Forget retatrutide, Eli Lilly has something new for weight loss
Eli Lilly is combining tirzepatide with the amylin agonist eloralintide. In a Phase 2b study in people with type 2 diabetes, participants lost up to 23.3 per cent of their body weight, clearly more than on tirzepatide alone. The price: more treatment discontinuations. Phase 3 is due to start in 2026.
Key points
- The combination of eloralintide 9 mg and tirzepatide 15 mg reduced body weight by 23.3 % after 48 weeks, tirzepatide 15 mg alone by 14.8 %.
- EloraTZP targets three hormone pathways: GIP, GLP-1 and amylin – an approach Lilly describes as “more physiological”.
- Discontinuations due to adverse events ranged from 10.8 to 27 % in the combination arms, compared with 2.9 % on tirzepatide alone.
- Phase 3 is to begin by the end of 2026 with a co-formulation in a single injection and an optimised titration schedule.
On 30 September 2026, at the 62nd Annual Meeting of the European Association for the Study of Diabetes (EASD) in Milan, Eli Lilly presented Phase 2b data on EloraTZP. Behind the name is a combination of the well-known tirzepatide and eloralintide, a selective amylin receptor agonist. The message of the press release: more weight loss and better blood glucose than with tirzepatide alone.
Three hormones instead of two
Tirzepatide activates the receptors for GIP and GLP-1. Eloralintide adds amylin, another hormone the body releases after eating. According to Lilly, the agonist has minimal activity at the calcitonin receptor. The combination thus addresses three nutrient-stimulated hormone pathways that regulate hunger and glucose metabolism via different receptors. Lilly’s other great hope, retatrutide, also targets three receptors, but relies on glucagon rather than amylin as the third.
Kenneth Custer, President of Lilly Cardiometabolic Health, calls EloraTZP the company’s “next frontier” and speaks of a potentially “additive and more physiological” approach.
The numbers from the study
The double-blind, placebo-controlled study (NCT06603571) ran for 48 weeks in the USA and Argentina. It enrolled 367 adults with obesity or overweight and type 2 diabetes, weighing 105.4 kg on average, with an HbA1c of 8.1 %. They were randomised to ten arms.
| Arm | Weight | HbA1c |
|---|---|---|
| Eloralintide 9 mg + tirzepatide 15 mg | −23.3 % (−24.6 kg) | −2.9 % |
| Eloralintide 6 mg + tirzepatide 10 mg | −19.9 % | −2.6 % |
| Eloralintide 6 mg + tirzepatide 5 mg | −19.4 % | −2.7 % |
| Tirzepatide 15 mg alone | −14.8 % (−15.6 kg) | −2.4 % |
| Eloralintide 6 mg alone | −12.3 % | −1.4 % |
| Placebo | −3.0 % | −0.3 % |
The middle arm stands out: even tirzepatide 5 mg plus eloralintide 6 mg, at 19.4 %, clearly outperformed the highest dose of tirzepatide.
Lead investigator Liana K. Billings (Endeavor Health, Illinois) stresses that participants lost “substantial” weight across all dose combinations while also meaningfully lowering their HbA1c.
The catch: tolerability
The most common adverse events were gastrointestinal, mostly mild to moderate and mainly during dose escalation. They occurred more often in the combination arms than on monotherapy.
This shows in discontinuations due to adverse events: 10.8 to 27.0 % in the EloraTZP arms, 2.9 % on tirzepatide 15 mg. The placebo arm was also strikingly high at 16.7 %. In the study, both substances were escalated in parallel every four weeks – a schedule Lilly intends to revise for Phase 3.
What happens next
Lilly plans to start the Phase 3 trials by the fourth quarter of 2026. They will use a co-formulation combining both substances in a single injection, with an optimised titration schedule. Eloralintide as monotherapy is already in separate Phase 3 trials for the treatment of obesity.
What this means for the pharmacy
Nothing concrete for now: EloraTZP is an investigational product, and approval is years away. Questions at the counter are likely to come anyway, because “23 per cent” is a number that sticks. Anyone putting it into context should mention two things: the data come from a Phase 2 study in people with type 2 diabetes, and the additional weight loss came at the price of markedly more treatment discontinuations. Whether the better titration schedule changes that, only Phase 3 will tell.
References
- 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, 30 September 2026, prnewswire.com
