Alloway, R.; Vanhaecke, J.; Yonan, N.; White, M. ; Haddad, H.; Rabago Juan Aracil, Gregorio
; Tymchak, W. ; Díaz Molina, B.; Grimm, M. ; Eiskjaer, H. ; Karpf, C.; Undre, N.
BACKGROUND: A prolonged-release formulation of tacrolimus for once-daily administration (tacrolimus QD) has been developed. This phase II, open-label, multicenter, prospective single-arm study compared the pharmacokinetics (PK) of tacrolimus in stable heart transplant patients before and after conversion from twice-daily tacrolimus (tacrolimus BID) to tacrolimus QD. METHODS: Heart transplant recipients (>= 6 months after transplant), previously maintained on tacrolimus BID based therapy, received tacrolimus BID from Days 1 to 7 and were converted on a I: I (mg/mg) basis to tacrolimus QD. Five 24-hour PK profiles were collected (Days 1, 7, 8, 14, 21). Safety parameters were also evaluated. RESULTS: Of 85 patients, 45 (50.6%) completed all 5 evaluable PK profiles. Steady-state tacrolimus area under the curve, 0 to 24 hours (AUC(0-24)) and minimum concentration (C-min) were comparable for both formulations, with treatment ratio means of 90.5% (90% confidence intervals [CI], 86.4%-94.6%) and 87.4% (95% CI, 82.9%-92.0%), respectively (acceptance interval, 80%-125%). There was good correlation between AUC(0-24) and C-min for tacrolimus QD (r = 0.94) and BID (r = 0.91). The relationship between these 2 parameters was also similar. CONCLUSIONS: This study provides evidence for successful conversion from tacrolimus BID to QD on a 1:1 (mg/mg) total doily dose basis. Approximately one-third of patients may require dose adjustments. Both formulations were well tolerated, with stable renal function during the study. Adverse events were reported by approximately one-tenth of patients receiving tacrolimus BID and a quarter of those who received QD. J Heart Lung Transplant 2011;30:1003-10 (C) 2011 International Society for Heart and Lung Transplantation. All rights reserved.