A new treatment, BETMIGA(TM) (mirabegron) has received approval from the European Commission (EC) for the treatment of overactive bladder (OAB) symptoms in adults.[1] Mirabegron represents the first new class of oral treatment in OAB for over 30 years. Currently around half of patients discontinue OAB treatment after only three months, often due to lack of efficacy or side effects,[2],[3] so it is important that doctors will now be able to offer patients an alternative treatment that works in a different way.
OAB is defined as urinary urgency, with or without urgency incontinence, usually with increased daytime frequency and nocturia (waking up at night one or more times to empty the bladder).[4] OAB affects more than 400 million people worldwide.[5] In Europe,OAB affects approximately 17% of men and women and increases to 30-40% for those aged over 75 years.[6] In a survey carried out in OAB patients, 65% felt OAB had adversely affected their daily life.[6] Symptoms can affect family, social and work life, as well as mental and physical wellbeing,[7] and across OAB patients, depression scores are higher, whilst quality of life scores are lower.[8]
Mirabegron will offer doctors an alternative to antimuscarinic agents, the only other class of approved oral treatment previously available for OAB. Mirabegron has a completely different mechanism of action to antimuscarinics;[9] it improves the storage capacity of the bladder without inhibiting bladder voiding, decreasing the number of times patients need to visit the toilet.[10] Dry mouth is one of the most common and bothersome side effects of antimuscarinics and often the reason for discontinuation of treatment. In comparison, studies have shown that mirabegron has a low incidence of treatment-associated side effects, including dry mouth.[9],[11],[12],[13],[14]
Dr Ayad Abdulahad, Vice President Medical Affairs and Health Economics for Astellas Pharma Europe Ltd., commented: "This is an important landmark highlighting Astellas' continued service to patients with overactive bladder, and we are delighted to be able to make a new treatment available to them. We know that many patients discontinue their current treatments as a result of bothersome side effects or because they simply don't feel they are getting a worthwhile benefit. We really hope that Betmiga(TM) can help change that and allow patients, whose lives are significantly disrupted by OAB on a daily basis, the opportunity to think about something other than their symptoms."
"The introduction of mirabegron should lead to a shift in how we treat OAB symptoms in adults. It has been over 30 years since a new class of oral treatment was available for OAB patients so we are looking forward to being able to offer an effective medication without the more bothersome side effects associated with antimuscarinics," commented Professor Chris Chapple, Consultant Urological Surgeon at Sheffield Teaching Hospitals and Lead Investigator of the mirabegron 12 month safety and tolerability study. "I see patients every day who are struggling to cope with this chronic condition. OAB can have a significant impact on a patient's quality of life. The introduction of mirabegron offers existing patients and those newly diagnosed with OAB a real alternative to current treatments."
The European Commission granted approval of mirabegron following the recommendation by the Committee for the Medicinal Products for Human Use (CHMP) in October 2012. They reviewed extensive clinical trial evidence from 7 Phase II / III studies in which over 5,000 patients received mirabegron, including 3 Phase III double-blind, randomised controlled trials conducted in the US and Europe-Australia.[11],[12],[13] In the trials, mirabegron 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.[11],[12],[13] In the trials, mirabegron was also well tolerated and exhibited a good safety profile.[11],[12],[13] In terms of quality of life, research presented at the 2011 American Urological Association (AUA) annual congress demonstrated that patients with OAB who received mirabegron reported significant improvements in treatment satisfaction, symptom bother, disease perception and quality of life, in comparison with patients taking a placebo.[15]
