Collins, Margaret H.

INTRODUCTION: Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease for which there is an unmet clinical need for new therapies. The safety and efficacy of budesonide oral suspension (BOS) for the treatment of EoE has been demonstrated in a previous phase 2 study. The current phase 3 study evaluated the efficacy and safety of BOS in a large cohort of patients with EoE. METHODS: This randomized, double-blind, placebo-controlled trial (SHP621-301; NCT02605837) investigated the safety and efficacy of BOS in patients (11–55 years) with EoE and dysphagia. Patients were randomized 2:1 to 2.0 mg BOS or placebo twice daily (b.i.d.) for 12 weeks (Figure 1). Co-primary endpoints were histologic (peak eosinophil count ≤6 eosinophils/high-powered field [eos/hpf]) and dysphagia symptom (≥30% decrease in symptoms as measured by the Dysphagia Symptom Questionnaire [DSQ]) responses after 12 weeks of therapy. Secondary endpoints included change in DSQ score and change in EoE Endoscopic Reference Score (EREFS) from baseline to final treatment period. Safety was also assessed. RESULTS: A total of 322 patients were randomized (BOS, n = 215; placebo, n = 107), of whom 318 patients received at least one dose of double-blind therapy (BOS, n = 213; placebo, n = 105) (Table 1). The primary outcomes were achieved, with significantly more histologic and symptom responders in the BOS-treated than the placebo-treated group (53.1% vs 1.0%, P < 0.001; 52.6% vs 39.1%, P = 0.024, respectively; Figure 2). Improvements in mean DSQ score from baseline to week 12 were significantly greater in the BOS group (n = 197) than the placebo group (n = 89) (−13.0 vs −9.1; P = 0.015). Similarly, improvements in mean EREFS scores were significantly greater with BOS (n = 202) than placebo (n = 93) (−4.0 vs −2.2; P < 0.001). In total, 61.0% of patients reported a treatment-emergent adverse event (TEAE) (BOS, 61.0%; placebo, 61.0%). Only 2.5% of patients experienced a TEAE leading to dose discontinuation (BOS, 1.4%; placebo, 4.8%). Few patients had severe or serious TEAEs on BOS or placebo. No life-threatening TEAEs were reported. CONCLUSION: This phase 3 trial demonstrated the efficacy of BOS as induction therapy for EoE. BOS resulted in significant improvements in histologic, symptomatic and endoscopic endpoints compared with placebo. The majority of TEAEs were mild to moderate and comparable between placebo and BOS. A double-blind, placebo-controlled maintenance study (SHP621-302) is ongoing.

Budesonide oral suspension (BOS) is a novel topical corticosteroid, which has been shown to improve symptoms and endoscopic appearance, and reduce peak eosinophil counts in patients with eosinophilic esophagitis (EoE). This trial evaluated the effect of BOS or placebo on the severity (grade) and extent (stage) of 8 histopathologic features observed in EoE, using the validated eosinophilic esophagitis histologic scoring system (EoE HSS). Patients with EoE aged 11 to 40 years with dysphagia were randomized to receive either BOS (2.0 mg twice daily) or placebo for 12 weeks. Mean (SD) EoE HSS grade and stage total scores at baseline for placebo and BOS groups were: grade, 0.42 (0.16) and 0.49 (0.14), respectively; stage: 0.38 (0.14) and 0.46 (0.11), respectively. These scores significantly decreased (improved) from baseline for patients receiving BOS versus placebo (grade: least squares mean change [SE]: placebo vs. BOS, −0.04 [0.03] vs. −0.24 [0.02]; P<0.0001; stage: −0.01 [0.02] vs. −0.19 [0.02]; P<0.0001). EoE HSS total scores improved for 6 of the 8 and 5 of the 8 histopathologic features for grade and stage, respectively, versus placebo. Change in EoE HSS total scores correlated moderately but significantly with change in endoscopic severity (endoscopic reference score; grade: R=0.5349; stage: R=0.5416; both P<0.0001). Change in EoE HSS stage total score correlated weakly with change in Dysphagia Symptom Questionnaire scores (grade: R=0.1925; P=0.0740; stage: R=0.2135; P=0.0471). These data demonstrate that the EoE HSS is a valuable endpoint of treatment response in randomized clinical trials and should be considered for future trials for EoE.

AbstractEosinophil-associated diseases (EADs) are rare, heterogeneous disorders characterized by the presence of eosinophils in tissues and/or peripheral blood resulting in immunopathology. The heterogeneity of tissue involvement, lack of sufficient animal models, technical challenges in working with eosinophils, and lack of standardized histopathologic approaches have hampered progress in basic research. Additionally, clinical trials and drug development for rare EADs are limited by the lack of primary and surrogate endpoints, biomarkers, and validated patient-reported outcomes. Researchers with expertise in eosinophil biology and eosinophil-related diseases reviewed the state of current eosinophil research, resources, progress, and unmet needs in the field since the 2012 meeting of the NIH Taskforce on the Research of Eosinophil-Associated Diseases (TREAD). RE-TREAD focused on gaps in basic science, translational, and clinical research on eosinophils and eosinophil-related pathogenesis. Improved recapitulation of human eosinophil biology and pathogenesis in murine models was felt to be of importance. Characterization of eosinophil phenotypes, the role of eosinophil subsets in tissues, identification of biomarkers of eosinophil activation and tissue load, and a better understanding of the role of eosinophils in human disease were prioritized. Finally, an unmet need for tools for use in clinical trials was emphasized. Histopathologic scoring, patient- and clinician-reported outcomes, and appropriate coding were deemed of paramount importance for research collaborations, drug development, and approval by regulatory agencies. Further exploration of the eosinophil genome, epigenome, and proteome was also encouraged. Although progress has been made since 2012, unmet needs in eosinophil research remain a priority.Review on eosinophil biology and eosinophil-related disorders (2012–2017) with a focus on continued unmet needs in eosinophil-associated diseases.