title: Anti-eosinophil activity and clinical efficacy of the CRTH2 antagonist OC000459 in eosinophilic esophagitis.
abstract: BACKGROUND
  Eosinophilic esophagitis (EoE) is a chronic, Th2-type inflammatory disease. Chemoattractant receptor-homologous molecule on Th2 cells (CRTH2) is a prostaglandin D(2) (PGD(2)) receptor, expressed by Th2 cells and other inflammatory cells, including eosinophils and basophils, that mediates chemotaxis and activation. OC000459 is a selective CRTH2 antagonist and would be expected to suppress eosinophilic tissue inflammation. The purpose of this study was to evaluate the efficacy and safety of an OC000459 monotherapy in adult patients with active, corticosteroid-dependent or corticosteroid-refractory EoE.
  
  
  METHODS
  In this randomized, double-blind, placebo-controlled trial, 26 adult patients (m/f = 22/4; mean age 41 years, range 22-69 years) with active EoE, dependent or resistant to corticosteroids, were treated either with 100 mg OC000459 (n = 14) or placebo (n = 12) twice daily. Pre- and post-treatment disease activity was assessed clinically, endoscopically, histologically, and via biomarkers. The primary end point was the reduction in esophageal eosinophil infiltration.
  
  
  RESULTS
  After an 8-week OC000459 treatment, the esophageal eosinophil load decreased significantly, from 114.83 to 73.26 eosinophils per high-power field [(eos/hpf), P = 0.0256], whereas no reduction was observed with placebo (102.80-99.47 eos/hpf, P = 0.870). With OC000459, the physician's global assessment of disease activity improved from 7.13 to 5.18 (P = 0.035). OC000459 likewise reduced extracellular deposits of eosinophil peroxidase and tenascin C, the effects not seen with placebo. No serious adverse events were observed.
  
  
  CONCLUSIONS
  An 8-week treatment with the CRTH2-antagonist, OC000459, exerts modest, but significant, anti-eosinophil and beneficial clinical effects in adult patients with active, corticosteroid-dependent or corticosteroid-refractory EoE and is well tolerated.
authors: Swiss EoE Clinic and EoE Research Network, Olten, Switzerland. alex.straumann@hin.ch
authors: A
authors: A
authors: Straumann
authors: S
authors: S
authors: Hoesli
authors: Ch
authors: Ch
authors: Bussmann
authors: M
authors: M
authors: Stuck
authors: M
authors: M
authors: Perkins
authors: L P
authors: LP
authors: Collins
authors: M
authors: M
authors: Payton
authors: R
authors: R
authors: Pettipher
authors: M
authors: M
authors: Hunter
authors: J
authors: J
authors: Steiner
authors: H-U
authors: HU
authors: Simon
mesh_terms: D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D057765:Eosinophilic Esophagitis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004804:Eosinophils / Q000187:drug effects*; D005260:Female; D006801:Humans; D007210:Indoleacetic Acids / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D011804:Quinolines / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use*; D011971:Receptors, Immunologic / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011982:Receptors, Prostaglandin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C571151:(5-fluoro-2-methyl-3-quinolin-2-ylmethylindo-1-yl)acetic acid; D000893:Anti-Inflammatory Agents; D007210:Indoleacetic Acids; D054328:Proton Pump Inhibitors; D011804:Quinolines; D011971:Receptors, Immunologic; D011982:Receptors, Prostaglandin; C036293:prostaglandin D2 receptor