Novo Nordisk has completed its phase 2a clinical trial of monlunabant, an oral cannabinoid receptor 1 (CB1) inverse agonist, for obesity treatment.
The study included 243 participants with obesity and metabolic syndrome, testing daily doses of 10 mg, 20 mg, and 50 mg over 16 weeks. All doses of monlunabant led to significant weight loss compared to placebo. Participants on the 10 mg dose lost an average of 7.1 kg, while the placebo group saw a 0.7 kg reduction.
The trial highlighted common adverse effects, particularly gastrointestinal issues, which were generally mild to moderate and dose dependent. Notably, neuropsychiatric side effects, including anxiety, irritability, and sleep disturbances, were also more frequent at higher doses, though no serious adverse events were reported.
Novo Nordisk plans to launch a phase 2b trial in 2025 to further explore dosing and assess the long-term safety of monlunabant, with a focus on its side effect profile.
Last year, the European Medicines Agency (EMA) flagged weight loss drugs for potential mental health risks, prompting a review of Novo Nordisk's diabetes drug Ozempic for possible links to suicide ideation and self-harm. After two reports from Iceland, the EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) investigated whether these events were related to Ozempic and expanded the review to include other GLP-1 drugs like Saxenda and Wegovy.
