Vanda Pharmaceuticals’ tradipitant cleared a major Phase 2 hurdle tied to preventing nausea and vomiting associated with GLP-1 receptor agonists, but U.S. FDA review outcomes are constraining its broader expansion. Separately, the FDA again declined tradipitant in gastroparesis, leaving the company with limited regulatory path for that indication. The mixed clinical and regulatory picture highlights how investigational NK1 receptor antagonism can show utility in one symptom domain while still failing to meet evidence thresholds in other disease settings. Vanda’s next steps include Phase 3 planning in the anti-GLP-1 nausea/vomiting space. The divergence also increases attention on trial design specifics, endpoint selection, and patient populations for functional GI disorders where placebo response and measurement variability are recurring issues.