Eli Lilly's retatrutide shows breakthrough results in Phase 3 diabetes trial

Eli Lilly's experimental drug retatrutide has shown promising results in its first Phase 3 trial. The treatment, designed for Type 2 diabetes patients, met its primary goal by significantly lowering blood sugar levels. Now, the company awaits further data from seven additional late-stage studies expected by the end of this year.

In the completed trial, retatrutide reduced HbA1c levels by 1.7% to 2% over 40 weeks. This compared favourably to the placebo group, which saw only a 0.8% drop. Participants also experienced substantial weight loss, with reductions reaching up to 16.8% at the highest dose.

Unlike many competing drugs, retatrutide works by activating three hormone pathways: GLP-1, GIP, and glucagon. Most similar treatments target just one or two receptors. Despite these results, regulatory approval is still pending as Lilly gathers more evidence.

A long-term study, TRIUMPH-Outcomes, began in April 2024 and will run until 2029. It focuses on adults over 45 with a BMI of at least 27 kg/m² and existing heart or kidney conditions. However, no further Phase 3 trial publications are planned before the end of 2025.

The initial Phase 3 success marks a key step for retatrutide, but full regulatory review will depend on upcoming data. With seven more studies due this year, Lilly aims to strengthen the case for its triple-hormone approach. The drug's potential impact on diabetes and obesity treatment now hinges on these results.