Lilly drug retatrutide shows strong results in diabetes trial

Thursday 19 March 2026 - 15:45

By: Dakir Madiha

Lilly drug retatrutide shows strong results in diabetes trial

Eli Lilly said its experimental drug retatrutide met all primary and secondary endpoints in a phase 3 clinical trial for type 2 diabetes, delivering significant reductions in blood sugar and body weight over 40 weeks.

The TRANSCEND-T2D-1 trial involved 537 adults whose diabetes was not adequately controlled through diet and exercise alone. Participants received weekly injections of retatrutide at doses of 4 mg, 9 mg, or 12 mg, or a placebo. Patients on the highest dose achieved an average HbA1c reduction of 2.0 percentage points from a baseline of 7.9 percent. Those receiving 12 mg also recorded an average weight loss of 16.6 kilograms, with no plateau observed by week 40.

Retatrutide works by activating three hormone receptors simultaneously, GLP-1, GIP, and glucagon, a mechanism that differentiates it from Lilly’s existing treatments, which target only two. The company said this approach may help address both blood sugar control and obesity, a combination that has historically been difficult to manage in patients with type 2 diabetes.

The safety profile was consistent with other incretin-based therapies. The most common side effects included nausea, diarrhea, and vomiting, mainly during dose escalation. Treatment discontinuation due to adverse events remained limited, reaching 5.1 percent at the highest dose compared with none in the placebo group. A sensory side effect, dysesthesia, was reported in 4.4 percent of patients receiving 12 mg.

The results mark the first phase 3 data from Lilly’s diabetes development program for retatrutide. Additional findings from three more trials in the TRANSCEND-T2D series are expected over the coming year. The drug previously showed strong outcomes in obesity trials, including average weight loss of 28.7 percent over 68 weeks in earlier research.

Lilly plans to release seven additional phase 3 results in 2026 across obesity, sleep apnea, and related conditions. The company is preparing regulatory submissions for obesity treatment by the end of 2026, followed by a filing for diabetes. Shares in Lilly rose in premarket trading after the announcement.