Vanda Pharmaceuticals has announced positive topline results from its randomised controlled study evaluating tradipitant, an oral neurokinin-1 (NK-1) receptor antagonist, for preventing nausea and vomiting associated with GLP-1 receptor agonist Wegovy in overweight and obese adults.

The study successfully met its primary endpoint. Nearly 30 percent of patients treated with tradipitant experienced vomiting, compared to over 58 percent in the placebo group, representing a 50 percent relative reduction. The trial also achieved its key secondary endpoint, with 22.4 percent of patients in the tradipitant arm reporting vomiting with significant nausea versus 48.3 percent on placebo.

The double-blind, placebo-controlled trial studied 116 healthy overweight or obese adults (BMI 25–40 kg/m²) without prior GLP-1 agonist experience. Participants were pre-treated with 85 mg twice daily or placebo for one week before administering a 1 mg injection of Wegovy – a dose that normally takes nine weeks of titration to reach under current prescribing guidelines.  Treatment continued for an additional week post-dosing, with outcomes measured through daily self-reported assessments.

Tradipitant demonstrated a favourable safety profile consistent with previous studies, with no new safety signals observed.   

"These results demonstrate tradipitant's potential to mitigate GLP-1 induced nausea and vomiting, which are key contributors to the 30-50 percent real-world discontinuation rates for GLP-1 agonists, often before therapeutic doses are reached," said Mihael H. Polymeropoulos, President, CEO and Chairman, Vanda.

"Tradipitant's effect in reducing nausea and vomiting could significantly improve GLP-1 agonist adherence, enabling more people to receive the full therapeutic benefit,” he added.

The company noted that the observed efficacy is consistent with tradipitant's demonstrated performance in motion sickness in multiple studies, where it reduced vomiting by more than 50 percent in randomised studies with over 800 individuals.

Vanda believes tradipitant could emerge as a potentially transformative adjunct in the rapidly expanding global GLP-1 agonist market, which surpassed USD 50 billion in the first nine months of 2025.

Vanda plans to initiate a Phase III programme in the first half of 2026, advancing tradipitant toward regulatory approval for this unmet clinical need.