Omalizumab to Treat Eosinophilic Gastroenteritis
Condition: Gastroenteritis
MeSH terms: Gastroenteritis; Eosinophilic Esophagitis
Study type: Interventional
Phase: Phase 2

Summary: 
      This study will evaluate the safety and usefulness of omalizumab (anti-IgE, Xolair) in
      reducing eosinophil counts and improving symptoms in patients with eosinophilic
      gastroenteritis (EG). EG is a disorder of unknown cause in which eosinophils, a type of white
      blood cell, are increased in the blood and gut tissue. Patients with EG have symptoms like
      stomach pain, bloating, and vomiting. About 50 percent of EG patients have food or
      environmental allergies, which may play a role in EG. Some patients with EG improve
      significantly on diets avoiding foods to which they are allergic. Immunoglobulin E (IgE) is
      an antibody that plays an important role in initiating allergic reactions. Omalizumab is a
      monoclonal antibody directed against IgE. The Food and Drug Administration approved
      omalizumab in 2003 for treating patients 12 years of age and older with allergic asthma.

      Patients between 12 and 76 years of age with eosinophilic gastroenteritis who have a blood
      eosinophil count of 500 or more and who have a food allergy or allergy to an inhaled allergen
      may be eligible for this study. Candidates are screened with a medical history, physical
      examination, and blood and urine tests.

      Participants undergo the following procedures:

        -  Leukapheresis. This procedure is done to collect quantities of white blood cells to
           study the effects of omalizumab on eosinophils and other immune substances. Blood flows
           from a needle placed in an arm vein through a catheter (plastic tube) into a machine
           that separates the blood into its components by centrifugation (spinning). Some of the
           white cells are removed and the rest of the blood (red cells, plasma and platelets) is
           returned to the body through a needle in the other arm.

        -  Skin testing. Participants are tested for allergies to specific substances. A small
           amount of various allergens (substances that cause allergies) are placed on the
           subject's arm. The skin is pricked at the sites of the allergens and the skin reaction
           after several minutes is observed.

        -  Upper and lower endoscopy. One or both of these procedures is done, depending on the
           part of the gastrointestinal tract that is involved, to examine the tract. If both
           procedures are done, they are performed at the same time. For the upper endoscopy, the
           subject's throat is sprayed with a numbing medicine and a long, flexible tube is passed
           through the esophagus, stomach and small intestine. For the lower endoscopy, the tube is
           passed through the rectum into t...
    

Detailed description: 
      Eosinophilic gastroenteritis (EG) is characterized by eosinophilic infiltration of the bowel
      wall, gastrointestinal symptoms, and in more than 50% of patients, peripheral eosinophilia.
      Approximately one half of EG patients have multiple food allergies and/or elevated
      immunoglobulin E (IgE), suggesting an allergic etiology. The purpose of this study is to
      evaluate the safety and efficacy of humanized monoclonal anti-IgE antibody, omalizumab
      (Xolair (Registered Trademark)), in eosinophilic gastroenteritis. Omalizumab is approved for
      use in asthma and is dosed subcutaneously based on serum total IgE level and body weight,
      with a maximum dose of 375 mg every 2 weeks. Subjects with EG, and either food
      hypersensitivity or environmental allergies will be admitted to the Clinical Center. All
      subjects will undergo a thorough clinical evaluation, including endoscopy. The primary
      endpoints will be the evaluation of safety of omalizumab and its efficacy in reducing
      peripheral blood absolute eosinophil count. In addition, the following secondary endpoints
      will be studied: symptom scores, study drug pharmacodynamics, and tissue eosinophilia. Blood
      cells and serum will be collected and evaluated in the laboratory to address issues related
      to the immunopathogenesis and treatment of EG. This study will provide a better understanding
      of inflammatory and allergy mediators in the pathogenesis of EG and may provide a potential
      therapy for EG. Following subcutaneous administration of the initial dose of omalizumab
      (maximum 375 mg), subjects will be followed as inpatients for a minimum of 24 hours to
      monitor for adverse effects. Subsequent doses will be administered biweekly for a total of 8
      doses.
    

Intervention name(s): Omalizumab
Intervention type(s): Drug
Intervention MeSH terms: Omalizumab
Primary purpose: Treatment
Keywords: Allergy; IgE; Eosinophil; Monoclonal Antibody; Eosinophilic Gastroenteritis; EG