Once-weekly dulaglutide 1.5 mg restores insulin secretion in response to intravenous glucose infusion.

Abstract

To evaluate the effects of dulaglutide 1.5 mg on first- and second-phase insulin secretion in response to an intravenous (i.v.) glucose bolus challenge, in subjects with type 2 diabetes mellitus (T2DM; primary objective) and in healthy subjects. In this randomized, double-blind, placebo-controlled, 2-period crossover study, subjects received a single subcutaneous injection of dulaglutide 1.5 mg or placebo on day 1 of each period. On day 3, subjects underwent a 6-hour insulin infusion, followed by an i.v. glucose bolus and a glucagon challenge during hyperglycaemia. Areas under the concentration-time curve and maximum concentrations for first- (AUC0-10 and Cmax0-10 ) and second-phase secretion (AUC10-180 and Cmax10-180 ) were calculated for insulin and C-peptide. The glucose disappearance constant (Kg ) and homeostasis model assessment of β-cell function (HOMA-β) were assessed. In 20 subjects with T2DM, dulaglutide increased mean insulin AUC0-10 by 7.92-fold and Cmax0-10 by 5.40-fold vs placebo, and mean AUC10-180 and Cmax10-180 by 2.44- and 3.78- fold, respectively. In 10 healthy subjects, dulaglutide increased the mean insulin AUC0-10 by 3.09-fold and Cmax0-10 by 2.96-fold vs placebo, and mean AUC10-180 and Cmax10-180 by 2.04- and 4.15-fold, respectively. The corresponding C-peptide values also increased. Mean Kg and HOMA-β were higher after dulaglutide compared with placebo. In subjects with T2DM, a single dulaglutide 1.5-mg dose restored the first-phase insulin secretion in response to an i.v. glucose bolus, increased the second-phase insulin response and enhanced β-cell function.