Renal function, efficacy, and safety of sirolimus and mycophenolate mofetil after short-term calcineurin inhibitor-based quadruple therapy in de novo renal transplant patients: one-year analysis of a randomized multicenter trial.

Background: De novo sirolimus in calcineurin inhibitor-free regimens, although potentially useful to improve early renal function, are complicated by various drug-related side effects.

Methods: We report a prospective open-label, multicenter, randomized trial to evaluate early conversion from a CsA-based to a sirolimus (SRL)-based regimen 10 to 24 days after renal transplantation. Of the 196 patients, 141 patients with a low-to-moderate immunological risk were eligible to be converted to SRL or to continue CsA. All patients received antithymocyte globulin-F single-bolus induction, mycophenolate mofetil, and steroids.

Results: The primary endpoint, renal function determined by S-creatinine and estimated glomerular filtration rate calculated by Nankivell formula at 12 months was significantly better in the SRL group (1.51+/-0.59 vs. 1.87+/-0.98 mg/dL or 64.5+/-25.2 vs. 53.4+/-18.0 mL/min/1.73 m). Patient survival, graft survival, and incidence of biopsy-proven acute rejection after conversion were not statistically different. Drug discontinuations were significantly higher in the SRL group (36.2% vs. 19.7%). Significantly, more patients in the SRL group reported acne, aphtous, and temporary hyperlipidemia, whereas cytomegalovirus viremia was significantly decreased (7.3% vs. 28.2%).

Conclusions: Early conversion to a calcineurin inhibitor-free regimen with SRL in combination with mycophenolate mofetil may be a useful strategy to improve renal function. The identification of appropriate candidates and safe management of SRL-related adverse events will be a key to avoid the high rate of dropouts, which currently limit the broad applicability of this protocol.