The Triumph-1 (NCT05929066) extension data puts a hard number on retatrutide’s ceiling: 30.3% mean weight reduction at 104 weeks on the 12-mg dose, building on the 28.3% at the 80-week primary endpoint. That’s the magnitude most clinicians associate with bariatric surgery, not a pill or injection.
Lilly expanded the case at ADA’s 2026 Scientific Sessions. Nested basket studies within Triumph-1 showed a 73.1% reduction on the WOMAC pain subscale in knee osteoarthritis patients, and sleep apnea patients dropped from 58.6 to 36.1 events per hour on the apnea-hypopnea index. Cardiovascular surrogate markers moved favorably too: triglycerides down 41%, non-HDL cholesterol down 24.2%, systolic blood pressure down 12.3 mmHg at 80 weeks.
The Transcend-T2D-1 diabetes data filled out the metabolic picture: up to 90% of patients hit the ADA’s A1C target of below 7.0%, and 46% reached normoglycemia, defined as A1C below 5.7%.
I read the Transcend-T2D-1 manuscript’s safety table this week. In the 403-participant trial, seven patients in the active arm experienced arrhythmias and three had major cardiovascular complications; zero in placebo. Lilly’s response leans on the surrogate data: favorable lipid trends will “manifest to hopefully reduction in cardiovascular risk.” That’s a prospective argument, not a measured outcome. FDA’s review of incretin obesity drugs has historically accepted post-market cardiovascular commitments rather than pre-approval outcomes trials — but a named arrhythmia count in a small diabetes cohort is a data point the agency won’t bracket away. Whether that signal shadows retatrutide’s full ADA obesity data package when the NDA arrives is the central regulatory question.
Lilly is targeting five approved obesity medicines by decade’s end. NDA timing is the date to track.
Rebecca Lauren