Orforglipron, an oral non-peptide glucagon-like peptide-1 receptor agonist, improves markers of β-cell function and insulin sensitivity in type 2 diabetes.

These participant-level exploratory analyses evaluated the effects of orforglipron, a once-daily, orally administered non-peptide glucagon-like peptide-1 receptor agonist, versus dulaglutide and placebo, on β-cell function and insulin sensitivity biomarkers. Participants (N = 378) in this 26-week phase 2 study with inadequately controlled type 2 diabetes (T2D) were randomly assigned to orforglipron (3, 12, 24, 36, or 45 mg), dulaglutide (1.5 mg), or placebo. Treatment effects on β-cell function and insulin sensitivity markers were assessed, including homeostatic model assessment indices of β-cell function and insulin resistance (HOMA-B and HOMA-IR, respectively); fasting C-peptide, insulin, serum glucose, and glucagon; adiponectin; insulin-like growth factor binding protein 2; proinsulin; and the proinsulin/insulin ratio. Orforglipron doses of 12 mg and higher were associated with improved β-cell function and insulin sensitivity. HOMA-B increased up to 123% (C-peptide) and 132% (insulin) with orforglipron doses of 12 mg and higher from baseline to week 4 before stabilising. HOMA-B increases were greater with all orforglipron doses than with dulaglutide. Additional β-cell function biomarkers, such as fasting proinsulin and the proinsulin/insulin ratio, also improved with orforglipron doses of 12 mg and higher compared with baseline and to a greater extent than seen with dulaglutide. HOMA-IR values decreased up to 16% (C-peptide) and 23% (insulin) with orforglipron by week 26. Reductions in HOMA-IR (insulin) were significant versus baseline only for the highest dose. IGFBP-2 and adiponectin, corollary biomarkers of insulin sensitivity, were generally improved with orforglipron. Increased HOMA-B and improved metabolic biomarkers suggest that treatment with the orally administered non-peptide GLP-1 receptor agonist orforglipron enhanced pancreatic β-cell function and insulin sensitivity in patients with T2D.