Sirolimus experience at a Swedish transplantation center

Sirolimus is an interesting drug due to its original mechanism of action and because it seems to lack the nephrotoxicity associated with calcineurin inhibitors. During the past 10 years, sirolimus has undergone several clinical trials. Beginning with phase I studies, our first patient given sirolimus was enrolled in 1993, after which we participated in sirolimus phase II trials and finally conducted the large phase III study that led to registration of sirolimus in the European Union (EU) in 2001. Altogether, 111 patients have been treated with sirolimus in our department. Initially, we participated in clinical trials evaluating sirolimus in combination with cyclosporine, but later we focused on studies using sirolimus as base therapy. We found sirolimus to be an effective immunosuppressant lacking several of the disturbing side effects associated with calcineurin inhibitors. It has a high antirejection efficacy and yields excellent survival results, with better renal function than that achieved by calcineurin inhibitors. The main side effects, hyperlipidemia and leukothrombocytopenia, are usually easily manageable. Sirolimus presents an alternative to prophylactic immunosuppression with calcineurin inhibitors and, in the field of transplantation, it represents a welcome addition to the immunosuppressive armamentarium.