Safety and Efficacy of Exenatide Once Weekly Plus Dapagliflozin Once Daily Versus Exenatide or Dapagliflozin Alone in Patients With Type 2 Diabetes Inadequately Controlled With Metformin Monotherapy: 52-Week Results of the DURATION-8 Randomized Controlled Trial

OBJECTIVE Among patients with type 2 diabetes uncontrolled with metformin, exenatide once weekly (QW) plus dapagliflozin combination produced greater reductions in glycemia, weight, and systolic blood pressure (SBP) at 28 weeks than exenatide QW or dapagliflozin alone (DURATION-8). Here, we investigated the safety and maintenance of efficacy at 52 weeks, after a 24-week extension. RESEARCH DESIGN AND METHODS This phase 3, multicenter, double-blind study randomized adults with type 2 diabetes (with glycated hemoglobin [HbA1c] 8.0–12.0% [64–108 mmol/mol] and on metformin ≥1,500 mg/day) to exenatide QW (2-mg subcutaneous injection) plus once-daily dapagliflozin (10-mg oral tablet), exenatide QW plus oral placebo, or dapagliflozin plus injected placebo. Extension-period P values were nominal. RESULTS Of 1,375 patients screened, 695 were randomized (mean baseline HbA1c 9.3% [78 mmol/mol]); 81.2% completed the study, and 75.3% completed treatment. At 52 weeks, HbA1c reductions were greater with exenatide QW plus dapagliflozin (least squares mean change −1.75% [−19.1 mmol/mol]) versus exenatide QW (−1.38% [−15.1 mmol/mol]; P = 0.006) or dapagliflozin (−1.23% [−13.4 mmol/mol]; P < 0.001); mean HbA1c values were 6.9% (52 mmol/mol), 7.2% (55 mmol/mol), and 7.4% (57 mmol/mol), respectively. Weight and SBP reductions were greater with exenatide QW plus dapagliflozin (−3.31 kg and −4.5 mmHg) versus exenatide QW (−1.51 kg and −0.7 mmHg; both P < 0.001) but similar to those with dapagliflozin (−2.28 kg and −2.7 mmHg; P = 0.057 and P = 0.100, respectively). The exenatide QW plus dapagliflozin regimen was well tolerated with no unexpected safety findings; more patients treated with exenatide QW experienced gastrointestinal and injection site–related adverse events. No major hypoglycemia occurred. CONCLUSIONS Among patients with type 2 diabetes uncontrolled with metformin, exenatide QW plus dapagliflozin provided sustained improvements in glycemia, weight, and SBP over 52 weeks, with no unexpected safety findings.