Search

There are limited clinical data regarding prolonged-release tacrolimus (PR-T) use in pediatric transplant recipients. This Phase 2 study assessed the efficacy and safety of PR-T in stable pediatric kidney, liver, and heart transplant recipients (aged ≥5 to ≤16 years) over 1 year following conversion from immediate-release tacrolimus (IR-T), on a 1:1 mg total-daily-dose basis. Endpoints included the incidence of acute rejection (AR), a composite endpoint of efficacy failure (death, graft loss, biopsy-confirmed AR, and unknown outcome), and safety. Tacrolimus dose and whole-blood trough levels (target 3.5-15 ng/ml) were also evaluated. Overall, 79 patients (kidney, n = 48; liver, n = 29; heart, n = 2) were assessed. Following conversion, tacrolimus dose and trough levels remained stable; however, 7.6-17.7% of patients across follow-up visits had trough levels below the target range. Two (2.5%) patients had AR, and 3 (3.8%) had efficacy failure. No graft loss or deaths were reported. No new safety signals were identified. Drug-related treatment-emergent adverse events occurred in 28 patients (35.4%); most were mild, and all resolved. This study suggests that IR-T to PR-T conversion is effective and well tolerated over 1 year in pediatric transplant recipients and highlights the importance of therapeutic drug monitoring to maintain target tacrolimus trough levels., (© 2019 Astellas Pharma Europe. Transplant International published by John Wiley & Sons Ltd on behalf of Steunstichting ESOT.)

BACKGROUND The DIAMOND study of de novo liver transplant patients showed that prolonged-release tacrolimus exposure in the acute post-transplant period maintained renal function over 24 weeks of treatment. To assess these findings further, we performed a post-hoc analysis in patients according to baseline kidney function, Model for End-stage Liver Disease [MELD] scores, and donor age. MATERIAL AND METHODS Patients received prolonged-release tacrolimus (initial-dose, Arm 1: 0.2 mg/kg/day, Arm 2: 0.15-0.175 mg/kg/day, Arm 3: 0.2 mg/kg/day delayed until Day 5), mycophenolate mofetil and 1 steroid bolus. Arms 2 and 3 also received basiliximab. The recommended tacrolimus target trough levels to Day 42 post-transplantation were 5-15 ng/mL in all arms. In this post-hoc analysis, change in renal outcome, based on estimated glomerular filtration rate (eGFR), Modified Diet in Renal Disease-4 (MDRD4), values from baseline to Week 24 -post-transplantation, were assessed according to baseline patient factors: eGFR (≥60 and ˂60 mL/min/1.73 m²), MELD score (˂25 and ≥25) and donor age (˂50 and ≥50 years). RESULTS Baseline characteristics were comparable (Arms 1-3: n=283, n=287, n=274, respectively). Patients with baseline renal function, eGFR ≥60 mL/min/1.73 m², experienced a decrease in eGFR in all tacrolimus treatment arms. In patients with lower baseline renal function (eGFR ˂60 mL/min/1.73 m²), an advantage for renal function was observed with both the early lower-dose and delayed higher-dose tacrolimus regimens compared with the early introduction of higher-dose tacrolimus. At Week 24, renal function was higher in the early-lower tacrolimus arm with older donors, and the delayed higher-dose tacrolimus arm with younger donors, both compared with early higher-dose tacrolimus. CONCLUSIONS Pre-transplantation factors, such as renal function and donor age, could guide the choice of prolonged-release tacrolimus regimen following liver transplantation.

This study was a Phase II, open-label, multicenter, single-arm, cross-over study comparing the pharmacokinetics (PK) of tacrolimus in stable pediatric kidney, liver, or heart allograft recipients converted from immediate-release tacrolimus (IR-T) to prolonged-release tacrolimus (PR-T). In Days -30 to -1 of screening period, patients received their IR-T-based regimen; during Days 1-7, patients received study IR-T (same dose as screening). On Day 7, the first 24-hours PK profile was taken; patients were then converted to PR-T (1 mg:1 mg), with a second 24-hours PK profile taken on Day 14. The primary end-point was tacrolimus area under the blood concentration-time curve over 24 hours (AUC 24 ); secondary end-points were maximum concentration C max and concentration at 24 hours C 24 . The predefined similarity interval for confidence intervals (CIs) of least squares mean (LSM) ratios was 80%-125%. The PK analysis set comprised 74 pediatric transplant recipients (kidney, n = 45; liver, n = 28; heart, n = 1). PR-T:IR-T LSM ratio (90% CI) was similar overall for AUC 24 , max , and C 24 , and for kidney and liver recipients for AUC 24 (LSM ratio, kidney 91.8%; liver 104.1%) and C 24 (kidney 90.5%; liver 89.9%). Linear relationship was similar between AUC 24 and C 24 , and between PR-T and IR-T (rho 0.89 and 0.84, respectively), suggesting that stable pediatric transplant recipients can be converted from IR-T to PR-T at the same total daily dose, using the same therapeutic drug monitoring method., (© 2019 The Authors. Pediatric Transplantation published by Wiley Periodicals, Inc.)

Tacrolimus granules were developed for patients who are unable to swallow capsules. Therapeutic drug monitoring (TDM) is required to optimize efficacy and safety, which is based on C trough for tacrolimus capsules. Pharmacokinetic (PK) data for tacrolimus granules are required to establish the basis for TDM in those who are unable to swallow capsules. In this phase IV study (NCT01371331) of children undergoing liver, kidney, or heart transplantation, patients received tacrolimus granules 0.15 mg/kg twice daily; first dose was administered within 24 hours of reperfusion. PK analysis samples were collected after reperfusion, after first dose of tacrolimus (Day 1), and at steady state (Day 7; >4 days stable dose). Of the 52 transplant recipients enrolled, 38 had two evaluable PK profiles. Mean AUC tau after first dose of tacrolimus was 211, 97, and 224 hour*ng/mL in liver, kidney, and heart transplant recipients, respectively; corresponding mean AUC tau at steady state was 195, 208, and 165 hour*ng/mL. C trough and AUC tau were positively correlated after first dose of tacrolimus and at steady state (Pearson's coefficients: r = 0.81 and r = 0.87, respectively). This study demonstrated that C trough is a reliable marker for TDM in pediatric transplant recipients treated with tacrolimus granules, consistent with TDM for other tacrolimus formulations., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Phase 2, parallel-group, multicenter, open-label, 4-week study, comparing PK of PR-T vs IR-T in de novo pediatric patients undergoing primary kidney, liver, or heart transplantation. Patients randomized 1:1 to receive once daily, PR-T-, or twice-daily, IR-T-based regimens; dose adjustments permitted after Day 1. Twenty-four-hour PK profiles collected on Days 1, 7, and 28. Primary endpoint: tacrolimus AUC 24 . Secondary end points included tacrolimus C 24 and C max . Endpoints compared between PR-T and IR-T on Days 1, 7, and 28. Predefined similarity interval for CIs of LSM ratios: 80%-125%. PK analysis set comprised 33 patients (PR-T, n = 15; IR-T, n = 18). Overall, AUC 24 and C max were lower on Day 1 vs 7 and 28. Geometric LSM ratios of PR-T:IR-T on Days 1, 7, and 28 were 66.3%, 92.5%, 99.9%, respectively, for AUC 24 ; 66.3%, 82.2%, 90.9% for C 24 ; and 77.3%, 120.3%, 92.2% for C max . AUC 24 90% CI within predefined similarity interval on Day 28; other 90% CIs fell outside. Linear relationship was similar between AUC 24 and C 24 , and between tacrolimus formulations, suggesting that the same therapeutic drug monitoring method can be used with both formulations in de novo pediatric allograft recipients., (© 2018 The Authors. Pediatric Transplantation published by Wiley Periodicals, Inc.)

Background: With the same dose of tacrolimus, lower systemic exposure on the first day of dosing has been reported for prolonged-release tacrolimus compared with immediate-release tacrolimus, prompting investigation of differing initial doses., Methods: This substudy of a double-blind, randomized, phase III trial in de novo liver transplant recipients compared the pharmacokinetics of once-daily prolonged-release tacrolimus (initial dose: 0.2 mg/kg/day) versus twice-daily immediate-release tacrolimus (initial dose: 0.1 mg/kg/day) during the first 2 weeks post-transplant., Results: Pharmacokinetic data were analyzed from patients receiving prolonged-release tacrolimus (n=13) and immediate-release tacrolimus (n=12). Mean systemic exposure (AUC 0-24 ) was higher with prolonged-release versus immediate-release tacrolimus. Dose-normalized AUC 0-24 (normalized to 0.1 mg/kg/day) showed generally lower exposure with prolonged-release tacrolimus versus immediate-release tacrolimus. There was good correlation between AUC 0-24 and concentration at 24 hours after the morning dose (r=.96 and r=.86, respectively), and the slope of the line of best fit was similar for both formulations., Conclusions: Doubling the initial starting dose of prolonged-release tacrolimus compared with immediate-release tacrolimus overcompensated for lower exposure on Day 1. A 50% higher starting dose of prolonged-release tacrolimus than immediate-release tacrolimus may be required for similar systemic exposure. However, doses of both formulations can be optimized using the same trough-level monitoring system. (ClinicalTrials.gov number: NCT00189826)., (© 2017 The Authors. Clinical Transplantation Published by John Wiley & Sons Ltd.)

Tacrolimus, a cornerstone immunosuppressant, is available as a twice-daily formulation (tacrolimus bid). A once-daily prolonged-release formulation (tacrolimus qd) has been developed. This 6-week, randomized, phase 2, multicenter, open-label, prospective trial in primary liver transplant recipients investigated and compared the pharmacokinetics (PK) of tacrolimus for qd and bid formulations. All patients received tacrolimus-based immunosuppression (tacrolimus qd, n = 67; bid, n = 62). PK data were available for 77 patients (tacrolimus qd, n = 45; bid, n = 32). Tacrolimus area under the curve (AUC) from 0 to 24 hours (AUC(0-24) ) at equivalent doses was approximately 50% lower for tacrolimus qd than for bid on day 1 (146 versus 264 ng · h/mL, respectively), but by day 14 was comparable between treatments (324 and 287 ng · h/mL, respectively) with higher tacrolimus qd doses. There was a strong correlation between AUC(0-24) and concentration at 24 hours for tacrolimus qd and bid (r = 0.92 and r = 0.76, respectively). Furthermore, the relationship between these 2 parameters (ie, the slope of the line) was also similar for the 2 formulations. Efficacy endpoints were comparable for both formulations at 6 weeks with no marked differences in incidence, nature, or severity of adverse events between treatments (although the study was not powered to draw efficacy conclusions). These results suggest that targeting the same trough levels will achieve similar total AUC over 24 hours for both tacrolimus qd and tacrolimus bid in de novo liver transplant recipients., (Copyright © 2011 American Association for the Study of Liver Diseases.)

Tacrolimus granules were developed for patients who are unable to swallow capsules. Therapeutic drug monitoring (TDM) is required to optimize efficacy and safety, which is based on Ctrough for tacrolimus capsules. Pharmacokinetic (PK) data for tacrolimus granules are required to establish the basis for TDM in those who are unable to swallow capsules. In this phase IV study (NCT01371331) of children undergoing liver, kidney, or heart transplantation, patients received tacrolimus granules 0.15 mg/kg twice daily; first dose was administered within 24 hours of reperfusion. PK analysis samples were collected after reperfusion, after first dose of tacrolimus (Day 1), and at steady state (Day 7; >4 days stable dose). Of the 52 transplant recipients enrolled, 38 had two evaluable PK profiles. Mean AUCtau after first dose of tacrolimus was 211, 97, and 224 hour*ng/mL in liver, kidney, and heart transplant recipients, respectively; corresponding mean AUCtau at steady state was 195, 208, and 165 hour*ng/mL. Ctrough and AUCtau were positively correlated after first dose of tacrolimus and at steady state (Pearson's coefficients: r = 0.81 and r = 0.87, respectively). This study demonstrated that Ctrough is a reliable marker for TDM in pediatric transplant recipients treated with tacrolimus granules, consistent with TDM for other tacrolimus formulations. [ABSTRACT FROM AUTHOR]

Prolonged-release tacrolimus was developed as a once-daily formulation with ethylcellulose as the excipient, resulting in slower release and reduction in peak concentration ( Cmax) for a given dose compared with immediate-release tacrolimus, which is administered twice daily. This manuscript reviews pharmacokinetic information on prolonged-release tacrolimus in healthy subjects, in transplant recipients converted from immediate-release tacrolimus, and in de novo kidney and liver transplant recipients. As with the immediate-release formulation, prolonged-release tacrolimus shows a strong correlation between trough concentration ( Cmin) and area under the 24-hour time-concentration curve ( AUC24), indicating that trough whole blood concentrations provide an accurate measure of drug exposure. We present the pharmacokinetic similarities and differences between the two formulations, so that prescribing physicians will have a better understanding of therapeutic drug monitoring in patients receiving prolonged-release tacrolimus. [ABSTRACT FROM AUTHOR]