Key takeaways
- An investigational combination of eloralintide and tirzepatide led to an unprecedented 23.3% average weight loss in adults with type 2 diabetes.
What happened
In a Phase IIb clinical trial presented at the European Association for the Study of Diabetes (EASD) annual meeting in Milan, adults with type 2 diabetes and obesity achieved an unprecedented 23.3% average weight loss over 48 weeks using an investigational combination of eloralintide and tirzepatide. Developed by Eli Lilly, this dual-drug regimen paired tirzepatide (the active ingredient in Mounjaro and Zepbound) with eloralintide, an investigational amylin receptor agonist. However, the trial also revealed significant tolerability challenges, with 27% of participants in the highest-dose combination group dropping out of the study due to adverse events.
Why it matters
This clinical development is highly significant for patients with type 2 diabetes, who historically lose less weight on GLP-1 therapies than those without diabetes. The 23.3% weight loss milestone achieved by the combination treatment surpasses the typical results seen with tirzepatide alone even in non-diabetic populations (which averaged 20.9% in previous trials). For the millions of Americans managing both diabetes and obesity, a pharmaceutical intervention that mirrors the weight reduction of metabolic surgery is a major breakthrough.
However, for US consumers looking to buy weight-loss medications online through cash-pay telehealth channels, the high dropout rate presents a major barrier. Cash-paying patients need medications they can tolerate long-term. If more than one in four patients must discontinue the drug due to severe side effects like gastrointestinal distress, the real-world utility of the therapy in a self-pay, virtual care setting may be limited.
What the data says
The double-blind, parallel-group Phase IIb trial randomized 367 adults with obesity or overweight and type 2 diabetes across the US and Argentina into 10 distinct groups. The findings, reported by MedPage Today, highlighted several key data points:
- Weight Loss: Participants taking the highest tested dose of the eloralintide-tirzepatide combination lost an average of 23.3% of their body weight over 48 weeks, compared to 14.8% for those taking tirzepatide alone.
- Extreme Weight Loss: A quarter (25%) of the patients in the highest-dose combination group lost 30% or more of their body weight. Only 12% of those on tirzepatide alone achieved this mark.
- Blood Sugar Control: In the highest-dose combination group, 96% of participants achieved an HbA1c level below 7% (the standard clinical target for diabetes management), and 77% achieved normoglycemia (HbA1c below 5.7%).
- Adverse Events: Approximately 84% of participants in the highest-dose combination group experienced treatment-emergent adverse events, compared to 71.4% in the tirzepatide-only group.
- Discontinuation Rates: Nearly 10 times as many patients in the highest-dose combination arm dropped out of the trial due to side effects compared to the tirzepatide-only arm (27% versus 2.9%).
During the trial, the therapy was administered as two separate weekly injections, though developers plan to formulate the combination into a single injection for future trials. One death was reported in the lowest-dose combination group, but investigators determined it was unrelated to the study drug.
How it compares
Currently, US buyers shopping for weight-loss medications online must choose between single-molecule or dual-molecule therapies. The standard of care, tirzepatide (Zepbound), is a dual GIP/GLP-1 receptor agonist. Eloralintide introduces a third mechanism as a selective amylin receptor agonist. By combining these, the therapy targets three complementary nutrient-stimulated hormones—GIP, GLP-1, and amylin—which are naturally released after eating to regulate satiety and blood sugar.
In terms of efficacy, this combination significantly outperforms existing treatments. While patients with type 2 diabetes typically experience modest weight loss on single-hormone GLP-1s like semaglutide (Ozempic/Wegovy), this triple-hormone approach bridges the gap.
However, the safety profile compares unfavorably to current options. Brand-name tirzepatide has a well-documented and far lower discontinuation rate in clinical trials (typically under 10%). A 27% dropout rate means that while the drug is exceptionally powerful, it may prove too intense for a substantial portion of the cash-paying public who do not have intensive, in-person clinical monitoring to manage severe GLP-1 side effects.
How this fits the bigger picture
This trial represents a growing trend among pharmaceutical developers to combine GLP-1s with amylin agonists to maximize weight loss, even as they grapple with the resulting side effects. We previously explored this delicate balance in our coverage of Lilly's Zepbound-amylin combo weight loss and dropout rates, which similarly demonstrated high efficacy paired with notable tolerability hurdles.
Furthermore, the high discontinuation rate seen in this trial mirrors challenges observed in trials for other next-generation weight-loss drugs. For example, our analysis of the Boehringer survodutide Phase III diabetes data highlighted how a 26% dropout rate could impact real-world compliance for GLP-1 buyers. When patients purchase medications out-of-pocket through online providers or compare pricing on cheapest telehealth GLP-1 platforms, tolerability becomes a primary financial factor. A patient paying $300 to $1,000 per month out-of-pocket is unlikely to continue purchasing a medication that makes them too ill to go about their daily life, regardless of how quickly the pounds come off.
What happens next
Eli Lilly plans to advance the eloralintide-tirzepatide combination into Phase III clinical development by the end of 2026. Additionally, eloralintide is currently being evaluated as a single-agent therapy in separate Phase III trials for obesity.
As clinical trials progress, researchers will focus heavily on optimizing the titration schedule—the speed at which the drug dose is increased—to see if a slower ramp-up can mitigate the severe gastrointestinal side effects and lower the 27% dropout rate. Ultimately, Eli Lilly aims to co-formulate both active ingredients into a single, easy-to-use weekly injection before seeking FDA approval.
CompareRx provides factual information and comparison tools for educational purposes. We do not provide medical advice, diagnosis, or treatment. Always consult with a licensed healthcare provider before starting any weight-loss medication.