Abstract
BACKGROUND & AIMS Treatments are needed for gastroparesis; antagonists of tachykinin receptor 1 (TACR1, also called NK1R) can reduce symptoms of nausea and vomiting. We investigated the safety and efficacy of tradipitant, an antagonist of NK1R, in patients with idiopathic or diabetic gastroparesis. METHODS We performed a double-blind trial of 152 adults with gastroparesis at 47 sites in the United States from November 2016 through December 2018. Participants were randomly assigned to groups given oral tradipitant 85 mg (n = 77) or placebo (n = 75) twice daily for 4 weeks. Symptoms were assessed by a daily symptom dairy, Gastroparesis Cardinal Symptom Index scores, and other patient-reported questionnaires. The primary outcome from the intent-to-treat analysis was change from baseline to week 4 in average nausea severity, measured by the Gastroparesis Core Symptom Daily Diary. RESULTS Patients receiving tradipitant had a significant decrease in nausea score (reduction of 1.2) at week 4 compared with placebo (reduction of 0.7) (P = .0099) and a significant increase in of nausea-free days at week 4 (28.8% increase on tradipitant vs 15.0% on placebo; P = .0160). Patients with nausea and vomiting at baseline (n = 101) had an even greater decrease in nausea in when given tradipitant (reduction of 1.4) compared with those given placebo (reduction of 0.4) (P < .0001), as well as an increase in nausea-free days at week 4 (32.3% improvement on tradipitant vs 7.6% on placebo; P = .0003). The average nausea score was 1 or less at week 4 in 32.9% of patients given tradipitant compared with 11.8% of patients given placebo (P = .0013). A greater than 1-point improvement in Gastroparesis Cardinal Symptom Index score was observed in 46.6% of patients given tradipitant compared with 23.5% of patients given placebo (P = .0053). CONCLUSIONS Tradipitant resulted in statistically and clinically meaningful improvements in nausea and reduced vomiting, compared with placebo, in patients with idiopathic or diabetic gastroparesis. ClinicalTrials.gov, Number: NCT02970968.
