A Phase II, Open-Label, Multi-Center Study to Compare the Pharmacokinetics of Tacrolimus in Stable Pediatric Allograft Recipients Converted From a Prograf® Based Immunosuppressive Regimen to a Tacrolimus Prolonged Release, Advagraf® Based Immunosuppressive Regimen, Including a Long-Term Follow-Up

Parts A \& B: Conversion of stable pediatric allograft recipients from Prograf® immunosuppression to Advagraf® immunosuppression to compare exposure and one year follow-up for safety and efficacy.Part C: Continuation of long-term follow-up and provision of ongoing study medication to subjects to whom Advagraf® is currently not available.