Genta, Robert M.

Abstract Eosinophilic esophagitis (EoE), gastritis (EG), and/or duodenitis (EoD) are associated with accumulation and activation of eosinophils and mast cells in the esophagus, stomach, and/or duodenum, respectively. Lirentelimab (AK002), an antibody against siglec-8, depletes eosinophils and inhibits mast cells. We performed an open-label extension (OLE) study of subjects who completed ENIGMA (a randomized, double-blind, placebo-controlled phase 2 study of lirentelimab in adults with symptomatic, biopsy-confirmed EG and/or EoD, with or without EoE) to evaluate long-term responses. Methods Subjects who received 4 monthly infusions of lirentelimab or placebo during ENIGMA (n = 59) were eligible for the OLE; they received monthly, escalating doses of lirentelimab (0.3 or 1 mg/kg escalating to 3 mg/kg). Symptoms were assessed weekly using an electronic daily patient-reported outcome questionnaire and total symptom scores (TSS) were calculated. Patients underwent upper endoscopy with biopsy at screening and at the end of ENIGMA (day 99, week 16, blinded); in the OLE, endoscopies were performed on day 323 (30 weeks after the first dose in the OLE). Histopathology was assessed by a single pathologist. Results Fifty-eight subjects entered the OLE; 45 completed ≥52 weeks lirentelimab (including exposure during ENIGMA) and 29 completed 70 weeks. Mean TSS improved through week 70 (Figure 1). Subjects receiving 70 weeks lirentelimab (ENIGMA+OLE) had further improvements in TSS from baseline (mean reductions: 68% at weeks 29–30, 70% at weeks 51–52, 75% at weeks 69–70). Symptom scores (abdominal pain, nausea, vomiting, early satiety, appetite loss, abdominal cramping, bloating, diarrhea) decreased significantly from baseline. Treatment response was not associated with concomitant EoE. The most common adverse event was mild to moderate infusion-related reactions, usually with the first infusion. Conclusion In the OLE of the ENIGMA study, patients with EG and or EoD (with or without concomitant EoE) who received lirentelimab had sustained tissue eosinophil depletion and significant long-term symptom improvement. Symptoms continued to improve with duration of treatment. Lirentelimab appears to be a promising targeted treatment for EG and/or EoD.

Abstract Although the prevalence of eosinophilic gastrointestinal disorders (EGIDs) is increasing, there is evidence that eosinophilic gastritis and/or duodenitis (EG/EoD) are underdiagnosed. Patients with EG/EoD often present with chronic, non-specific gastrointestinal (GI) symptoms, similar to patients with functional GI disorders. We hypothesized that systematic evaluation, including multiple esophageal, gastric and duodenal biopsies, of patients with chronic GI symptoms might reveal a high rate of gastroduodenal eosinophila, with or without eosinophilic esophagitis (EoE). Methods We performed a prospective multi-center study of patients with non-specific GI symptoms for ≥6 months, from 20 sites. Patients completed a questionnaire assessing abdominal pain, abdominal cramping, early satiety, bloating, nausea, vomiting, diarrhea, and loss of appetite. Those with daily average symptom severity scores ≥3/10 for any single symptom underwent esophagogastroduodenoscopy (EGD) with collection of 4 esophageal (EoE), 8 gastric, and 4 duodenal biopsies, analyzed by central pathologists. Histologic criteria for EoE was ≥15eos/hpf in ≥1 esophageal site and for EG/EoD was peak eosinophil counts ≥30/hpf in ≥5 gastric hpfs and/or 3 duodenal hpfs—criteria used in randomized trials. Results Of 556 patients screened, 405 (73%) met symptom criteria and underwent EGD; 181 patients (45%, mean age 45, 73% female) who underwent EGD met the histologic criteria for EG/EoD, and of these, 7% also had EoE diagnosed. Overall 2% met histologic criteria for EoE alone. Of patients who met the histologic criteria for EG/EoD, 93% were previously diagnosed with gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), or functional dyspepsia (FD) (Figure 1). The average duration of GI symptoms in the screened population as well as those that met histologic criteria for EG/EoD was 11 years. Conclusion Forty-five percent of patients with moderate-to-severe GI symptoms who underwent EGD met histologic criteria for EG/EoD. Over 90% of these patients had previously been diagnosed with GERD, IBS, and/or FD, and had minimal overlap with EoE. EGD with systematic gastroduodenal biopsies, and intentional evaluation for tissue eosinophilia, should be performed in patients with chronic GI symptoms. Accurate diagnosis of EG/EoD is required for appropriate, targeted treatment and improved outcomes of patients with moderate-to-severe GI symptoms.