Efficacy and Safety of High-Dose Mizoribine Combined With Cyclosporine, Basiliximab, and Corticosteroids in Renal Transplantation: A Japanese Multicenter Study

Abstract Mizoribine (MZR) is an immunosuppressive agent that exhibits a less potent immunosuppressive effect at doses up to 3 mg/kg/d. We investigated whether high-dose MZR is effective and safe for renal transplant patients in conjunction with cyclosporine (CsA), basiliximab, and corticosteroids. Ninety Japanese renal transplant patients were administered MZR (6 mg/kg/d), CsA (7 mg/kg/d), prednisolone (maintenance dose, 10 mg/d), and basiliximab (20 mg/body). They were compared with a control group of 81 renal transplant patients who received mycophenolate mofetil (MMF; 1500 mg/d), CsA, prednisolone, and basiliximab. The 2-year patient and graft survival rates were 98.9% and 97.8% in the MZR group and 98.8% and 97.5% in the MMF group, respectively. The rejection rate within 2 years after transplantation was 21.1% in the MZR group and 16.0% in the MMF group; the difference was nonsignificant. None of the MZR group developed cytomegalovirus (CMV) disease, whereas 12.3% of the MMF group contracted CMV ( P < .0001). CMV viremia developed in 28.9% of the MZR group vs 46.9% of the MMF group ( P < .0001); their peak antigen levels were 20.4 ± 44.1 and 252.8 ± 527.0 ( P < .01). Furthermore, the incidence of gastrointestinal disorder, hyperlipidemia, and blood disorder was significantly lower in the MZR group than in the MMF group. The combination of high-dose MZR with CsA, basiliximab, and corticosteroids not only provides satisfactory immunosuppression but is also associated with a low incidence of CMV infection and gastrointestinal and blood disorders.