An Open-Label, Study to Treat Patients With Renal Allograft and Polyoma BK Viruria

This is a multicenter, randomized trial that will evaluate the effect of a combination of leflunomide and orotic acid for the treatment of Polyoma BK viruria. In this multicenter trial, renal allograft patients with the diagnosis of Polyoma BK viruria as determined by a viral level in the urine of 25 million or more copies/mL, and no detectable viremia, will complete a screening visit (V1) to determine eligibility for the study based on inclusion/exclusion criteria. Patients that meet the entrance criteria for this study will be randomly assigned to one of two treatment groups at Visit (2) and enter a 4 month dosing period.