Maintenance Immunosuppression with Intermittent Intravenous

The extensive use of the calcineurininhibitors (CNIs) cyclosporine and tacrolimus as the backbone of mainte-nance immunosuppressive regimens in renal transplant recipients has led to tremendous improvements in graft sur-vival over the past few decades.1 The CNIs have helped reduce the incidence of acute cellular rejection and early graft failure. Despite these remarkable im-provements in short-term graft and pa-tient survival, the long-term results of re-nal transplantation have not improved as dramatically over the same time period. This may be due, in part, to the negative long-term cardiac, metabolic, and renal adverse events associated with current maintenance immunosuppression regi-mens (ie, CNIs, mammalian target of rapamycin [mToR] inhibitors, cortico-steroids).1,2 Drug development in transplantation has focused on new immunosuppressive agents with unique mechanisms of ac-tion and favorable adverse event pro-files.3 An emphasis on tailored therapy has led to the clinical testing of mono-clonal antibodies and fusion proteins di-rected at novel T- and B-lymphocyte tar-gets to provide durable maintenance im-munosuppression in allograft recipients. The use of biologic agents for long-term immunosuppression would represent a paradigm shift from the current doctrin