Efficacy, Safety, and Patient-Reported Convenience of Converting from Tacrolimus Capsule to Tablet Formulation (Tacrobell®) in Stable Kidney Transplant Recipients: A Single-Center, Non-Comparative, Phase IV Investigator-Initiated Pilot Study

초록

Purpose: Tacrolimus remains a key immunosuppressive agent in kidney transplantation (KT). A newly developed tablet formulation (Tacrobell®) was designed to improve convenience while achieving pharmacokinetics that are nearly equivalent to those of the original capsules. This study evaluated effi cacy, safety, and patientreported satisfaction after switching from tacrolimus capsules to tablets in stable KT recipients. Methods: This single-center, prospective, open-label, investigator-initiated phase IV pilot study enrolled 25 stable KT recipients maintained on capsules ≥3 months. Participants switched to the tablet at a 1:1 dose and were monitored for 48 weeks, with assessments at baseline, Week 2, 24, and 48. Clinical outcomes, laboratory tests, safety endpoints, and patient-reported satisfaction were evaluated. Results: 25 patients were enrolled; two discontinued due to adverse events (headache and gastrointestinal discomfort), and 23 completed the study. Tacrolimus trough concentrations showed transient variation (baseline 6.2 ± 1.33 ng/mL, Week 2 5.26 ± 1.50, Week 24 4.81 ± 1.14, Week 48 5.92 ± 1.80; p = 0.001) but remained within the therapeutic range and returned to baseline by Week 48. In subgroup analysis, trough levels were unchanged after generic-to-generic conversion (Tacrobell® capsule → Tacrobell® tablet; p = 0.174) but signifi cantly decreased after originalto-generic switching (Prograf® capsule → Tacrobell® tablet; p = 0.003). eGFR remained stable (baseline 65.3 ± 19.4 vs Week 48 65.1 ± 23.2 mL/min/1.73 m²; p > 0.05), and graft survival was 100%. One patient developed borderline acute Tcell-mediated rejection, which was successfully treated. Patient satisfaction scores were consistent throughout the study. Conclusions: This exploratory pilot study suggests that switching from tacrolimus capsules to tablets is feasible and well tolerated in stable kidney transplant recipients. Generic-to-generic conversion maintained stable tacrolimus exposure, whereas original-to-generic switching was associated with transient trough reductions. Larger studies integrating pharmacogenetic and formulation-specifi c factors are warranted to optimize individualized tacrolimus therapy. CITATION INFORMATION: Jung C., Oh Y., Kim M. Effi cacy, Safety, and Patient-Reported Convenience of Converting from Tacrolimus Capsule to Tablet Formulation (Tacrobell®) in Stable Kidney Transplant Recipients: A Single-Center, Non-Comparative, Phase IV Investigator-Initiated Pilot Study AJT_ 26/7S1, Volume 26, Issue 7, S1. DISCLOSURES: C. Jung: None.