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 g/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 ) .