Retatrutide, a GIP, GLP-1 and Glucagon Receptor Agonist, for People with Type 2 Diabetes: A Randomised, Double-Blind, Placebo and Active-Comparator Controlled, Parallel-Group, Phase 2 Trial — VialBase Research

Summary

This phase 2 trial evaluated retatrutide in adults with type 2 diabetes, testing multiple dose levels against placebo and dulaglutide (active comparator). The study demonstrated potent glycemic and weight-loss effects, with retatrutide showing superiority over dulaglutide for both endpoints.

Key Findings

• HbA1c reduction: up to -2.02% (12mg) vs -0.01% (placebo) and -1.41% (dulaglutide 1.5mg) at 36 weeks
• Weight loss: up to -16.94% (12mg) vs -3.00% (placebo) at 36 weeks
• 71% of patients on 12mg achieved HbA1c <5.7% (normoglycemia)
• Dose-dependent efficacy across 0.5-12mg range
• Retatrutide 8mg and 12mg superior to dulaglutide for HbA1c and weight
• Glucagon component may contribute to liver fat reduction

Methodology

Phase 2, double-blind, randomized trial. 281 adults with T2DM (HbA1c 7.0-10.5%) on metformin randomized to retatrutide (0.5, 4, 8, or 12mg), dulaglutide 1.5mg, or placebo weekly for 36 weeks. Primary endpoint: HbA1c change from baseline at 24 weeks.

Limitations

• Phase 2 — not powered for definitive efficacy conclusions
• Dulaglutide 1.5mg is a moderate comparator (not semaglutide or tirzepatide)
• 36-week duration — long-term safety not established
• Liver fat reduction mechanism and magnitude need further study
• Phase 3 trials needed to confirm these results

Relevance to Content

Demonstrates retatrutide’s dual utility for both obesity and T2DM. The glucagon receptor agonism adds unique metabolic effects (liver fat, thermogenesis) beyond what GLP-1 or GIP/GLP-1 agonists offer. Relevant for content positioning retatrutide as the next major advance in metabolic medicine.

See Also

• Parent compound: Retatrutide
• Semaglutide
• Tirzepatide