Scientific Sessions attendees will get the first combined review of four global trials of tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist in development for the treatment of type 2 diabetes. The first twin incretin showed meaningful superiority to placebo and to existing agents in four Phase 3 randomized controlled trials. Tirzepatide showed mean A1C reductions up to 2.6% and dose-dependent body weight loss between 8% and 14% in four SURPASS trials that will be reported at the Scientific Sessions.
“These are unprecedented clinical results,” said Julio Rosenstock, MD, Director of the Dallas Diabetes Research Center at Medical City and Principal Investigator for SURPASS-1. “The combined outcome of A1C reductions in the 2% range plus weight loss of around 10% or more of body weight has not generally been seen with glucose-lowering agents in type 2 diabetes.”
New, detailed results of the four SURPASS clinical trials will be presented at the 81st Scientific Sessions in multiple abstracts. A dedicated symposium, Next Chapter in Incretin-Based Therapies—Tirzepatide, a Novel Dual GIP/GLP-1 Receptor Agonist—Results from the First Phase 3 SURPASS Clinical Trials, will provide a global perspective of the trials. The two-hour session begins at 8:00 a.m. ET Tuesday, June 29.
The global SURPASS clinical trial program has enrolled more than 13,000 participants with type 2 diabetes across 10 clinical trials, including five pivotal trials. The trials tested three tirzepatide doses (5 mg, 10 mg, and 15 mg) against placebo or active comparators. SURPASS-1 compared tirzepatide to placebo; SURPASS-2 compared tirzepatide to 1 mg semaglutide; SURPASS-3 compared tirzepatide to insulin degludec; and SURPASS-5 compared tirzepatide to placebo add-on to titrated insulin glargine. The trials ran for 40 or 52 weeks.
The primary endpoint for the trials was the change in A1C from baseline. Secondary endpoints included change in body weight; change in fasting serum glucose; percentage of participants achieving an A1C target <7%, <6.5%, and <5.7%; percentage of participants achieving weight loss of ≥5%, ≥10%, and ≥15%; and rate of hypoglycemic events.
The four trials to be reported in the session met all of the primary and secondary endpoints, Dr. Rosenstock said. Tirzepatide showed substantially greater reductions in A1C and body weight vs. placebo and all active comparators.
Tirzepatide participants had low frequency of documented hypoglycemic events (<54 mg/dL) in most trials, despite the robust A1C reductions. As expected, the most commonly reported adverse events were gastrointestinal-related, including nausea, diarrhea, and vomiting.
“The glucose-lowering and weight reductions of this dual incretin receptor agonist are unprecedented, but we have not seen all the results yet. Please join us on June 29 to see the complete picture,” Dr. Rosenstock said. “I am sure it will be one of the most attended symposia of the ADA meeting this year.”