Efficacy and Safety Study of Reslizumab to Treat Eosinophilic Esophagitis in Subjects Aged 5 to 18 Years

Inclusion Criteria: * written informed consent obtained * male or female patients aged 5 to 18 years at time of screening * of non-childbearing potential, of childbearing potential and willing to use specific barrier methods outlined in the protocol * confirmed active EE (at Screening or within six weeks prior to Baseline Visit) as defined by esophageal mucosal eosinophils greater than or equal to 24 per high power field (hpf; 400X magnification) * within the week prior to dosing, patient has one of the following symptoms of moderate (or worse) severity: vomiting, regurgitation (acid taste or feeling material movement upward), abdominal, chest pain/heartburn (burning or pain behind the sternum), or difficulty swallowing * been on a therapeutic dose of proton pump inhibitors (PPIs; with or without histamine H2 receptor antagonists)for at least four weeks without resolution of symptoms, or by negative pH probe (with or without having failed a course of PPIs) Exclusion Criteria: * another disorder that causes esophageal eosinophilia (e.g., hypereosinophilic syndrome \[HES\],Churg Strauss vasculitis, eosinophilic gastroenteritis \[EG\], or a parasitic infection) * history of abnormal gastric or duodenal biopsy or documented gastrointestinal \[GI\] disorders (e.g., celiac disease, Crohn's disease or Helicobacter pylori infection) * history of the following GI surgeries: fundoplication, gastric surgery or surgery for intestinal atresia * use of systemic immunosuppressive or immunomodulating agents (anti-immunoglobulin E \[IgE\] monoclinal antibody \[mAb\], methotrexate, cyclosporin, interferon alpha \[α\], or anti tumor necrosis factor \[TNF\] mAb) within six months prior to study entry * received attenuated live attenuated vaccines (e.g., measles, mumps, rubella \[MMR\], bacillus Calmette-Guerin \[BCG\], varicella, FluMist or polio) within three months prior to study entry * use of swallowed inhaled corticosteroids for the treatment of EE within one month prior to study entry. Note: Inhaled and nasal corticosteroids for the treatment of asthma and allergies, respectively, are permitted provided that the dose remains the same during the study * a stricture on endoscopy that prevents passage of the endoscope * participation in any investigational drug or device study within 30 days prior to study entry * female subjects who are pregnant or nursing * concurrent infection or disease that may preclude assessment of EE * concurrent immunodeficiency (human immunodeficiency \[HIV\], or acquired immunodeficiency syndrome \[AIDS\] or congenital immunodeficiency)