Vanda Pharmaceuticals Inc. (VNDA) just released clinical trial results that could make GLP-1 drugs a lot more tolerable for people who struggle with their notorious side effects. The company announced Monday that its drug tradipitant successfully prevented much of the nausea and vomiting that Novo Nordisk's (NVO) Wegovy causes in patients.

The trial studied 116 healthy adults who were overweight or obese. Wegovy, a GLP-1 receptor agonist that's become wildly popular for weight loss, works incredibly well when people can stick with it. The problem is that many can't, because the gastrointestinal side effects are severe enough to make people quit early.

Why This Matters

Here's the economic reality: patients abandon treatments that could deliver 15-20% weight loss with sustained use, along with significant health improvements. Insurance companies waste money on prescriptions that patients stop taking before seeing benefits, then continue paying for obesity-related complications and hospitalizations down the line. It's expensive for everyone involved.

The current real-world discontinuation rates for GLP-1 drugs sit between 30-50%, often before patients even reach therapeutic doses. That's a massive problem for a market that's already topped $50 billion through the first nine months of 2025.

The Trial Results

Vanda's study pretreated participants with either tradipitant or placebo before giving them a 1 mg injection of Wegovy. That's a dose that normally requires nine weeks of gradual titration to reach, which gives you a sense of how aggressive the test was.

The results were striking. Only 29.3% of tradipitant-treated participants experienced vomiting compared to 58.6% on placebo. That's a 50% relative reduction in a side effect that drives many people off these medications entirely.

The study also hit its key secondary endpoint, measuring the proportion of participants with both vomiting and significant nausea. In the tradipitant group, 22.4% experienced both symptoms versus 48.3% on placebo.

Tradipitant showed a favorable safety profile consistent with previous studies, with no new safety concerns emerging. The drug has already demonstrated similar efficacy in motion sickness trials, where it reduced vomiting by more than 50% across studies involving over 800 people.

What Happens Next

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

The company is now evaluating the fastest path toward regulatory approval. A Phase 3 program is expected to start in the first half of 2026. If tradipitant works as an adjunct therapy in the rapidly expanding GLP-1 market, it could transform how patients experience these treatments and dramatically improve adherence rates.

Stock Movement: Vanda Pharmaceuticals shares jumped 16.24% to $5.11 at the time of publication on Tuesday.