GSK Presents Mepolizumab Phase III Results In ERS

GlaxoSmithKline announced that it presented positive results from two pivotal Phase III trials of asthma treatment mepolizumab at the European Respiratory Society (ERS) congress in Munich.

Mepolizumab is an investigational humanized IgG1 monoclonal antibody that specifically targets and inhibits interleukin-5. The drug blocks IL-5 from binding to its receptor found on the surface of eosinophils and, through its mechanism of action, reduces the levels of blood, tissue, and sputum eosinophils. First investigated in 2012 as an adjunct therapy for severe uncontrolled refractory asthma, mepolizumab is under assessment in the Phase III trials MENSA and SIRIUS as treatment for patients with severe eosinophilic asthma.

GSK reports that both trials met their primary endpoints. In the MENSA trial, patients in the mepolizumab treatment arm reached a statistically significant reduction in the frequency of serious asthma attacks compared to placebo. In the SIRIUS trial, patients achieved a statistically significant reduction of daily oral corticosteroid (OCS) dose at weeks 20 to 24 compared to the dose identified during the trial’s optimization phase. GSK also reported that patients who were treated with mepolizumab experienced improved quality of life and enhanced asthma control. The results were published in the New England Journal of Medicine (NEJM).

Steve Yancey, Medicine Development Leader for mepolizumab at GSK, said, “The relationship between over-expression of IL-5 and severe asthma has long been established, but it is only now that we have medicines that can target IL-5 as a possible way to manage eosinophilic inflammation. The combined results of these studies, taken with earlier results, confirm our belief that patients with severe eosinophilic asthma could benefit from mepolizumab.”

Yancey added that the company is pleased to share its findings regarding the potential of blood eosinophil levels as biomarkers to guide COPD treatment decisions. Asthma is often characterized by an accumulation of eosinophils or white blood cells in lung tissues. High levels of eosinophils are generally correlated with the severity and frequency of exacerbated asthma attacks, and these levels could be used to inform therapy decisions.

Reuters reports that the mepolizumab is ahead of similar asthma drugs from British drug maker, AstraZeneca, and Israeli generics firm, Teva. However, price is an important factor in the biotech lung drug race. While GSK has not given any hint as to the price of mepolizumab, analysts estimate that it might cost anywhere from $10,000 to $15,000 per patient for a year of treatment. The company said it has integrated cost-effectiveness studies in its marketing plan to showcase the drug’s value.

GSK is working toward submitting regulatory applications for mepolizumab for severe eosinophilic asthma by the end of the year.