Efficacy and Safety of Once-Weekly Dulaglutide in Type 2 Diabetes Patients Using Insulin: Exploratory Subgroup Analysis by Insulin Regimen

Purpose In East Asian patients, type 2 diabetes mellitus (T2DM) is characterized primarily by beta-cell dysfunction, with lower insulin secretion than in Caucasian individuals. Therefore, bolus insulin and premixed insulin containing a bolus insulin component are important therapeutic tools in Japan, in addition to basal insulin. This subgroup analysis is stratified by insulin regimen and uses data from a phase 4, randomized, placebo-controlled, double-blind and subsequent open-label study in Japan to assess the efficacy and safety of once-weekly dulaglutide combined with various insulin therapies. Methods This multicenter study enrolled Japanese patients with T2DM and inadequate glycemic control [glycated hemoglobin A1c (HbA1c) >= 7.5% to <= 10.5%] on insulin therapy [basal (B), premixed (PM), or basal bolus (BB)] in combination with or without one or two oral antidiabetic agents. Randomized participants received once-weekly dulaglutide 0.75 mg (n = 120) or placebo (n = 39) during a 16-week double-blind treatment period, and dulaglutide during a 36-week open-label extension. In this subgroup analysis, efficacy measures were changes from baseline in HbA1c, 7-point self-monitored blood glucose profiles, and body weight. Safety measures were incidence of adverse events and hypoglycemia during the first 16 weeks. Results At week 16, least squares mean differences (95% CI) regarding changes from baseline in HbA1c for each insulin regimen versus placebo were: B: - 1.62% (- 1.96, - 1.28), PM: - 1.78% (- 2.25, - 1.30), and BB: - 1.15% (- 1.54, - 0.77); p < 0.001 dulaglutide vs. placebo for each subgroup. No significant differences in body weight changes were observed between dulaglutide and placebo for any insulin regimen. Gastrointestinal symptoms were the most commonly observed adverse events in dulaglutide-treated patients. Hypoglycemia incidence rates were: B: dulaglutide 38.5% vs. placebo 23.5%; PM: dulaglutide 38.5% vs. placebo 44.4%; BB: dulaglutide 50.0% vs. placebo 30.8%. Conclusions Overall, dulaglutide was generally well tolerated and improved glycemic control significantly versus placebo, regardless of insulin regimen.