Nauck et al, 2007
A multinational, randomised, parallel-group, non-inferiority study of type 2 diabetes patients with inadequate glycaemic control on metformin at a dose of at least 1500 mg/day. 1172 patients were randomised to sitagliptin 100 mg/day or glipizide 5 mg/day (up titrated to a maximum of 20 mg/day) for 52 weeks. The primary analysis assessed whether sitagliptin was non-inferior to glipizide regarding HbA1c changes from baseline at week 52 using a per-protocol (PP) approach. The PP population consists of patients who completed all 52 weeks of treatment and did not have any reasons for exclusion from this population, including no baseline data, no treatment data at week 52 or major protocol violations. The study continued as a randomised, double-blind, active-controlled study for an additional year. The results over the two year treatment period have been reported and evaluated by Seck et al.
The primary efficacy analysis confirmed that sitagliptin was non-inferior to glipizide (mean dose = 10.3 mg/day) regarding HbA1c changes from baseline at Week 52, when both were added to metformin, using a per-protocol (PP) approach.