GSK’s mepolizumab succeeds in Ph III severe eosinophilic asthma trial

UK pharma giant GlaxoSmithKline (LSE: GSK) says that a pivotal Phase III study of mepolizumab, an investigational IL-5 antagonist monoclonal antibody, met its primary endpoint of reduction in the frequency of exacerbations, in patients with severe eosinophilic asthma.

Mepolizumab could add £400 million ($668 million) to GSK's revenue by 2021, according to estimates from Barclays reported by The Wall Street Journal. Analysts from Deutsche Bank forecast £300 million in mepolizumab sales by 2018 for the company, already a leader in the asthma treatment sector.

The study (MEA115588) evaluated the efficacy of two-dose regimens of mepolizumab in the treatment of patients with severe eosinophilic asthma. Patients remained on their current asthma maintenance therapy throughout the study and were randomized to receive either mepolizumab 75mg intravenous (IV), 100mg subcutaneous (SC), or placebo every four weeks.