Mepolizumab: Additional Phase III data

Additional data from the double-blind, international Phase III MEA115588 (MENSA) trial in 576 patients showed that 100 mg subcutaneous mepolizumab given every 4 weeks for 32 weeks met the secondary endpoint of reducing the frequency of clinically significant asthma exacerbations requiring hospitalization vs. placebo. The 75 mg IV mepolizumab dose given every 4 weeks for 32 weeks missed the endpoint. Specifically, mepolizumab led to placebo-adjusted reductions of 39% at the low dose and 69% at the high dose (p=0.33 and p=0.03, respectively). On other secondary endpoints, IV and subcutaneous mepolizumab each significantly improved mean pre-bronchodilator FEV1 (placebo-adjusted improvements of 100 and 98 mL, respectively, p=0.025 and p=0.028) and SGRQ scores (placebo-adjusted improvements of 6.4 and 7 points, respectively, p<0.001 for both) from baseline to week 32 vs. placebo.

The trial enrolled patients with severe eosinophilic asthma with frequent exacerbations despite treatment with high-dose inhaled corticosteroids and >=1 other controller medication. Patients had a blood eosinophil count of >=150 cells/UL at initiation of treatment or blood eosinophils of >=300 cells/UL in the past 12 months. Data were published in The New England Journal of Medicine and presented at the European Respiratory Society meeting in Munich. GlaxoSmithKline previously reported that both formulations of mepolizumab met the primary endpoint of reducing the frequency of clinically significant asthma exacerbations vs. placebo (p<0.001 for both) (see BioCentury, March 17). ...