Eloralintide Plus Tirzepatide Yields Up to 23.3% Mean Weight Loss in Phase 2b Trial

In a company press release, Eli Lilly reported that EloraTZP, an investigational combination of eloralintide (Eli Lilly) and tirzepatide (Zepbound, Mounjaro; Eli Lilly), produced mean weight loss of up to 23.3% at 48 weeks in adults with obesity or overweight and type 2 diabetes. The phase 2b results were presented at the 62nd Annual Meeting of the European Association for the Study of Diabetes in Milan, Italy.

Eloralintide is a once-weekly selective amylin receptor agonist; tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. According to Lilly, the combination was designed to activate GIP, GLP-1, and amylin pathways with minimal calcitonin receptor activity.

The double-blind, placebo-controlled trial (NCT06603571) randomized 367 participants in the US and Argentina to placebo, eloralintide, tirzepatide, or EloraTZP, with the 2 agents given as separate injections. The primary endpoint was percent change in body weight with EloraTZP vs placebo; comparisons with tirzepatide were secondary. From a mean baseline of 105.4 kg, weight fell 13.2% to 23.3% across 4 EloraTZP dose combinations, with the largest reduction for eloralintide 9mg plus tirzepatide 15mg. Weight fell 14.8% with tirzepatide 15mg, up to 12.3% with eloralintide alone, and 3.0% with placebo. From a baseline of 8.1%, A1C fell by up to 2.9% with EloraTZP vs 2.4% with tirzepatide 15mg. Results reflect the efficacy estimand, which assumes all participants remained on treatment; the release did not report statistical testing for comparisons with tirzepatide.

Gastrointestinal adverse events were most common, generally mild or moderate, occurred primarily during dose escalation, and were more frequent with combination therapy. Discontinuations due to adverse events were 10.8% to 27.0% with EloraTZP, 0% to 10.8% with eloralintide, 2.9% with tirzepatide, and 16.7% with placebo.

Lilly plans to begin phase 3 trials of an EloraTZP co-formulation by the end of 2026 using an optimized escalation schedule. Eloralintide is also in phase 3 trials as a single agent for obesity. The findings are from a conference presentation; the release did not cite a peer-reviewed publication.

Source: Eli Lilly and Company. Lilly's EloraTZP (combination of eloralintide and tirzepatide) delivered greater weight loss and A1C reduction vs. tirzepatide 15 mg in adults with obesity and type 2 diabetes. Press release. Eli Lilly and Company; September 30, 2026. Accessed October 1, 2026.