Tirzepatide's SURMOUNT program (2022-2023)
Eli Lilly's dual GLP-1/GIP agonist tirzepatide showed about 21% mean weight loss at 72 weeks in its pivotal SURMOUNT-1 trial and won U.S. approval as Zepbound in November 2023.
Zepbound became a top-selling U.S. weight-loss drug, setting roughly 20% weight loss as the efficacy benchmark for the drug class.
Dual GLP-1/GIP agonism became the leading mechanism in obesity pharmacotherapy, pushing rivals to develop follow-on candidates.
Olatorepatide's 19.3% at 48 weeks, with no plateau, sits in Zepbound's range. Its market test is whether it holds that efficacy over longer treatment while keeping the tolerability edge.
