Efficacy and safety of vildagliptin in new onset diabetes after kidney transplantation - a randomized, double blind, placebo controlled, trial

New-onset diabetes after transplantation (NODAT) is a serious complication after kidney transplantation, but therapeutic strategies remain underexplored. Dipeptidyl peptidase-4 (DPP-4) inhibitors selectively foster insulin secretion without inducing hypoglycemia, which might be advantageous in kidney transplant recipients (KTRs) with NODAT. 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 outcomes, 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, 63 (12.4%) had 2HPG >=200 mg/dL, 33 of them were randomized and 32 completed the study. In the vildagliptin group 2HPG and HbA1c were profoundly reduced in comparison to placebo (vildagliptin: 2HPG = 182.7 mg/dL, HbA1c = 6.1%; placebo: 2HPG = 231.2 mg/dL, HbA1c = 6.5%; both p <= 0.05), and statistical significance was achieved for the primary endpoint (vildagliptin: 2HPG-difference -73.7 ± 51.3 mg/dL; placebo: -5.7 ± 41.4 mg/dL; p < 0.01). Adverse events were generally mild and occurred at similar rates in both groups. In conclusion, DPP-4 inhibition in KTRs with overt NODAT was safe and efficient, providing a novel treatment alternative for this specific form of diabetes.