area.
Astellas’ Vesicare is the current OAB market leader and the company has said it expects combined sales of the two drugs to exceed ¥155bn (about $1.7bn) by 2014.
To date, the only available class oral OAB treatments has been anti-muscarinic agents, like Vesicare and Pfizer’s Detrol (tolterodine) franchise, but it is thought around half of patients currently stop taking this types of drug after only three months, often due to lack of efficacy or the drug’s side effects.
Compared with anti-muscarinics, Betmiga was found to have a low incidence of treatment-associated side effects, including dry mouth which is a particular problem with the earlier class of OAB drugs.
Astellas says of its new drug that “it is important that doctors will now be able to offer patients an alternative treatment that works in a different way”.
However, the company will have to be careful with how it positions Betmiga to avoid undermining Vesicare’s position.
Betmiga, which was approved in Japan in 2011 and in the US last June, works by improving the storage capacity of the bladder without inhibiting bladder voiding, thereby prolonging the time between trips to the toilet for the patient.
Its European approval came on the back of three phase III trials showing Betmiga demonstrated superior efficacy compared to placebo in the treatment of symptoms of OAB, with patients needing to visit a toilet significantly less frequently and experiencing fewer incontinence episodes.
The studies also showed statistically significant quality of life improvements over placebo in terms of treatment satisfaction and ‘symptom bother’, Astellas said.
OAB affects more than 400 million people worldwide and in Europe, while 30-40 per cent of people aged 75 or more are thought to be affected.