Mepolizumab: A Proven Alternative to Omalizumab

Frank Albers, MD, PhD

Two recent presentations reported improved control of asthma symptoms of patients who switched from omalizumab (Xolair) to mepolizumab (Nucala).

The new analyses of data from the OSMO study — an open-label, single arm study of patients with severe eosinophilic asthma that had not been optimally controlled with omlizumab — were presented at the joint meeting of the American Academy of Allergy, Asthma and Immunology and the World Allergy Organization (AAAAI/WAO) in Orlando, FL.

Frank Albers, MD, PhD, Global Medical Lead, GlaxoSmithKline, Chapel Hill, North Carolina described improvements in asthma control, quality of life and lung function outcomes at the primary endpoint of 32 weeks after switching biologics.

"Mepolizumab and omalizumab are indicated in distinct asthma prototypes, although some patients with severe eosinophilic asthma (SEA) are eligible for both biologics," Albers told attendees.

The OSMO multi-center study identified 145 patients with SEA who had experienced at least 2 exacerbations in the year prior to study screening despite regular high-dose inhaled glucocorticoids and other controller medication(s) including omalizumab for at least 4 months. The study group had not achieved targeted control of symptoms for an average of 2.5 years while treated with omalizumab.

At baseline, patients with poor asthma control, corresponding to Asthma Control Questionnaire-5 (ACQ-5) score of at least 1.5, discontinued omalizumab and began mepolizumab 100mg subcutaneously every 4 weeks for 28 weeks.

Albers reported that at week 32, the ACQ=5 score had improved by -1.45 points, with 77% experiencing the minimal clinically important difference of at least 0.5-point reduction. Similar improvement was found in the St George's Respiratory Questionnaire (SGRQ) total score. The pre- and post-bronchodilator forced expiratory volume in one second (FEV₁) improved at week 32 by 159 ml (Standard Error [SE] ±41) and 120 ml (±36), respectively.

"In uncontrolled patients with SEA, switching directly from omalizumab to mepolizumab resulted in clinically significant improvements in asthma control, health status, and lung function," Albers concluded.

In a separate presentation on analysis of exacerbations and safety outcomes, Dmitry Galkin, MD, PhD, Global Medical Director, GlaxoSmithKline, Raleigh-Durham, North reported that there was also a clinically significant reduction in exacerbations, as well as exacerbations requiring emergency department (ED) visits or hospitalizations. In comparison to 3.26 exacerbation events and 0.63 ED/hospitalizations in the 12 months prior to screening, there was 1.18 and 0.19 events per year, respectively, during the study period. Galkin reported that there were no safety issues arising during the study.

"Patients participating in this (OSMO) study suffered burdensome day to day asthma symptoms and frequently required access to urgent care when their asthma symptoms significant worsened," Ken Chapman, MD, Professor of Medicine, University of Toronto and a co-investigator in both reports, said in a statment. "This study is a valuable addition to our understanding of how to manage patients with biologic therapies."

The presentation on asthma control, quality of life and lung function outcomes from the OSMO study was L29 and the presentation on exacerbations and safety outcomes was L30 at the AAAAI/WAO joint meeting in Orlando, Florida, March 2-5.