We conducted a randomized, double-blind, placebo-controlled, phase II trial to assess safety and efficacy of the DPP-4 inhibitor vildagliptin. Intraindividual differences in oral glucose tolerance test (OGTT)-derived 2-h plasma glucose (2HPG) from baseline to 3 months after treatment served as primary endpoint. Among secondary out- comes, we evaluated HbA1c, metabolic and safety parameters, as well as OGTTs at 1 month after drug discontinuation. Of 509 stable KTRs who were screened in our outpatient clinic,