Mycophenolate mofetil substitution for cyclosporine A in renal transplant recipients with chronic progressive allograft dysfunction: the "creeping creatinine" study

Background. This study determined whether cyclosporine A (CsA)-treated renal allograft recipients with deteriorating renal function ("creeping creatinine") secondary to chronic allograft nephropathy (CAN) benefit from the addition of mycophenolate mofetil (MMF) to their immunosuppressive regimen, followed by withdrawal of CsA. Methods. In a controlled, open, multicenter study, CsA-treated renal allograft recipients with progressively deteriorating renal function were randomized to have their CsA discontinued with the concomitant addition of MMF to their regimen (group A) or to continue treatment with CsA (group B). The primary endpoint was the response rate over the 6-month period after withdrawal of CsA in group A or the equivalent time in group B. Response was defined as a stabilization or reduction of serum creatinine (SCr), as evidenced by a flattening or positive slope of the 1/SCr plot and no graft loss. Secondary endpoints included the incidence of acute rejection, graft and patient survival, and changes in selected metabolic parameters. Results. The response rate in the primary intent-to-treat population (n = 122) was 58% (36/62) in group A versus 32% (19/60) in group B (P= 0.0060). The corresponding percentages of responders in the per-protocol population (n = 107) were 60% (36/60) and 26% (12/47), respectively (P=0.0008). There were no acute rejections in group A during the study period. Patients in this group also experienced a significant decrease in total cholesterol. Conclusions. In patients with progressively deteriorating renal function secondary to CAN, addition of MMF followed by withdrawal of CsA results in a significant improvement in transplant function without the risk of acute rejection.