Eli Lilly weight loss drug data supports long-term obesity market position, says UBS Proactive uses images sourced from Shutterstock
Eli Lilly and Co (NYSE:LLY) last week reported late-stage weight loss data for retatrutide, which UBS analysts highlighted showed “solid strong weight loss efficacy” and were broadly in line with expectations ahead of further detail at the American Diabetes Association meeting.
UBS highlighted that the Phase III data in obesity showed a clear dose-response across 4mg to 12mg, with the highest dose producing about 28% weight loss at 80 weeks in patients with a body mass index (BMI) of 30 or higher.
The analysts noted that prior tirzepatide studies included patients with BMI thresholds of 27 or higher and shorter follow-up of up to 72 weeks, making direct comparisons imperfect.
In an extension cohort of patients with BMI above 35, weight loss in the highest-dose group increased from 28% at 80 weeks to 30% at 104 weeks. UBS noted that this was in line with expectations and consistent with earlier Phase III data in a different obesity population, which had shown weight loss of roughly 28% to 29% at around 68 weeks.
The firm described the overall efficacy profile as strong, adding that Eli Lilly appears to be positioning retatrutide primarily for patients with BMI above 35, while noting that trials were conducted in a broader BMI 30+ population.
UBS also suggested the drug could maintain differentiation versus expected generic competition in the obesity market later in the decade, which they estimate would likely deliver up to around 15% weight loss.
On safety and tolerability, UBS said the profile was broadly consistent with expectations. At the highest dose, nausea was reported in 42% of patients, diarrhea in 32%, and vomiting in 25%. The analysts noted these rates were numerically higher than tirzepatide but broadly in line with Wegovy. Discontinuation rates were 11% in the high-dose group compared with 5% on placebo, a level UBS said was within the typical 7% to 10% range seen across GLP-1 therapies.
Lower-dose cohorts showed numerically lower discontinuation rates than placebo, while still achieving about 19% weight loss after a single dose escalation step. UBS believes that this combination of efficacy and tolerability support retatrutide’s positioning as a potentially differentiated obesity treatment in a post-generic market.
Looking ahead to the ADA presentation, UBS wrote that additional focus will be on tolerability and safety metrics, including heart rate effects. The analysts noted earlier Phase II data showed an increase of about 6 to 7 beats per minute with the GGG mechanism, compared with roughly 2 to 3 beats per minute for tirzepatide, but described these effects as well understood within the incretin class.