Glucagon-like peptide 1 receptor agonist or bolus insulin with optimized basal insulin in type 2 diabetes

Mealtime insulin is commonly added to manage hyperglycemia in type 2 diabetes when basal insulin is insufficient. However, this complex regimen is associated with weight gain and hypoglycemia. This study compared the efficacy and safety of exenatide twice daily or mealtime insulin lispro in patients inadequately controlled by insulin glargine and metformin despite up-titration.

In this 30-week, open-label, multicenter, randomized, noninferiority trial with 12 weeks prior insulin optimization, 627 patients with insufficient postoptimization glycated hemoglobin A1c (HbA1c) were randomized to exenatide (10-20 µg/day) or thrice-daily mealtime lispro titrated to premeal glucose of 5.6-6.0 mmol/L, both added to insulin glargine (mean 61 units/day at randomization) and metformin (mean 2,000 mg/day).

Randomization HbA1c and fasting glucose (FG) were 8.3% (67 mmol/mol) and 7.1 mmol/L for exenatide and 8.2% (66 mmol/mol) and 7.1 mmol/L for lispro. At 30 weeks postrandomization, mean HbA1c changes were noninferior for exenatide compared with lispro (-1.13 and -1.10%, respectively); treatment differences were -0.04 (95% CI -0.18, 0.11) in per-protocol (n = 510) and -0.03 (95% CI -0.16, 0.11) in intent-to-treat (n = 627) populations. FG was lower with exenatide than lispro (6.5 vs. 7.2 mmol/L; P = 0.002). Weight decreased with exenatide and increased with lispro (-2.5 vs. +2.1 kg; P < 0.001). More patients reported treatment satisfaction and better quality of life with exenatide than lispro, although a larger proportion of patients with exenatide experienced treatment-emergent adverse events. Exenatide resulted in fewer nonnocturnal hypoglycemic episodes but more gastrointestinal adverse events than lispro.

Adding exenatide to titrated glargine with metformin resulted in similar glycemic control as adding lispro and was well tolerated. These findings support exenatide as a noninsulin addition for patients failing basal insulin.