Randomized, Open-Label, Phase IV, Korean Study of Kidney Transplant Patients Converting From Cyclosporine to Prolonged-Release Tacrolimus Plus Standard- or Reduced-Dose Corticosteroids

Background This 24-week, multicenter, randomized, exploratory, comparative, open-label, phase-IV study assessed the safety and efficacy of prolonged-release tacrolimus (PR-T) with reduced-dose versus standard-dose corticosteroids in stable kidney transplant recipients in Korea after converting from cyclosporine-based therapy. Methods At baseline, patients were converted from cyclosporine-based to PR-T-based immunosuppression and randomized (1:1) to receive either corticosteroids maintained at prestudy dose (standard-dose group) or tapered from week 4 to 50% of the prestudy dose by week 12 (reduced-dose group). Patients were seen at baseline and weeks 1, 4, 12, and 24. The primary endpoint was change in estimated glomerular filtration rate (Modification-of-Diet-in-Renal-Disease-4) between baseline and week 24. Secondary endpoints included either acute rejection or patient-reported satisfaction with PR-T. Adverse events (AEs) were recorded. Results Overall, 150 patients were randomized into a reduced-dose group (n = 73) and a standard-dose group (n = 77). At week 24, mean ± standard deviation for corticosteroid dose was 2.5 ± 0.9 mg and 5.0 ± 1.3 mg, respectively. Mean change in estimated glomerular filtration rate from baseline to week 24 was +1.5 ± 9.1 mL/min/1.73 m2 (P = .1567) and +3.4 ± 10.6 mL/min/1.73 m2 (P = .0065), respectively, and not significantly different between groups. There were no acute rejection episodes. Most respondents (>70%) considered PR-T more convenient than cyclosporine. AE incidence was similar between groups. The most common AEs experienced by ≥3% of patients in either treatment group were gastrointestinal events (20.8% and 28.6% of patients receiving reduced- and standard-dose corticosteroids, respectively). Most AEs in both treatment groups were mild or moderate in severity. Conclusion Renal function was maintained following conversion from cyclosporine to PR-T, irrespective of corticosteroid regimen; PR-T enables reduced corticosteroid dosage.