Un estudio piloto del tratamiento de la esofagitis eosinofílica con omalizumab

INTRO:

Eosinophilic Esophagitis (EoE) is characterized by obstructive esophageal symptoms and dense esophageal eosinophilia in children and young adults. EoE appears to be a TH- 2, IL-5, mast cell, IgE associated disease process similar to the immune mechanisms involved in asthma. Omalizumab is a recently developed anti-IgE antibody that selectively binds to human IgE and has been shown to be effective in treatment of extrinsic asthma. We hypothesized that Omalizumab would be effective in the treatment of EoE. Aim: To determine the efficacy of omalizumab in reducing the eosinophilic esophageal infiltration in EoE patients. The secondary objective is to determine the efficacy of omalizumab in reducing the symptoms of EoE.

METHODS:

Prospective randomized, double-blind, placebo-controlled trial of subjects (age 12-60) who were either refractory to or relapsed after a trial of therapy with topical corticosteroids. EoE was defined as the presence of esophageal symptoms (dysphagia, chest pain, food impaction, heartburn) and ≥20 eos/ hpf averaged from 4 quadrant biopsies taken from proximal and distal esophagus. Subjects were placed on PPI therapy for duration of study to exclude GERD. Subjects were randomized to receive omalizumab or placebo at Day 1 and every 4 weeks for 16 weeks. Dysphagia scores were obtained at baseline and every 4 weeks. Wilcoxon signed rank and rank sum tests were used to compare dysphagia scores and eosinophil concentrations within and between groups.

RESULTS:

30 subjects were enrolled and completed treatment. The mean age for both groups was 30 years (range 15-52). Twenty-four subjects were male (80%). The eosinophil concentration proximally and distally did not change significantly in either group post-treatment. The dysphagia score did improve significantly in both groups when comparing the baseline score to the week 16 (omalizumab group p<0.0001, placebo group p=0.02). However, the improvement in dysphagia score was not significant between groups (see table). The serum IgE level increased significantly in the omalizumab group between pre and post-treatment (p<0.0001) confirming drug effect.

CONCLUSION:

There was no improvement in the eosinophil infiltration with placebo or omalizumab treatment in EoE patients. Dysphagia scores improved similarly with both omalizumab and placebo. Omalizumab does not appear to be effective in the treatment of EoE.