Obesity drug manufacturer Eli Lilly has announced positive topline results from its Phase III trial of the next-generation GLP-1 drug retatrutide.
The once-weekly, triple-hormone receptor agonist delivered significant weight loss across doses, with the highest dose resulting in 28.3% weight loss during the 80-week period.
According to Lilly's statement, around 45% of the 2500 patients in the TRIUMPH Phase III trial achieved 30% or more weight loss.
This places it ahead of Lilly's current blockbuster GLP-1, Zepbound, which achieved 20-22% weight loss.
"Obesity is a chronic disease and people living with obesity deserve treatment options that match the complex biology of their neurometabolic disease," said Dr Ania Jastreboff, Professor of Medicine & Pediatrics (Endocrinology) at the Yale School of Medicine, Director of the Yale Obesity Research Center (Y-Weight) and lead investigator.
"It was impressive to see that every dose of retatrutide resulted in clinically meaningful weight reduction for nearly all participants and people with severe obesity on the highest dose lost on average 30% of their body weight during two years."
Importantly, treatment with retatrutide not only resulted in robust weight reduction, but also in clear improvements in assessed cardiometabolic health measures.
However, the drug did appear to cause higher rates of gastrointestinal side effects such as nausea and diarrhoea, particularly at the highest dosage.
Lower doses were associated with fewer side-effect discontinuations.
"TRIUMPH-1 highlights the importance of options and the potential for retatrutide to help people across various stages of their obesity journey," added Dr Kenneth Custer, Executive Vice President and President, Lilly Cardiometabolic Health.
"From the 4 mg dose, reaching nearly 20% weight loss with one escalation step, to the 12 mg dose that delivered a level of weight loss long associated with bariatric surgery, retatrutide offers the potential for a patient-centric approach to obesity."
Together with Zepbound and Foundayo, retatrutide could build on Lilly's commitment to match treatments to the needs and preferences of patients.
The results bring Lilly a step closer to filing for approval of the weekly injection.