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The FDA’s Dec. 30 approval of Vanda Pharmaceuticals’ Nereus (tradipitant) adds a rare new option to a category that has leaned for decades on older anticholinergics and antihistamines, including the scopolamine patch and over-the-counter products such as meclizine and dimenhydrinate. In reporting on the decision, Reuters noted the approval as the first new FDA-cleared treatment for motion-induced vomiting in more than 40 years. The prescription scopolamine patch, Transderm Scōp, lists its initial U.S. approval as 1979.
For Vanda, the motion-sickness label may be the smaller prize. The company is already testing tradipitant, an NK-1 receptor antagonist, for a potentially larger market: preventing the nausea and vomiting that can push some patients off GLP-1 drugs such as Ozempic and Wegovy.
Even bullish analysts have described the motion-sickness opportunity as roughly a $100 million annual peak, while GLP-1 medicines have become one of the biggest drug classes in the world. GLP-1 agonists are among the best-selling drug class in recent memory.
GLP-1 nausea is common in many patients. In the STEP obesity trials of semaglutide 2.4 mg, gastrointestinal side effects were common, especially early in treatment and after dose increases. In one summary of the data, nausea was reported in 44% of participants and vomiting in 24%. Trial participants often persist through these effects with dose escalation schedules and counseling, but the day-to-day reality in clinics is that some patients stop rather than ride it out.
Real-world data show just how often persistence breaks down. A Truveta analysis of adults with overweight or obesity who started GLP-1 therapy between 2018 and 2023 found that discontinuation within one year was 64.8% among patients without type 2 diabetes. The same report also flagged moderate or severe gastrointestinal side effects as strongly associated with a higher likelihood of stopping. (The underlying manuscript is also available as a full-text preprint describing similar discontinuation patterns.)
Surveys point in the same direction on why patients quit. In a real-world, cross-sectional survey of physicians and their patients with type 2 diabetes who had discontinued GLP-1 receptor agonists, the authors reported that tolerability issues were frequently cited, including nausea and vomiting (Sikirica et al., 2017).
Cost and coverage can matter at least as much as side effects, but GI intolerance is one of the few drivers that is both common and potentially fixable with better supportive care or add-on therapy.
That is where tradipitant comes in. Nereus blocks the neurokinin-1 (NK-1) receptor, part of a pathway long associated with nausea and vomiting. NK-1 antagonists are an established antiemetic class in oncology supportive care, where preventing chemotherapy-induced nausea and vomiting is a core use case. Vanda is betting that the same biology can translate into improved tolerability for GLP-1 patients, without interfering with the metabolic effects people are taking GLP-1s for.
Early data support the hypothesis. In a randomized controlled study announced Nov. 17, 2025, Vanda reported that tradipitant cut vomiting rates roughly in half among participants given a 1 mg Wegovy injection—a dose that normally takes nine weeks of titration to reach. Only 29.3% of tradipitant-treated participants experienced vomiting compared to 58.6% on placebo (p=0.0016). The company anticipates initiating a Phase III program in the first half of 2026.
The commercial logic is straightforward: GLP-1 outcomes depend on staying on therapy, particularly for obesity. In a STEP 1 extension study, participants who stopped semaglutide regained a large share of the weight they had lost over the next year (Wilding et al., 2022). That clinical reality helps explain why drugmakers, payers, and employers all care about adherence, even if they disagree on who should pay for it.
Still, the “dropout problem” is not solely a side-effect story. Real-world persistence has varied by time period, indication, insurance coverage, and supply constraints. Claims-based reporting has shown persistence improving in more recent cohorts for some obesity GLP-1s, alongside changes in access and availability. Any add-on antiemetic will be competing not just with nausea itself, but with price, prior authorizations, intermittent shortages, and patient expectations about how long they “need” to stay on treatment.
The next question, then, is whether tradipitant can demonstrate meaningful benefit in the setting that matters most: real-world GLP-1 users who are on the fence because of nausea, vomiting, or both. If future trials can show fewer discontinuations, fewer down-titrations, or faster achievement of maintenance doses, that is a clear value proposition. If the effect is modest, or limited to a subset of patients, the opportunity could shrink quickly, especially given the availability of generic antiemetics and the pressure payers face to control total GLP-1 spending.
Filed Under: Gastroenterology
