In a multicenter , randomized , double-blind , placebo-controlled , parallel-group study , imeglimin ( 1,500 mg b.i.d. ) or placebo was added to sitagliptin ( 100 mg q.d. ) over 12 weeks in 170 patients with type 2 diabetes ( mean age 56.8 years ; BMI 32.2 kg/m ( 2 ) ) that was inadequately controlled with sitagliptin alone ( A1C 7.5 % ) during a 12-week run-in period .