Novo Nordisk’s UBT251 Yields 19.7% Weight Loss, Challenging Eli Lilly’s Retatrutide
Novo Nordisk’s UBT251 delivered 19.7% mean weight loss (17.5 kg) versus 2% placebo in a 24-week Chinese phase 2 trial using 2–6 mg weekly doses. These results position UBT251 as a challenger to Eli Lilly’s retatrutide and may pressure Lilly’s share in the obesity drug market.
1. China Phase 2 Trial Results
Novo Nordisk and United Laboratories conducted a Chinese phase 2 trial of UBT251 in overweight or obese patients with a mean baseline weight of 92.2 kg. Participants received once-weekly injections of 2 mg, 4 mg or 6 mg doses, and the highest dose group achieved a 19.7% mean weight reduction (17.5 kg) versus 2.0% (1.6 kg) for placebo after 24 weeks.
2. Competitive Implications for Eli Lilly
UBT251 is designed to compete directly with Eli Lilly’s retatrutide, marking a key test of market dynamics in the obesity treatment space. A license agreement signed in March 2025 involves over $2 billion in upfront and milestone payments, underscoring the strategic importance of UBT251 in challenging Lilly’s market leadership.
3. Safety and Tolerability
Across all dose groups, UBT251 showed a safety profile consistent with incretin-based therapies, with most adverse events being gastrointestinal in nature and rated mild to moderate. Incidence declined over time, suggesting a manageable tolerability profile similar to other GLP-1/GIP/glucagon agonists.
4. Next Steps in Global Development
Novo Nordisk has initiated a global phase 1b/2a trial of UBT251 in approximately 330 participants, with topline data expected in 2027, and plans a phase 2 type 2 diabetes trial in the second half of 2026. Based on the Chinese results, a phase 3 trial in China is also under planning, with detailed data to be presented at a medical congress later this year.