Aims: To assess 5-year efficacy, renal, and safety outcomes following early conversion from cyclosporine to everolimus vs. a standard cyclosporine-based regimen in living-donor kidney transplant (LDKT) recipients.
Materials and methods: The ZEUS study was a randomized, open-label, 1-year, multicenter study in which 300 de novo kidney transplant recipients continued to receive cyclosporine or converted to everolimus at 4.5 months post-transplant, with annual follow-up visits to 5 years post-transplant.
Results: Of the 80 LDKT patients who were randomized, 75 completed the 1-year core study and 60 attended the 5-year follow-up visit. At year 5, 15/31 (48.4%) everolimus patients and 20/29 (69.0%) cyclosporine patients remained on the study drug. Mean adjusted estimated glomerular filtration rate (GFR) at year 5 in LDKT recipients was 67.2 vs. 60.8 mL/min/1.73m2 for everolimus vs. cyclosporine (mean difference 6.4 mL/min/1.73m2; p = 0.031). For patients who remained on study drug, the mean difference was 13.2 mL/min/1.73m2 (p = 0.003), but no significant difference was seen in patients who switched from study drug (mean -2.6 mL/min/1.73m2, p = 0.701). Patient and graft survival rates were similar with everolimus and cyclosporine. Biopsy-proven acute rejection occurred in 22.0% vs. 7.5% of LDKT patients randomized to everolimus vs. cyclosporine (p = 0.116). Only 1 LDKT patient discontinued everolimus due to adverse events during years 1 - 5.
Conclusions: Early initiation of everolimus with calcineurin-inhibitor (CNI) withdrawal after LDKT improved graft function to 5 years post-transplant compared to standard CNI-based therapy. The renal benefit was concentrated in patients who remained on everolimus. An increase in mild acute rejection was not associated with long-term graft loss.