title: Oral glucocorticoid-sparing effect of mepolizumab in eosinophilic asthma.
abstract: BACKGROUND
  Many patients with severe asthma require regular treatment with oral glucocorticoids despite the use of high-dose inhaled therapy. However, the regular use of systemic glucocorticoids can result in serious and often irreversible adverse effects. Mepolizumab, a humanized monoclonal antibody that binds to and inactivates interleukin-5, has been shown to reduce asthma exacerbations in patients with severe eosinophilic asthma.
  
  
  METHODS
  In a randomized, double-blind trial involving 135 patients with severe eosinophilic asthma, we compared the glucocorticoid-sparing effect of mepolizumab (at a dose of 100 mg) with that of placebo administered subcutaneously every 4 weeks for 20 weeks. The primary outcome was the degree of reduction in the glucocorticoid dose (90 to 100% reduction, 75 to less than 90% reduction, 50 to less than 75% reduction, more than 0 to less than 50% reduction, or no decrease in oral glucocorticoid dose, a lack of asthma control during weeks 20 to 24, or withdrawal from treatment). Other outcomes included the rate of asthma exacerbations, asthma control, and safety.
  
  
  RESULTS
  The likelihood of a reduction in the glucocorticoid-dose stratum was 2.39 times greater in the mepolizumab group than in the placebo group (95% confidence interval, 1.25 to 4.56; P=0.008). The median percentage reduction from baseline in the glucocorticoid dose was 50% in the mepolizumab group, as compared with no reduction in the placebo group (P=0.007). Despite receiving a reduced glucocorticoid dose, patients in the mepolizumab group, as compared with those in the placebo group, had a relative reduction of 32% in the annualized rate of exacerbations (1.44 vs. 2.12, P=0.04) and a reduction of 0.52 points with respect to asthma symptoms (P=0.004), as measured on the Asthma Control Questionnaire 5 (in which the minimal clinically important difference is 0.5 points). The safety profile of mepolizumab was similar to that of placebo.
  
  
  CONCLUSIONS
  In patients requiring daily oral glucocorticoid therapy to maintain asthma control, mepolizumab had a significant glucocorticoid-sparing effect, reduced exacerbations, and improved control of asthma symptoms. (Funded by GlaxoSmithKline; SIRIUS ClinicalTrials.gov number, NCT01691508.).
authors.affiliation: From the Department of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam (E.H.B.); the Department of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh Asthma Institute at the University of Pittsburgh Medical Center-University of Pittsburgh School of Medicine, Pittsburgh (S.E.W.); the Lung Institute of Western Australia, Nedlands, and the Centre for Asthma, Allergy and Respiratory Research, University of Western Australia, Crawley - both in Australia (P.J.T.); Respiratory Therapeutic Area, GlaxoSmithKline, Research Triangle Park, NC (C.M.P., S.W.Y., H.G.O.); and Clinical Statistics, GlaxoSmithKline, Stockley Park (O.N.K.), and the Respiratory Medicine Unit, Nuffield Department of Medicine, University of Oxford, Oxford (I.D.P.) - both in the United Kingdom.
authors.forename: Elisabeth H
authors.initials: EH
authors.lastname: Bel
authors.forename: Sally E
authors.initials: SE
authors.lastname: Wenzel
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Thompson
authors.forename: Charlene M
authors.initials: CM
authors.lastname: Prazma
authors.forename: Oliver N
authors.initials: ON
authors.lastname: Keene
authors.forename: Steven W
authors.initials: SW
authors.lastname: Yancey
authors.forename: Hector G
authors.initials: HG
authors.lastname: Ortega
authors.forename: Ian D
authors.initials: ID
authors.lastname: Pavord
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage* / Q000009:adverse effects; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004802:Eosinophilia; D005260:Female; D005541:Forced Expiratory Volume; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D057194:Intention to Treat Analysis; D060046:Maintenance Chemotherapy; D008297:Male; D008875:Middle Aged
chemical_list: D018927:Anti-Asthmatic Agents; D061067:Antibodies, Monoclonal, Humanized; D005938:Glucocorticoids; C434107:mepolizumab