Subgroup Analysis Stratified by Baseline Pancreatic β-cell Function in a Japanese Study of Dulaglutide in Patients with Type 2 Diabetes

Introduction This analysis investigated the relationship between baseline fasting pancreatic β-cell function and efficacy in Japanese patients with type 2 diabetes (T2D) treated with once-weekly dulaglutide 0.75 mg (dulaglutide) or once-daily liraglutide 0.9 mg (liraglutide) for up to 52 weeks. Methods In a 52-week study of monotherapy in Japanese patients with T2D, patients were categorized into three subgroups defined by tertiles (low, medium, and high) of baseline values of three pancreatic β-cell function parameters [fasting C-peptide, C-peptide index, and secretory units of islets in transplantation (SUIT) index]. Associations between these parameters and efficacy [defined by changes from baseline in glycated hemoglobin (HbA1c), fasting blood glucose (FBG), postprandial blood glucose (PBG), mean of all meals blood glucose excursion, and body weight] in the dulaglutide group (280 patients) or the liraglutide group (137 patients) were evaluated. Results Patients in the subgroups with high insulin-secreting ability (based on pancreatic β-cell function) were younger and had shorter disease duration and higher body mass index compared to those with low insulin-secreting ability. No specific trend was observed between baseline pancreatic β-cell function and changes in HbA1c or FBG. Reductions from baseline in mean PBG and excursion were greatest for patients in the low β-cell function tertiles. Inconsistent trends in body weight were observed across the treatment groups and β-cell function parameters. Conclusion In Japanese patients with T2D, changes in HbA1c and body weight after 52 weeks of treatment with dulaglutide or liraglutide could not be predicted by patients’ fasting pancreatic β-cell function before treatment. Clinical Trial Registration ClinicalTrials.gov (NCT01558271). Funding Eli Lilly K.K. (Kobe, Japan).