Study Description:

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.

GSK Study ID:

204471 Identifier:


EudraCT Number:


Study Overview

Medical Conditions







March 2016 to May 2017








12 years - N/A

Accepts Healthy Volunteers


This study has Protocol summary on Click here to learn more.


  • Central Contact :

    US GSK Clinical Trials Call Center

  • Central Contact Phone:


  • Central Contact Email:

    [email protected]

Argentina, Ciudad Autónoma de Buenos Aires C1426ABPCompleted
Argentina, Buenos Aires, Florencio Varela 1888Completed
Argentina, Buenos Aires, Florida 1602Completed
Argentina, Buenos Aires, La Plata 1900Completed
Argentina, Buenos Aires, Quilmes B1878FNRCompleted
Argentina, Santa Fe, Rosario 2000Completed
Belgium, Erpent 5101Completed
Canada, Alberta, Calgary T2N 4Z6Completed
Canada, Alberta, Sherwood Park T8H 0N2Completed
Canada, British Columbia, Vancouver V5Z 1M9Completed
Canada, Ontario, Ajax L1S 2J5Completed
Canada, Ontario, Mississauga L5A 3V4Completed
Canada, Ontario, Toronto M5T 3A9Completed
Canada, Ontario, Toronto M4V 1R2Completed
Canada, Ontario, Windsor N8X 2G1Completed
Canada, Québec, Montreal H3T1E2Completed
France, Bordeaux cedex 33076Completed
France, Grenoble cedex 9 38043Completed
France, Lyon cedex 04 69317Completed
France, Marseille Cedex 20 13915Completed
France, Montpellier cedex 5 34295Completed
France, Nantes cedex 1 44093Completed
France, Paris Cedex 18 75877Completed
France, Toulouse Cedex 9 31059Completed
Germany, Berlin, Berlin 12203Completed
Germany, Berlin, Berlin 10717Completed
Germany, Hessen, Neu-Isenburg 63263Completed
Germany, Niedersachsen, Hannover 30173Completed
Germany, Sachsen, Leipzig 04357Completed
Netherlands, DORDRECHT 3318 ATCompleted
Netherlands, ROTTERDAM 3045 PMCompleted
Spain, Barcelona 08035Completed
Spain, Hospitalet de Llobregat 08907Completed
Spain, Murcia 30003Completed
Spain, Pozuelo de Alarcón/Madrid 28223Completed
Spain, Santiago de Compostela. La Coruña. 15706Completed
Spain, Valencia 46017Completed
Spain, Cantabria, Laredo 39770Completed
Sweden, GÖTEBORG SE-413 45Completed
Sweden, STOCKHOLM SE-141 86Completed
United States, Alabama, Birmingham 35209Completed
United States, California, Riverside 92506Completed
United States, California, Roseville 95661Completed
United States, California, San Diego 92123Completed
United States, California, Upland 91786Completed
United States, Maryland, Baltimore 21224Completed
United States, New Jersey, Piscataway 08854Completed
United States, New York, Rochester 14642Completed
United States, North Carolina, Charlotte 28277Completed
United States, North Carolina, Durham 27705Completed
United States, Rhode Island, East Providence 02914Completed
United States, Virginia, Richmond 23229Completed
United States, Virginia, Williamsburg 23188Completed

Study Design

  • Primary Purpose: Treatment
  • Allocation: Not Available
  • Study Design: Single Group Assignment
  • Study Classification: Not Available
  • Masking: Not Available
  • Masked Subject: No
  • Masked Caregiver: No
  • Masked Investigator: No
  • Masked Assessor: No
Primary Outcomes:

  • Mean Change from Baseline in Asthma Control Questionnaire-5 (ACQ-5) score at Week 32
    Timeframe: Baseline and at Week 32

Secondary Outcomes:

  • Mean change from Baseline in St. George’s Respiratory Questionnaire (SGRQ) score at Week 32
    Timeframe: Baseline and at Week 32

  • The rate of clinically significant asthma exacerbations over 32 weeks’ treatment
    Timeframe: Up to Week 32

  • Ratio to Baseline in blood eosinophil count at Week 32
    Timeframe: Baseline and at Week 32

  • 1


  • Drug: Mepolizumab 100mg SC
  • Drug: Albuterol/salbutamol MDIs
  • Drug: Omalizumab


  • mepolizumab, Omalizumab, SGRQ, severe eosinophilic asthma, ACQ, exacerbations
Inclusion / Exclusion Criteria: Click to view inclusion/exclusion criteria:
Enrollment: 145