Abstract
This analysis assessed whether responses with exenatide once weekly plus dapagliflozin (n = 231), exenatide once weekly alone (n = 230), or dapagliflozin alone (n = 233) differed in key patient subpopulations of the DURATION-8 trial. Potential treatment-by-subgroup interactions for changes in glycated haemoglobin (HbA1c) and body weight after 28 weeks were evaluated among subgroups determined by baseline HbA1c, age, sex, body mass index, type 2 diabetes duration, race, ethnicity and estimated glomerular filtration rate (eGFR). Exenatide once weekly plus dapagliflozin reduced HbA1c and body weight across all subgroups: least-squares mean reductions ranged from -8.4 to -26.1 mmol/mol (-0.77% to -2.39%) for HbA1c and from -2.07 to -4.55 kg for body weight. Potential treatment-by-subgroup interactions (P < .10) were found for HbA1c change by age (P = .016) and eGFR (P = .097). Age subgroup analysis findings were not consistent with expected mechanistic effects, with the small number of patients aged ≥65 years (n = 74 vs n = 499 for patients aged <65 years) limiting the interpretability of the interaction term. In the exenatide once weekly plus dapagliflozin and dapagliflozin groups, but not the exenatide once weekly group, HbA1c reductions were greater among patients with eGFR ≥90 vs ≥60 to <90 mL/min/1.73 m(2) (least-squares mean reductions of -23.6 vs -19.0 mmol/mol [-2.16% vs -1.74%], -17.3 vs -12.0 mmol/mol [-1.58% vs -1.10%], and -17.7 vs -16.9 mmol/mol [-1.62% vs -1.55%] for the respective treatments); this was consistent with the mechanism of action of dapagliflozin. A potential treatment-by-subgroup interaction was observed for change in body weight by sex (P = .099), with greater weight loss for women vs men across all treatments (range -2.56 to -3.98 kg vs -0.56 to -2.99 kg). In conclusion, treatment with exenatide once weekly plus dapagliflozin reduced HbA1c and body weight across all patient subgroups and was more effective than exenatide once weekly or dapagliflozin alone in all adequately sized subgroups.