A 39-month follow-up study to evaluate the safety and efficacy in kidney transplant recipients treated with modified-release tacrolimus (FK506E)-based immunosuppression regimen

Background: We initially performed a study to evaluate the safety and efficacy of modified-release tacrolimus (FK506E) in a phase 3, 2-arm, 6-month, randomized, open-label, multicenter trial in Korean living donor de novo kidney transplant recipients. We then performed an extended study to evaluate the long-term safety and efficacy of a FK506E-based regimen up to 45 months posttransplantation in recipients already treated with FK506E. Methods: Initial study was designed as a randomized, open-label, comparative, multicenter study in de novo living donor kidney transplant recipients. The patients were randomized to an FK506E versus a control (FK506) group (1:1). Recipients who completed a 6-month FK506E treatment study were enrolled in the 39-month follow-up study. Primary end-points were patient and graft survivals at posttransplantation 45 months. Secondary end-point was the incidence of a clinical or biopsy-proven acute rejection episode between 6 and 45 months posttransplantation. Results: In the initial 6-month de novo study 124 enrolled patients were randomized into either the FK506E (n = 62) or the control group (n = 62). The incidence of an acute rejection episode was 19.4% (n = 12) in the FK506E versus 16.1% (n = 10) in the control group (P =.638). There was no mortality or graft failure among the 44 recipients enrolled in this additional 39-month follow-up study. There was 1 patient with biopsy-proven acute cellular rejection episode (2.3%) who underwent steroid pulse therapy with renal function recovery. At the time of study completion 40/44 recipients (90.9%) maintained FK506E treatment. Conclusion: This 39-month study following the initial 6-month FK506E study period showed an FK506E-based immunosuppressive regimen in living donor kidney transplantation recipients to be safe and effective.