The Efficacy of Tradipitant in Patients With Diabetic and Idiopathic Gastroparesis in a Phase 3 Randomized Placebo-Controlled Clinical Trial.

BACKGROUND: Neurokinin receptor 1 antagonists are effective in reducing nausea and vomiting in chemotherapy-induced emesis. We investigated the safety and efficacy of tradipitant, a neurokinin receptor 1 antagonist, in patients with idiopathic and diabetic gastroparesis. METHODS: A total of 201 adults with gastroparesis were randomly assigned to oral tradipitant 85 mg (n = 102) or placebo (n = 99) twice daily for 12 weeks. Symptoms were assessed by a daily symptom dairy, Gastroparesis Cardinal Symptom Index scores, and other patient-reported questionnaires. Blood levels were monitored for an exposure-response analysis. The primary outcome was change from baseline to week 12 in average nausea severity, measured by daily symptom diary. RESULTS: The intention-to-treat (ITT) population did not meet the prespecified primary endpoint at week 12 (difference in nausea severity change drug vs placebo; P = .741) or prespecified secondary endpoints. Post hoc analyses were performed to control for drug exposure, rescue medications, and baseline severity inflation. Subjects with high blood levels of tradipitant significantly improved average nausea severity beginning at early time points (weeks 2-4). In post hoc sensitivity analyses, tradipitant treatment demonstrated strengthened effects, with statistically significant improvements in nausea at week 12. CONCLUSIONS: Although tradipitant did not reach significance in the ITT population, a pharmacokinetic exposure-response analysis demonstrated significant effects with adequate tradipitant exposure. When accounting for confounding factors such as baseline severity inflation and rescue medication, a statistically significant effect was also observed. These findings suggest that tradipitant has potential as a treatment for the symptom of nausea in gastroparesis. (ClincialTrials.gov, Number: NCT04028492).

Enrichment of Patients With Ehlers Danlos Syndrome in Idiopathic Gastroparesis-A Gene Set Enrichment Analysis.

INTRODUCTION: Ehlers Danlos syndrome (EDS) is a heritable disorder of the connective tissue usually inherited as an autosomal dominant trait. We observe an enrichment of EDS cases in a gastroparesis clinical study. METHODS: We explored the frequency of EDS cases in 2 consecutive gastroparesis clinical studies. To explore the genetic surrogates of EDS, we have performed whole-genome sequencing analysis and we focused the analyses on the frequencies of consequential variants in core EDS genes. RESULTS: We report a significant enrichment of EDS cases in a set of patients with gastroparesis (14/686 vs 1/5,000 OR 104 (confidence interval 13.7-793.3) P value <0.0001). We report a significant enrichment of variants in EDS genes in patients with idiopathic gastroparesis. DISCUSSION: The enrichment may be suggestive of converging pathways at the heart of etiology or predisposing patients to EDS with gastroparesis.