Association of clinical events with everolimus exposure in kidney transplant patients receiving reduced cyclosporine

Background: The association between clinical events and everolimus exposure in patients receiving reduced-exposure calcineurin inhibitor therapy is poorly explored. Methods: In a pre-planned, descriptive analysis of data from a randomized controlled trial, events were correlated with everolimus trough concentrations in 556 newly transplanted kidney transplant patients receiving everolimus with reduced-exposure cyclosporine (CsA) and steroids. Influence of everolimus exposure on clinical events was stratified according to predefined time-normalized concentrations. Results: The incidence of treated biopsy-proven acute rejection and graft loss at month 12 was highest in patients with everolimus <3 ng/mL (36.4% and 28.6%, respectively, vs. 9.1-15.3% and 0.9-5.0% with higher concentration ranges). A higher mortality rate was observed in patients with an everolimus trough concentration ≥12 ng/mL (10.0% vs. 1.7-5.6% with lower concentration ranges). The lowest rates of renal dysfunction (defined as poor renal function [estimated GFR, serum creatinine] or proteinuria), wound healing events, peripheral edema, new-onset diabetes mellitus, hypercholesterolemia and hypertriglyceridemia were generally observed with everolimus trough concentration in the range 3-8 ng/mL and CsA <100 ng/mL. Proteinuria occurred most frequently in patients with very low or very high everolimus trough concentrations. Conclusions: These results support an exposure-response relationship between clinical events and everolimus trough concentrations in kidney transplant patients receiving reduced-exposure CsA.