Cost-effectiveness of sirolimus therapy with early cyclosporin withdrawal vs. long-term cyclosporin therapy in Australia

Abstract

Cyclosporin (CsA) is Australia's most widely used immunosuppressant following renal transplantation. Randomized clinical trials demonstrate that sirolimus use for immunosuppression is associated with significantly lower incidence rates of nephrotoxicity and chronic graft rejection, and lower serum creatinine levels, suggesting long-term benefits if used as a replacement therapy for CsA. The cost-effectiveness of replacing CsA with sirolimus after 2-4 months (as approved by Australian regulatory authorities) was assessed relative to continued CsA plus low-dose sirolimus. A Markov model simulated outcomes over a patient's lifetime from initial transplant. Costs, measured in Australian dollars from the perspective of the Australian healthcare system, included immunosuppressants, dialysis, and inpatient and outpatient treatment. In a cohort with a mean age of 45 yr, the mean lifetime cost per patient is $39,052 greater with the study therapy. However, an average of 272 chronic graft rejections and 91 regrafts are prevented per 1000 patients. The mean predicted survival benefit is 2.086 life-years, or 0.938 quality-adjusted life-years (QALYs) when utility weights and discounting are incorporated. The incremental cost per QALY gained with the study therapy was $41,613. Cost-effectiveness was most sensitive to model duration and dialysis cost. Sirolimus is a cost-effective alternative to CsA for the long-term treatment of patients undergoing renal transplantation.