GlaxoSmithKline (GSK), one of the world’s leading research-based pharmaceutical and healthcare companies, announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has issued a positive opinion recommending marketing authorisation for mepolizumab, which will be commercialised under the brand name Nucala, as an add-on treatment for severe refractory eosinophilic asthma in adult patients.  

This decision is based on the results from the clinical study programme, which identified the patients that may be suitable for treatment with mepolizumab. Severe refractory eosinophilic asthma patients who participated in the phase III trials were evaluated by eosinophil level and either a history of recurrent exacerbations or dependency on systemic corticosteroids. All patients were on high-dose inhaled corticosteroids plus another maintenance treatment.

Dave Allen, head, respiratory therapy area unit, R&D, said, “For these difficult-to-treat patients there are very limited treatment options. Many struggle to control their asthma even when taking high doses of inhaled therapies and are often reliant on daily oral corticosteroids, which can cause serious long-term side effects. This positive opinion brings us a step closer to adding a targeted biologic therapy, specifically developed for patients with severe eosinophilic asthma, to our respiratory portfolio.”

Mepolizumab is an anti-IL 5 monoclonal antibody which stops IL-5 from binding to its receptor on the surface of eosinophils. Inhibiting IL-5 binding in this way reduces blood, tissue and sputum eosinophil levels. It is delivered in a 100mg dose via subcutaneous injection every four weeks. The phase III clinical development programme for mepolizumab investigated the efficacy and safety of mepolizumab in 915 patients with severe asthma who received mepolizumab in addition to standard of care. All patients in studies MEA115588 and MEA115575 had peripheral blood eosinophil levels greater than or equal to 150 cells/µL at initiation of treatment or greater than or equal to 300 cells/µL within the past 12 months.

The Marketing Authorisation Application for mepolizumab was submitted to the EMA in November 2014. The CHMP positive opinion is a formal recommendation to grant marketing authorisation for mepolizumab. If approved, mepolizumab would be the first anti-IL5 biological treatment approved for use in this difficult-to-treat population.  The final decision will be made by the European Commission and is anticipated before the end of 2015.

Mepolizumab is not currently approved for use anywhere in the world. Regulatory applications in a number of other countries, including the USA and Japan, have been submitted and are under review. Further submissions are planned during the course of 2015 and 2016.

In the pivotal studies of mepolizumab, the overall adverse event profile was similar between those patients receiving mepolizumab and patients receiving standard of care. The most commonly reported adverse reactions during treatment were headache (very common - may affect one or more in ten people), injection site reactions and back pain.

Other commonly reported adverse events, which may affect one or more in 100 people (but less than one in ten), were lower respiratory tract infections, urinary tract infections, sore throat (pharyngitis), nasal congestion, upper area of abdominal pain, eczema, fever (pyrexia), systemic non-allergic administration-related reactions (including rash, flushing and myalgia) and hypersensitivity reactions (e.g. urticaria, angioedema, rash, bronchospasm, hypotension).

Local injection site reactions were higher in patients receiving mepolizumab subcutaneously, but were normally transient and not considered as severe. No events of anaphylaxis were attributed to mepolizumab.

Current estimates indicate that as many as 242 million people live with asthma worldwide. For many of these patients, existing therapies can provide adequate control of their symptoms if used appropriately. Approximately 5-10 per cent of patients are estimated to have severe asthma. Studies suggest that approximately 60 per cent of patients with severe asthma have eosinophilic airway inflammation; this group represents up to 3 per cent of the total number of people with asthma.

Severe asthma is defined as “asthma that requires treatment with high dose inhaled corticosteroids (ICS) plus a second controller (and/or systemic corticosteroids) to prevent it from becoming ‘uncontrolled’ or which remains ‘uncontrolled’ despite this therapy” Severe asthma patients are also often categorised by long-term use of oral corticosteroids (OCS). In a sub-set of severe asthma patients, the over-production of eosinophils (a type of white blood cell) is known to cause inflammation in the lungs that can affect the airways, limiting breathing and increasing the frequency of exacerbations. Interleukin-5 (IL-5) is the main promoter of eosinophil growth, activation and survival and provides an essential signal for the movement of eosinophils from the bone marrow into the lung.