Research Study

A Multi-centre, Open Label, Single Arm, 32-week Treatment Study in Subjects With Severe Eosinophilic Asthma Not Optimally Controlled With Current Omalizumab Treatment Who Are Switched From Omalizumab to Mepolizumab 100mg Subcutaneous (Study Number 204471- the OSMO Study)
Principal Investigator 
Mark FitzGerald


Body Locations and Systems 
Closed to Recruitment
Study Start/End 
Mar 23, 2016 to Jan 25, 2018
Diamond Health Care Centre
Shelley Ambercromby, Research Coordinator
604-875-4111 ext.62500
Purpose of Study 

Mepolizumab is an anti-interleukin-5 ( IL-5) monoclonal antibody that neutralizes IL-5 and reduces eosinophil counts in both sputum and blood. Omalizumab an anti-immunoglobulin E (IgE) monoclonal antibody (mAb) is effective in the treatment of moderate to severe allergic asthma. The aim of this study is to investigate whether subjects not optimally controlled on their current omalizumab treatment, who are eligible for therapy with mepolizumab can be effectively and safely switched to treatment with mepolizumab to improve asthma control. The study will provide data on the efficacy, safety, immunogenicity, and tolerability of mepolizumab when switched directly from omalizumab without any wash-out. The learnings from this study may help guide physicians when substituting one biologic with another for the treatment of patients with severe eosinophilic asthma.

The study will be a multi-centre, open-label single arm trial. Patients with severe eosinophilic asthma who are receiving omalizumab, but are not optimally controlled will be eligible to participate. Subjects will remain on their current maintenance therapy including omalizumab throughout the run-in period for a minimum of one week and up to 4 weeks. At Visit 2 (week 0) subjects will discontinue their omalizumab treatment and be switched to mepolizumab 100 mg subcutaneous (SC) every 4 weeks for 28 weeks. The treatment period is 32 weeks, including an Exit Visit/Early Withdrawal Visit, 4 weeks following the subject's last dose of mepolizumab.


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Study Coordinators and Research Nurses cannot give medical advice over the phone. Telephone numbers and email addresses are provided for obtaining additional information on specific clinical research trials only. If you have specific questions which require clinical expertise, please call your primary care physician.