Tacrolimus once daily (ADVAGRAF) versus twice daily (PROGRAF) in de novo renal transplantation: a randomized phase III study

Long-Term Outcome after Early Mammalian Target of Rapamycin Inhibitor-Based Immunosuppression in Kidney Transplant Recipients

Background: The use of mammalian target of rapamycin inhibitors (mTORis) in kidney transplantation increases the risk of donor-specific human leukocyte antigen (HLA) antibody formation and rejection. Here, we investigated the long-term consequences of early mTORi treatment compared to calcineurin inhibitor (CNI) treatment. Methods: In this retrospective single-center analysis, key outcome parameters were compared between patients participating in randomized controlled immunosuppression trials between 1998 and 2011, with complete follow-up until 2018. The outcomes of eligible patients on a CNI-based regimen (n = 384) were compared with those of patients randomized to a CNI-free mTORi-based regimen (n = 81) and 76 patients randomized to a combination of CNI and mTORi treatments. All data were analyzed according to the intention-to-treat (ITT) principle. Results: Deviation from randomized immunosuppression for clinical reasons occurred significantly more often and much earlier in both mTORi-containing regimens than in the CNI treatment. Overall patient survival, graft survival, and death-censored graft survival did not differ between the treatment groups. Donor-specific HLA antibody formation and BPARs were significantly more common in both mTORi regimens than in the CNI-based immunosuppression. Conclusions: The tolerability and efficacy of the mTORi treatment in kidney graft recipients are inferior to those of CNI-based immunosuppression, while the long-term patient and graft survival rates were similar.

The use of extended-release tacrolimus twice a day might be beneficial for selected kidney transplant recipients: a case report

The calcineurin inhibitor tacrolimus, which is available as an immediate- or extended-release formulation, is the standard-of-care immunosuppression after kidney transplantation with low rejection rates, especially in the first year after transplantation. However, its highly variable metabolism rate, narrow therapeutic window, and nephrotoxic side effects require close drug monitoring and individual dosing. Here, we describe first the application of extended-release tacrolimus (ER-Tac) twice daily with beneficial effects in a kidney transplant recipient under extensive therapeutic drug monitoring. A 47-year-old female kidney transplant recipient, who was identified as a fast metabolizer for tacrolimus, presented with declining allograft function and low tacrolimus through levels over time and 8 years after a second kidney transplantation despite the administration of high doses of ER-Tac once daily. Therefore, the area under the concentration-time curve (AUC) showed exceedingly high blood levels of ER-Tac. The latest biopsy of the kidney transplant showed arteriolar hyalinosis with pole vessel stenosis as a sign of chronic transplant vasculopathy and transplant glomerulopathy as a sign of chronic humoral rejection. After the exclusion of other options for immunosuppressive therapy due to the patient's high immunological risk, the patient was switched from ER-Tac once daily to ER-Tac twice daily. After switching to ER-Tac twice daily, the AUC for oral tacrolimus decreased and the transplant function improved despite higher tacrolimus trough levels and a lower total dose administered. This case highlights the importance of careful therapeutic drug monitoring with the performance of an AUC in the follow-up management of kidney transplant recipients.

Sirolimus in combination with low-dose extended-release tacrolimus in kidney transplant recipients

Introduction

Many challenges remain for long-term survival of renal allografts. Once-daily sirolimus (SRL) combined with low-dose extended-release tacrolimus (LER-TAC) may improve medication adherence and reduce the potential nephrotoxicity of calcineurin inhibitors (CNI) compared with standard immunosuppression regimens, thus potentially improving long-term graft survival.

Methods

This retrospective, observational, single-center, propensity score matching (PSM) study compared conversion to SRL combined with low-dose ER-TAC and mycophenolic acid (MPA) combined with standard-dose TAC in kidney transplant recipients. After PSM, there were 56 patients in each group. Efficacy, safety, and medication adherence were evaluated over 12 months.

Results

There was no significant difference between the two groups in terms of graft and recipient survival and incidence of biopsy-proven acute rejection (p = 1.000), and none of the recipients developed dnDSA after conversion. The mean eGFR improved in SRL + LER-TAC group after conversion compared to before conversion (51.12 ± 20.1 ml/min/1.73 m2 vs. 56.97 ± 19.23 ml/min/1.73 m2, p < 0.05). The medication adherence at 12 months after conversion was superior to before conversion (p = 0.002).

Discussion

Our findings suggest that an immunosuppressive regimen of SRL combined with low-dose ER-TAC is no less effective and safe than standard immunosuppressive regimens for renal transplant recipients and may improve graft renal function and medication adherence.

Efficacy and safety of once-daily prolonged-release tacrolimus versus twice-daily tacrolimus in kidney transplant recipients: A meta-analysis and trial sequential analysis

BACKGROUND

Kidney transplantation is the most important treatment for end-stage renal disease. Immunosuppressive therapies can prevent acute rejection for kidney transplant recipients. Tacrolimus is usually administered to prevent graft rejection after transplantation. Previous studies have indicated that once-daily tacrolimus may improve medication adherence. Therefore, this meta-analysis aimed to compare clinical outcomes between once-daily and twice-daily tacrolimus in de novo renal transplant patients.

METHODS

Eligible studies were identified from the Cochrane Library Database, PubMed, and Embase until July 2022. Those randomized controlled trials (RCTs) evaluating once-daily versus twice-daily tacrolimus formulations in de novo renal transplantation were included. A summary risk ratio (RR) and standardized mean difference (SMD) with the 95% confidence interval (CI) were estimated using a random-effects model.

RESULTS

In total, nine RCTs were included. There were no differences in biopsy-confirmed acute rejection rates between patients with once-daily and those with twice-daily tacrolimus (RR, 0.91; 95% CI, 0.73-1.13) in 12 months. Regarding renal function, there was no significant difference between the once-daily and twice-daily tacrolimus groups (SMD, -0.03; 95% CI, -0.12 to 0.07). In addition, the risk of graft failure, death, and adverse events in the first year was similar for the once-daily and twice-daily tacrolimus groups.

CONCLUSION

Our major findings suggest that de novo renal transplantation recipients receiving once-daily tacrolimus immediately after transplantation have comparable efficacy and safety with those recipients who received twice-daily tacrolimus. Therefore, once-daily tacrolimus medication can be an alternative for de novo renal transplantation recipients.

Comparison of the Prolonged- and Immediate-Release Tacrolimus Capsule Formulation: The Patient's View and Medication Satisfaction of Patients After Pediatric Heart Transplantation

BACKGROUND

Medication adherence is essential for long-term success after pediatric organ transplantation. Causes of reduced adherence should be detected early to improve the consequent medication intake. We describe the influence of switching from tacrolimus twice daily (tacrolimus-BID) to tacrolimus once daily (tacrolimus-QD) on medication satisfaction and medication adherence in patients after pediatric heart transplantation.

METHODS

A retrospective analysis was conducted regarding patient satisfaction and adherence to the immunosuppressant tacrolimus after pediatric heart transplantation, before and after conversion from tacrolimus-BID to tacrolimus-QD, using questionnaires.

RESULTS

Thirty-eight patients were enrolled (tacrolimus-BID: n = 35, mean age 15.7 ± 5.2 years; tacrolimus-QD: n = 38, mean age 16.2 ± 5.6 years). The amount of unadministered medication in the last 3 months did not differ between the 2 pharmaceutical forms. However, 17% (n = 6) reported unstable tacrolimus trough levels when taking tacrolimus-BID, vs 8% (n = 3) under tacrolimus-QD (P = .453). However, there was no statistically significant difference in the stability of the last 6 trough levels of each patient (P = .074). A total of 57% (n = 20) of patients had subjective side effects before conversion, compared to only 29% (n = 11) after conversion (P = .013). Regarding the intensity of the side effects, 6 patients reported strong/very strong side effects when taking tacrolimus-BID vs 1 patient when taking tacrolimus-QD (P = .250). In addition, the overall satisfaction with the immunosuppressant was higher under tacrolimus-QD (92% vs 83%; P = .508). However, this improvement was statistically not significant and may not be clinically relevant.

CONCLUSIONS

The amount of forgotten medication was not reduced after conversion from tacrolimus-BID to tacrolimus-QD. However, subjective side effects as well as patient satisfaction improved under tacrolimus-QD.

Long-term Prolonged-release Tacrolimus-based Immunosuppression in De Novo Kidney Transplant Recipients: 5-Y Prospective Follow-up of Patients in the ADVANCE Study

Although prolonged-release tacrolimus (PR-T) is widely approved for posttransplantation immunosuppression in kidney recipients, large-scale studies are required to assess long-term outcomes. We present follow-up data from the Advagraf-based Immunosuppression Regimen Examining New Onset Diabetes Mellitus in Kidney Transplant Recipients (ADVANCE) trial, in which kidney transplant patients (KTPs) received corticosteroid minimization with PR-T.

Methods

ADVANCE was a 24-wk, randomized, open-label, phase-4 study. De novo KTPs received PR-T with basiliximab and mycophenolate mofetil and were randomized to receive an intraoperative corticosteroid bolus plus tapered corticosteroids until day 10 (arm 1) or an intraoperative corticosteroid bolus (arm 2). In this 5-y, noninterventional follow-up, patients received maintenance immunosuppression according to standard practice. The primary endpoint was graft survival (Kaplan-Meier). Secondary endpoints included patient survival, biopsy-confirmed acute rejection-free survival, and estimated glomerular filtration rate (4-variable modification of diet in renal disease).

Results

Follow-up study included 1125 patients. Overall graft survival at 1 and 5 y posttransplantation was 93.8% and 88.1%, respectively, and was similar between treatment arms. At 1 and 5 y, patient survival was 97.8% and 94.4%, respectively. Five-year graft and patient survival rates in KTPs who remained on PR-T were 91.5% and 98.2%, respectively. Cox proportional hazards analysis demonstrated similar risk of graft loss and death between treatment arms. Five-year biopsy-confirmed acute rejection-free survival was 84.1%. Mean ± standard deviation values of estimated glomerular filtration rate were 52.7 ± 19.5 and 51.1 ± 22.4 mL/min/1.73 m² at 1 and 5 y, respectively. Fifty adverse drug reactions were recorded, probably tacrolimus-related in 12 patients (1.5%).

Conclusions

Graft survival and patient survival (overall and for KTPs who remained on PR-T) were numerically high and similar between treatment arms at 5 y posttransplantation.

Real-life comparison of efficacy and safety profiles of two prolonged-release tacrolimus formulations in de novo kidney transplant recipients: 24 months of follow-up

INTRODUCTION

Calcineurin inhibitors constitute a cornerstone of immunosuppressive therapy in kidney transplant recipients. There are two main formulations of tacrolimus (Tac) which exhibit a prolonged-release mode of action: Advagraf® (MR-4) and Envarsus® (LCPT). However, they are not bioequivalent. Data comparing both once-daily prolonged-release formulations of Tac are insufficient.

OBJECTIVE

The aim of the study was to compare safety and efficacy profiles of once-daily LCPT and MR-4 formulations of tacrolimus in adult kidney transplant recipients.

PATIENTS AND METHODS

An observational, cohort single-center study was performed. One hundred fifteen kidney transplant recipients transplanted between 2016 and 2019 were enrolled to the study (59 vs 56, Envarsus® vs Advagraf®, respectively). Safety and efficacy profiles were assessed.

RESULTS

Patient and graft survival at 12 and 24 months did not differ between the groups. There were no significant differences in serum creatinine at any timepoint. C/D ratio in the LCPT group was significantly higher at 12 and 24 months. Sepsis occurrence was more frequent in MR-4 group at 12 months.

CONCLUSION

Both prolonged-release formulations of tacrolimus are safe and effective in immunosuppressive therapy in kidney transplant recipients.

Cost-Utility of Immunosuppressive Therapy Post-Renal Transplantation in Saudi Arabia: The Saudi Ministry of Health Perspective

OBJECTIVES

Chronic kidney disease is ranked fourth among the top 10 causes of death in Saudi Arabia. Renal transplantation has been recognized as the treatment of choice compared with long-term dialysis to maintain graft survival and prolong a patient's healthy living. Immunosuppressants (ISs) must be administered lifelong. The choice between IS therapies can be challenging because of the similarity in efficacy with some differences in adverse events profile. The objective of this study was to assess the cost-effectiveness of different IS regimens in Saudi Arabia.

METHODS

A 25-year Markov model was developed based on a previously published study from the Saudi Ministry of Health payer perspective. Efficacy parameters were driven from the literature, whereas cost data were estimated from the Ministry of Health database. A Monte Carlo simulation was conducted to test the base-case model results' robustness.

RESULTS

All comparators resulted in 6.2 quality-adjusted life-years (QALYs) except for Advagraf® treatment (5.5 QALYs). Generic tacrolimus plus mycophenolate mofetil (MMF) will cost 70 701.45 US dollars ($) (Saudi riyal 265 130.44) per patient to gain 6.2 QALYs over 25 years' time horizon. In the improved adherence scenario, Envarsus® plus generic MMF generated 9.6 QALYs with a cost of $59 849 per patient. Monte Carlo simulation results have shown that generic tacrolimus is still the cheapest treatment option compared with other treatment arms.

CONCLUSIONS

The current analysis suggested that all IS options are not cost-effective strategies relative to the willingness-to-pay threshold of $20 000. Nevertheless, Envarsus plus generic MMF regimen could become the most cost-effective regimen at different willingness-to-pay thresholds.

Comparative Study of 2 Extended-Release Tacrolimus Formulations in Kidney Transplantation

BACKGROUND

During the 1900s, tacrolimus became the mainstay immunosuppressive agent to prevent rejection after kidney transplant. Subsequently, an extended-release tacrolimus (ER-Tac) formulation was developed to improve adherence, and its generic version has been marketed over the last years. This study examines the differences in efficacy and safety between the generic ER-Tac (Conferoport) and the reference brand-name drug (Advagraf).

METHODS

Prospective, randomized and parallel single-center study (May 2020 to June 2021) with 52 kidney transplant recipients who were randomly assigned to 1 of the following groups: study group (Conferoport, n = 31) and control group (Advagraf, n = 21). The variables of interest were collected and analyzed to compare tacrolimus efficacy and safety between them. Demographic characteristics of the patients and clinical donor data were homogeneous in both groups (P > .05).

RESULTS

No statistically significant differences were found among treatments regarding dosage used, levels, creatinine, and proteinuria (P > .05), with these variables presenting a downward trend during follow-up and, consequently, the improvement of graft function. Analyses also revealed the absence of differences concerning the incidence of acute rejection and intrapatient variability (coefficient of variation) throughout the first year of evolution between both formulations (P > .05). A total of 5 graft losses occurred, 2 resulting from patient death.

CONCLUSIONS

In our experience, we found no significant differences between the measured parameters in relation to the efficacy and safety profile of both drugs, with generic ER-Tac being an alternative comparable with the reference brand-name ER-Tac.

Chronic kidney disease after lung transplantation in a changing era

Lung transplant (LTx) physicians are responsible for highly complex post-LTx care, including monitoring of kidney function and responding to kidney function loss. Better survival of the LTx population and changing patient characteristics, including older age and increased comorbidity, result in growing numbers of LTx patients with chronic kidney disease (CKD). CKD after LTx is correlated with worse survival, decreased quality of life and high costs. Challenges lie in different aspects of post-LTx renal care. First, serum creatinine form the basis for estimating renal function, under the assumption that patients have stable muscle mass. Low or changes in muscle mass is frequent in the LTx population and may lead to misclassification of CKD. Second, standardizing post-LTx monitoring of kidney function and renal care might contribute to slow down CKD progression. Third, new treatment options for CKD risk factors, such as diabetes mellitus, proteinuria and heart failure, have entered clinical practice. These new treatments have not been studied in LTx yet but are of interest for future use. In this review we will address the difficult aspects of post-LTx renal care and evaluate new and promising future approaches to slow down CKD progression.

Proposed Definitions of T Cell-Mediated Rejection and Tubulointerstitial Inflammation as Clinical Trial Endpoints in Kidney Transplantation

The diagnosis of acute T cell-mediated rejection (aTCMR) after kidney transplantation has considerable relevance for research purposes. Its definition is primarily based on tubulointerstitial inflammation and has changed little over time; aTCMR is therefore a suitable parameter for longitudinal data comparisons. In addition, because aTCMR is managed with antirejection therapies that carry additional risks, anxieties, and costs, it is a clinically meaningful endpoint for studies. This paper reviews the history and classifications of TCMR and characterizes its potential role in clinical trials: a role that largely depends on the nature of the biopsy taken (indication vs protocol), the level of inflammation observed (e.g., borderline changes vs full TCMR), concomitant chronic lesions (chronic active TCMR), and the therapeutic intervention planned. There is ongoing variability—and ambiguity—in clinical monitoring and management of TCMR. More research, to investigate the clinical relevance of borderline changes (especially in protocol biopsies) and effective therapeutic strategies that improve graft survival rates with minimal patient morbidity, is urgently required. The present paper was developed from documentation produced by the European Society for Organ Transplantation (ESOT) as part of a Broad Scientific Advice request that ESOT submitted to the European Medicines Agency for discussion in 2020. This paper proposes to move toward refined definitions of aTCMR and borderline changes to be included as primary endpoints in clinical trials of kidney transplantation.

Prolonged-Release Once-Daily Formulation of Tacrolimus Versus Standard-of-Care Tacrolimus in de novo Kidney Transplant Patients Across Europe

Background: Tacrolimus is the calcineurin inhibitor of choice for preventing acute rejection episodes in kidney transplant patients. However, tacrolimus has a narrow therapeutic range that requires regular monitoring of blood concentrations to minimize toxicity. A new once-daily tacrolimus formulation, LCP-tacrolimus (LCPT), has been developed, which uses MeltDose™ drug-delivery technology to control drug release and enhance overall bioavailability. Our study compared dosing of LCPT with current standard-of-care tacrolimus [immediate-release tacrolimus (IR-Tac) or prolonged-release tacrolimus (PR-Tac)] during the 6 months following de novo kidney transplantation. Comparisons of graft function, clinical outcomes, safety, and tolerability for LCPT versus IR-Tac/PR-Tac were also performed. Methods: Standard immunological risk patients with end-stage renal disease who had received a de novo kidney transplant were randomized (1:1) to LCPT (N = 200) or IR-Tac/PR-Tac (N = 201). Results: Least squares (LS) mean tacrolimus total daily dose from Week 3 to Month 6 was significantly lower for LCPT than for IR-Tac/PR-Tac. Although LS mean tacrolimus trough levels were significantly higher for LCPT than IR-Tac/PR-Tac, tacrolimus trough levels remained within the standard reference range for most patients. There were no differences between the groups in treatment failure measures or safety profile. Conclusion: LCPT can achieve similar clinical outcomes to other tacrolimus formulations, with a lower daily dose. Clinical Trial Registration: https://clinicaltrials.gov/, identifier NCT02432833.

BK Polyomavirus Nephropathy in Kidney Transplantation: Balancing Rejection and Infection

BK polyomavirus nephropathy (BKVN) and allograft rejection are two closely-associated diseases on opposite ends of the immune scale in kidney transplant recipients. The principle of balancing the immune system remains the mainstay of therapeutic strategy. While patient outcomes can be improved through screening, risk factors identification, and rapid reduction of immunosuppressants, a lack of standard curative therapy is the primary concern during clinical practice. Additionally, difficulty in pathological differential diagnosis and clinicopathology’s dissociation pose problems for a definite diagnosis. This article discusses the delicate evaluation needed to optimize immunosuppression and reviews recent advances in molecular diagnosis and immunological therapy for BKVN patients. New biomarkers for BKVN diagnosis are under development. For example, measurement of virus-specific T cell level may play a role in steering immunosuppressants. The development of cellular therapy may provide prevention, even a cure, for BKVN, a complex post-transplant complication.

Renal Function and Patient-Reported Outcomes in Stable Kidney Transplant Patients Following Conversion From Twice-Daily Immediate-Release Tacrolimus to Once-Daily Prolonged-Release Tacrolimus: A 12-Month Observational Study in Routine Clinical Practice in Germany (ADAGIO)

INTRODUCTION

This 12-month, noninterventional study on routine clinical practice in Germany evaluated renal function in stable kidney transplant recipients converted from immediate-release tacrolimus (IR-T) to prolonged-release tacrolimus (PR-T).

METHODS

Renal function was assessed in 183 patients by estimated glomerular filtration rate using the modification of diet in renal disease-4 formula. Self-reported gastrointestinal health-related quality of life, adherence, satisfaction with PR-T, suspected rejection episodes, and safety were also assessed at conversion and at 3, 6, and 12 months.

RESULTS

Conversion from IR-T to PR-T resulted in stable kidney function over 12 months, with a difference in estimated glomerular filtration rate between the first and final visits of 0.1 mL/min/1.73 m² (95% confidence interval, -1.6, 1.8). Eight patients experienced an acute rejection episode (4.4%). At each assessment, gastrointestinal health-related quality of life was low and adherence was high. Most patients reported that they were very satisfied (69.8%) or satisfied (28.1%) with PR-T at the final visit. Among patients reporting a preference, 78.4% preferred PR-T, 2.2% preferred IR-T, and 19.4% reported no preference. The safety profile of PR-T was consistent with that previously described.

CONCLUSION

Conversion of stable kidney transplant recipients from IR-T to PR-T provided stable kidney and graft function over 12 months (Verband Forschender Arzneimittelhersteller--registered study: NIS ADV-02).

Ten-Year Efficacy and Safety of Once-Daily Tacrolimus in Kidney Transplant: A Prospective Cohort Study

Tacrolimus is a cornerstone in the immunosuppressive therapy of kidney transplantation. The once-daily formulation of tacrolimus has been shown to improve adherence of patients without affecting short-term efficacy. However, long-term proof of once-daily tacrolimus efficacy and safety is still lacking. From January 2009 to November 2013, 170 clinically stable kidney transplant patients were offered to change from the ongoing twice-daily tacrolimus (TDT) formulation to a once-daily tacrolimus (ODT) regimen. Kidney transplant recipients agreeing to the change to be treated with an ODT regimen (n = 105, estimated glomerular filtration rate [eGFR] 57.1 ± 1.6 mL/min/1.73 m²) and patients continuing on a TDT formulation (n = 65, eGFR 52.0 ± 2.2 mL/min/1.73 m²) were prospectively followed (median follow-up time 10.4 and 12.6 years in the ODT and TDT groups, respectively, P = not significant). At the end of the follow-up, patients in both groups experienced similar eGFR (50.4 ± 2.2 vs 48.0 ± 2.7 mL/min/1.73 m² in the ODT and TDT groups, respectively, P = not significant). No differences were observed in biopsy-proven acute rejection, overall graft survival, doubling of serum creatinine, and new onset of proteinuria. The 2 groups also had a comparable rate of death, sepsis, and neoplasia. In conclusion, ODT appears safe and effective in stable kidney graft recipients even 10 years after transplantation. These findings support the use of ODT as a primary tacrolimus formulation in patients with kidney transplantation.

Adherence of Renal Transplant Recipients to Once-daily, Prolonged-Release and Twice-daily, Immediate-release Tacrolimus-based Regimens in a Real-life Setting in Sweden

BACKGROUND

In this study we investigated medication adherence of kidney transplant patients (KTPs) to an immediate-release tacrolimus (IR-T) regimen and, after conversion, to a prolonged-release tacrolimus (PR-T) regimen in routine clinical practice.

METHODS

This was a noninterventional, observational, multicenter Swedish study. We included adult KTPs with stable graft function, remaining on IR-T or converting from IR-T to PR-T. Data were collected at baseline, and months 3, 6, and 12 postbaseline. The primary endpoint was adherence using the Basel Assessment of Adherence to Immunosuppressive Medication Scale (BAASIS). Secondary assessments included tacrolimus dose and trough levels, clinical laboratory parameters (eg, estimated glomerular filtration rate), and adverse drug reactions (ADRs).

RESULTS

Overall, 233 KTPs were analyzed (PR-T, n = 175; IR-T, n = 58). Mean change in PR-T dose from baseline (4.8 mg/d) to month 12 was -0.2 mg/d, and for IR-T (4.2 mg/d) was -0.4 mg/d; tacrolimus trough levels remained similar. Overall adherence was similar between baseline and month 12 in both groups (PR-T: 54.4% vs 57.0%, respectively; IR-T: 65.5% vs 69.4%); timing adherence followed a similar pattern. The probability of taking adherence improved between baseline and month 12 (odds ratio, 1.97; P = .0092) in the PR-T group only. Mean BAASIS visual analog scale score at baseline was 94.3 ± 11.1% (PR-T) and 95.3 ± 7.6% (IR-T), and >95% at subsequent visits. Laboratory parameters remained stable. Eight (4.6%) patients receiving PR-T (none receiving IR-T) had ADRs considered probably/possibly treatment-related.

CONCLUSION

Disparity existed between high, patient-perceived and low, actual adherence. Overall adherence to the immunosuppressive regimen (measured by BAASIS) did not improve significantly over 12 months in stable KTPs converting to PR-T or remaining on IR-T; renal function remained stable.

Once-Daily versus Twice-Daily Tacrolimus in Kidney Transplantation: A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND

Tacrolimus is the most commonly prescribed medication in initial immunosuppressive regimens to prevent acute rejection in kidney transplant recipients (KTRs). Tacrolimus was originally available as an immediate-release formulation (IR-Tac) given twice daily. Extended-release tacrolimus (ER-Tac) given once daily was later developed with the expectation of improved medication adherence. Data from observational studies, which compared outcomes between ER-Tac and IR-Tac in different populations of KTRs including those who are unlikely to be enrolled in randomized clinical trials, have been reported.

PURPOSE

To evaluate the incidence of biopsy-proven acute rejection (BPAR) at 12 months together with other outcomes reported in observational studies among adult KTRs who received ER-Tac compared to IR-Tac.

METHODS

In accordance with the recommendations of the Cochrane Collaboration and the Meta-analysis of Observational Studies in Epidemiology, we systematically reviewed all observational studies that compared clinical outcomes between ER-Tac and IR-Tac in KTRs. The systematic searches were conducted on PubMed, EMBASE, Scopus, and Web of Science without language restriction. Reference lists were also searched and reviewed. Data were extracted for BPAR, graft survival, patient survival, estimated glomerular filtration rate (eGFR), serum creatinine (Scr), creatinine clearance (CrCl), at different times after kidney transplantation (KT). A meta-analysis was performed to integrate the results from the eligible studies. This study is registered with PROSPERO, number CRD42019135705.

RESULTS

From the 1401 articles screened, 10 observational studies in KTRs who received tacrolimus were included. The pooled results showed significantly lower BPAR with ER-Tac than with IR-Tac at 12 months post-KT (5 studies, n = 659; RR, 0.69; 95% CI 0.51-0.95; p = 0.02; I² = 0%). No significant differences in BPAR at other time points after KT were found. Graft survival, patient survival, Scr, and eGFR were comparable between groups at different times over approximately 1 year after transplantation.

CONCLUSIONS

Based upon currently available evidence in observational studies, 30% lower risk of BPAR was observed in ER-Tac group compared with IR-Tac group at 12 months post-KT, while there was no significant difference in BPAR risk at any other studied time points. No differences in graft- and patient-survival rates and kidney function were found. Given the limitations of observational studies to make causal inference, as well as quality limitations among the included studies, caution should be exercised in interpreting these findings.

Non-linear Relationship between Tacrolimus Blood Concentration and Acute Rejection After Kidney Transplantation: A Systematic Review and Dose-Response Meta-Analysis of Cohort Studies

BACKGROUND

Maintaining the exposure of tacrolimus (Tac) after kidney transplantation (KT) must be necessary to prevent acute rejection (AR) and improve graft survival，but there is still no clear consensus on the optimal Tac target blood concentration and concentration-effect relationship is poorly defined.

METHODS

We conducted a dose-response meta-analysis to quantitatively assess the association between Tac blood concentration and (AR) or adverse effects after KT. A comprehensive search of PubMed, Embase and Cochrane library databases was conducted to find eligible studies up to 10th September 2018. Unpublished data from patients receiving KT in West China Hospital (Sichuan University, China) were also collected. Both twostage dose-response and one-stage dose-response meta-analysis models were used to improve the statistical power.

RESULTS

A total of 4967 individuals from 10 original studies and 1453 individuals from West China Hospital were eligible for the ultimate analysis. In the two-stage dose-response meta-analysis model, we observed a significant non-linear relationship between Tac blood concentration and AR (P < 0.001) with moderate heterogeneity (I2 = 46.0%, P = 0.08). Tac blood concentration at 8ng/ml was associated with the lowest risk of AR (RR: 0.26, 95%CI: 0.13 - 0.54) by reference to 2ng/ml. Tac concentration at 7.0 - 11.0 ng/ml reduced the risk of AR by at least 70%, 5-14 ng/ml by at least 60%, and 4.5 - 14 ng/ml at least 50%. In the one-stage dose-response model, we also found a strong non-linear relationship between Tac and AR (P < 0.001) with moderate heterogeneity (I2 = 41.2%, P = 0.10). Tac concentration of 7.5 ng/ml was associated with the lowest risk of AR (RR: 0.35, 95%CI: 0.16 - 0.77). The blood concentration at 5.5 - 9.5 ng/ml was associated with the reduced AR by at least 60% and 4.5 - 10.5 ng/ml by at least 50% by reference to 2 ng/ml.

CONCLUSION

Maintaining Tac blood concentration at 5 - 9.5 ng/ml within the first year may prevent AR most effectively.

Mycophenolate mofetil, azathioprine and tacrolimus: mechanisms in rheumatology

The introduction of biologic DMARDs into rheumatology has resulted in a substantial reduction of the burden of many rheumatic diseases. In the slipstream of the success achieved with these biologic DMARDs, some conventional immunosuppressive drugs have also found use in new indications. Notably, mycophenolate mofetil, azathioprine and tacrolimus have made their way from solid organ transplantation drugs to become useful assets in rheumatology practice. Mycophenolate mofetil and azathioprine inhibit the purine pathway and subsequently diminish cell proliferation. Both drugs have a pivotal role in the treatment of various rheumatic diseases, including lupus nephritis. Tacrolimus inhibits lymphocyte activation by inhibiting the calcineurin pathway. Mycophenolate mofetil and tacrolimus are, among other indications, increasingly being recognized as useful drugs in the treatment of interstitial lung disease in systemic rheumatic diseases and skin fibrosis in systemic sclerosis. A broad array of trials with mycophenolate mofetil, azathioprine and/or tacrolimus are ongoing within the field of rheumatology that might provide further novel avenues for the use of these drugs. In this Review, we discuss the historical perspective, pharmacodynamics, clinical indications and novel avenues for mycophenolate mofetil, azathioprine and tacrolimus in rheumatology.

Long-Term Kidney Transplant Outcomes: Role of Prolonged-Release Tacrolimus

Tacrolimus has significantly improved outcomes for kidney transplant patients and remains the cornerstone of immunosuppressive therapy. While improvements in short-term outcomes in transplantation have been achieved in recent years, maintaining long-term graft survival remains a challenge in kidney transplantation. Minimizing risk factors for poor long-term kidney graft function and survival, and modifying tacrolimus regimens in the early and maintenance phases post-transplantation are essential to maintain long-term kidney transplant outcomes. Tacrolimus has a narrow therapeutic window, resulting in a tightly defined range of optimal drug exposure. Underimmunosuppression is associated with long-term risks, such as the development of donor-specific antibodies and antibody-mediated rejection, with a high possibility of a decline in kidney function and progression to graft failure. Conversely, prolonged overimmunosuppression carries a risk of drug-related adverse events. This review provides an overview of the differences in the formulation, delivery, and pharmacokinetic profiles between immediate- and prolonged-release tacrolimus and evaluates the effect of prolonged-release tacrolimus on the risk factors for poor outcomes in kidney transplantation. Recent evidence is used to provide guidance on target tacrolimus trough levels in the early and maintenance phases post-transplantation, with a view to improving long-term kidney graft function.

Clinically useful limited sampling strategy to estimate area under the concentration-time curve of once-daily tacrolimus in adult Japanese kidney transplant recipients

BACKGROUND

An extended-release, once-daily, oral formulation of tacrolimus is currently used after kidney transplantation as a substitute for the conventional twice-daily formulation. The purpose of this study was to provide a limited sampling strategy with minimum and optimum sampling points to predict the tacrolimus area under the concentration-time curve (AUC) after administration of once-daily tacrolimus in de novo adult kidney transplant patients.

METHODS

A total of 36 adult Japanese kidney transplant patients receiving once-daily tacrolimus were included: 31 were allocated to a study group to develop limited sampling strategy (LSS) model equations based on multiple stepwise linear regression analysis, and 5 were allocated to a validation group to estimate the precision of the LSS equations developed by the study group. Twelve-hour AUC (AUC0-12) was calculated by the trapezoidal rule, and the relationship between individual concentration points and AUC0-12 were determined by multiple linear regression analysis. The coefficient of determination (R2) was used to assess the goodness-of-fit of the regression models. Three error indices (mean error, mean absolute error, and root mean squared prediction error) were calculated to evaluate predictive bias, accuracy, and precision, respectively. Quality of the statistical models was compared with Akaike's information criterion (AIC).

RESULTS

A four-point model using C0, C2, C4 and C6 gave the best fit to predict AUC0-12 (R2 = 0.978). In the three- and two-point models, the best fits were at time points C2, C4, and C6 (R2 = 0.973), and C2 and C6 (R2 = 0.962), respectively. All three models reliably estimated tacrolimus AUC0-12, consistent with evaluations by the three error indices and Akaike's information criterion. Practically, the two-point model with C2 and C6 was considered to be the best combination, providing a highly accurate prediction and the lowest blood sampling frequency.

CONCLUSIONS

The two-point model with C2 and C6 may be valuable in reducing the burden on patients, as well as medical costs, for once-daily tacrolimus monitoring.

A Novel, Dose-Adjusted Tacrolimus Trough-Concentration Model for Predicting and Estimating Variance After Kidney Transplantation

Background and Objective

Given that a high intrapatient variability (IPV) of tacrolimus whole blood concentration increases the risk for a poor kidney transplant outcome, some experts advocate routine IPV monitoring for detection of high-risk patients. However, attempts to estimate the variance of tacrolimus trough concentrations (TTC) are limited by the need for patients to receive a fixed dose over time and/or the use of linear statistical models. A goal of this study is to overcome the current limitations through the novel application of statistical methodology generalizing the relationship between TTC and dose through the use of nonparametric functional regression modeling.

Methods

With TTC as a response and dose as a covariate, the model employs an unknown bivariate function, allowing for the potentially complex, nonlinear relationship between the two parameters. A dose-adjusted variance of TTC is then derived based on standard functional principal component analysis (FPCA). To assess the model, it was compared against an FPCA-based model and linear mixed-effects models using prediction error, bias, and coverage probabilities for simulated data as well as phase III data from the Astellas new drug application studies for extended-release tacrolimus.

Results

Our numerical investigation indicates that the new model better predicts dose-adjusted TTCs compared with the prediction of linear mixed effects models. Estimated coverage probabilities also indicate that the new model accurately accounts for the variance of TTC during the periods of large fluctuation in dose, whereas the linear mixed effects model consistently underestimates the coverage probabilities because of the inaccurate characterization of TTC fluctuation.

Conclusion

This is the first known application of a functional regression model to assess complex relationships between TTC and dose in a real clinical setting. This new method has applicability in future clinical trials including real-world data sets due to flexibility of the nonparametric modeling approach.

Electronic supplementary material

The online version of this article (10.1007/s40268-019-0271-2) contains supplementary material, which is available to authorized users.

Long-term, prolonged-release tacrolimus-based immunosuppression in de novo kidney transplant recipients: 5-year prospective follow-up of the ADHERE study patients

The objectives of this study were to assess long-term graft survival, patient survival, renal function, and acute rejections in de novo kidney transplant recipients, treated with once-daily prolonged-release tacrolimus-based therapy. The study was a 5-year non-interventional prospective follow-up of patients from the ADHERE study, a Phase IV 12-month open-label assessment of patients randomized to receive prolonged-release tacrolimus in combination with mycophenolate mofetil (MMF) (Arm 1) or sirolimus (Arm 2). From 838 patients in the randomized study, 587 were included in the long-term follow-up, of whom 510 completed the study at year 5. At 1 year post-transplant, graft and patient survival rates were 93.0% and 97.8%, respectively, and at 5 years were 84.0% and 90.8%, respectively. Cox proportional hazards analysis showed no association between graft loss, initial randomized treatment arm, donor age, donor type, or sex. The 5-year acute rejection-free survival rate was 77.4%, and biopsy-confirmed acute rejection-free survival rate was 86.0%. Renal function remained stable over the follow-up period: mean ± SD eGFR 4-variable modification diet in renal disease formula (MDRD4) was 52.3 ± 21.6 ml/min/1.73 m² at 6 months and 52.5 ± 23.0 ml/min/1.73 m² at 5 years post-transplant. These findings support the role of long-term once-daily prolonged-release tacrolimus-based immunosuppression, in combination with sirolimus or MMF, for renal transplant recipients in routine clinical practice.

Once-daily prolonged-release tacrolimus versus twice-daily tacrolimus in liver transplantation

OBJECTIVE

For patients who have received a kidney transplant, studies have shown that once-daily prolonged-release tacrolimus (TAC) has similar efficacy and safety to standard twice-daily dosing. The purpose of this study was to perform a meta-analysis to compare the effectiveness and safety of daily TAC (TAC qd) versus standard twice-daily TAC (TAC bid) administration in liver transplantation (LT).

DESIGN

Meta-analysis.

SETTING AND PARTICIPANTS

We systematically searched the PubMed/MEDLINE, Web of Science, and Cochrane Library databases for studies comparing outcomes of LT patients who received TAC qd versus TAC bid.

OUTCOME MEASURES

Results were reported as odds ratios (ORs) with 95% CIs.

RESULTS

Six studies, which included 5179 LT recipients (TAC qd = 951; TAC bid = 4228) were included in the analysis. The TAC qd group had a low 1-year graft loss rate (OR 0.70 [95% CI 0.54-0.91], P = 0.008) and lower rate of biopsy-proven acute rejection (BPAR) at 90 days (OR 0.46 [95% CI 0.24-0.89], P = 0.02) compared with the TAC bid group. There was no significant difference in 1-year mortality or the incidence of adverse events after LT between the 2 groups.

CONCLUSIONS

Current evidence suggests that TAC qd is safe and effective for LT patients during the first year after transplantation. Longer-term follow-up studies are necessary to determine if TAC qd is safe and effective beyond the first year after LT.

A Prospective, Observational Study of Conversion From Immediate- to Prolonged-Release Tacrolimus in Renal Transplant Recipients in France: The OPALE Study

Background

Potential benefits of once-daily, prolonged-release tacrolimus over the immediate-release formulation include improved adherence to immunosuppressives post transplantation. An observational study was performed to characterize real-world practice surrounding conversion from immediate- to prolonged-release tacrolimus in kidney transplant recipients.

Material/Methods

We performed a prospective, observational study of renal transplant recipients converted from immediate- to prolonged-release tacrolimus capsules. Conversion took place at the baseline visit, within the first 6 months of transplantation (early conversion group) or between 6 and 12 months of transplantation (late conversion group). Data collection was performed at routine follow-up at 6 and 12 months. Endpoints included conversion ratio from immediate- to prolonged-release tacrolimus, reasons for conversion, additional visits due to conversion, safety, and tolerability.

Results

The analysis population comprised 591 patients. Baseline characteristics were similar between the 2 groups. The mean conversion ratio of the daily dose of tacrolimus was 0.98±0.17 in the early group and 0.99±0.09 in the late group. Time from conversion (mean ±SD) to first measurement of trough tacrolimus blood concentration was 12.1±11.6 and 27.6±26.7 days in the early and late groups, respectively. The highest number of additional visits required was 6 in the early conversion group, in 3 patients (0.7%), and 3 in the late conversion group, in 2 patients (1.6%). Conversion from immediate- to prolonged-release tacrolimus was associated with a very low rate of graft rejection.

Conclusions

Favorable clinical outcomes and safety profiles were observed with conversion from immediate- to prolonged-release tacrolimus over 1 year following renal transplantation, with no marked differences between the early and late conversion groups.

Once- vs Twice-Daily Tacrolimus: Survival Rates and Side Effects: Single-Center Experience

BACKGROUND

This study aimed to determine whether de novo, prolonged-release tacrolimus- (PR-tacro) based immunosuppressive regimen affected graft and patient survival when compared to an immediate-release, twice-daily, tacrolimus- (IR-tacro) based regimen in kidney transplant recipients. We also aimed to determine the difference between the frequency of side effects, including diabetes control, in study groups.

METHODS

A total of 115 standard risk kidney transplant recipients were enrolled in this single center, retrospective study. Fifty-two patients received PR-tacro and 63 patients received IR-tacro as a calcineurin inhibitor. The primary outcome measures included incidence of graft loss and delayed graft function (DGF), biopsy-proven acute rejection , graft and patient survival, and creatinine clearance. Secondary outcome measures included the incidence of non-adherence, drug-induced tremor; post-transplant diabetes mellitus diagnosis rate; and control of diabetes in pre-transplant diabetic patients.

RESULTS

Baseline characteristics and mean tacrolimus trough levels were comparable between groups. Incidence of graft loss, DGF, and graft and patient survival were similar between groups (P > .05). Mean creatinine clearance level was also similar (P > .05). Mean serum levels of fasting glucose (P < .05) and A1C (P < .05) were lower in PR-tacro group when compared to IR-tacro group. Post-transplant diabetes mellitus diagnosis rate was also lower in PR-tacro group when compared to IR-tacro group (P = .040).

CONCLUSION

This study suggests that there is no statistically significant difference between PR-tacro and IR-tacro in terms of patient and graft survival, DGF, and biopsy-proven acute rejection rates in kidney transplant recipients. Post-transplant diabetes mellitus frequency is lower in non-diabetic patients, and glucose metabolism control is better in diabetic patients.

Improvement of medication adherence with simplified once-daily immunosuppressive regimen in stable kidney transplant recipients: A prospective cohort study

BACKGROUND

Many immunosuppressive drugs are prescribed as twice-daily dosing. A simplified once-daily dosing of immunosuppressive drug regimen may improve medication adherence. We investigated medication adherence of simplified once-daily immunosuppressive regimen consisting of extended-release tacrolimus, sirolimus, and corticosteroids along with the efficacy and safety of this regimen.

METHODS

This study was a prospective, multicenter, controlled and cohort trial. Stable kidney transplant recipients who had received transplantation at least 3 months before the study enrollment were eligible for the study. Participants were required to fill-out the self-reported immunosuppressant therapy barrier scale (ITBS) questionnaire before and after the conversion. Other clinical laboratory parameters and adverse events were evaluated until 6 months post-conversion.

RESULTS

A total of 160 kidney recipients comprised the intention-to-treat population. The mean total ITBS score was 19.5 ± 4.0 at pre-conversion and 6 months after converting, the mean total ITBS score was 16.6 ± 3.6 (p < 0.001). Particularly, the ITBS scores of 4 questions related to the frequency of medication dosing were significantly different between pre-conversion and post-conversion. Only 1 patient (0.62%) was diagnosed as biopsy-confirmed acute rejection in the study period. There was no significant change in the mean estimated glomerular filtration rate after the conversion. Overall 95 patients (59.4%) had an adverse event and 28 patients (17.5%) had a serious adverse event. No graft loss and 1 death were reported.

CONCLUSION

Medication adherence after the conversion to the once-daily immunosuppressive regimen was significantly improved with no additional risks of efficacy failure or adverse events.

A non-randomized trial of conversion from ciclosporin and tacrolimus to tacrolimus MR4 in stable long-term kidney transplant recipients: Graft function and influences of ABCB1 genotypes

TRIAL REGISTRATION

PEP Study: Ethics committee N° 393/2004, EudraCT 2004-004209-98. PEP-X Study: Ethics committee amendment application N° 154/01/2008. ClinicalTrials.gov NCT03751332.

Population pharmacokinetics of immediate- and prolonged-release tacrolimus formulations in liver, kidney and heart transplant recipients

Aims

Develop a population pharmacokinetics model of tacrolimus in organ transplant recipients receiving twice‐daily, immediate‐release (IR‐T; Prograf) and/or once‐daily, prolonged‐release (PR‐T; Advagraf or Astagraf XL) tacrolimus.

Methods

Tacrolimus concentration–time profiles were analysed from 8 Phase II studies in adult and paediatric liver, kidney and heart transplant patients receiving IR‐T and/or PR‐T. A tacrolimus population pharmacokinetic model, including identification of significant covariates, was developed using NONMEM.

Results

Overall, 23,176 tacrolimus concentration records were obtained from 408 patients. A 2‐compartment model with first‐order absorption and elimination described the concentration–time profiles. Tacrolimus absorption rate was 50% slower with PR‐T vs IR‐T. Tacrolimus apparent oral clearance was 44.3 L/h in Whites and 59% higher in Asians. Tacrolimus central volume of distribution was 108 L in males and 55% lower in females; trough concentrations were similar between formulations. Tacrolimus relative bioavailability was similar between formulations (geometric mean ratio PR‐T:IR‐T 95%, 90% confidence intervals: 89%, 101%). Asians had 83% and 51% higher relative bioavailability than Whites and Blacks, respectively, for IR‐T and PR‐T. Whites had 49% and 77% higher relative bioavailability than Blacks for PR‐T and IR‐T, respectively. Blacks had 52% lower relative bioavailability than Whites and Asians for IR‐T and PR‐T. Type of organ transplanted and patient population (adult/paediatric) did not have a significant effect on tacrolimus pharmacokinetics.

Conclusions

This population pharmacokinetic model described data from transplant recipients who received IR‐T and/or PR‐T. Tacrolimus trough concentrations and relative bioavailability were similar between formulations, supporting 1 mg:1 mg conversion from Prograf to Advagraf/Astagraf XL in clinical practice.

Real-World Study of Once-Daily, Extended-Release Tacrolimus Versus Twice-Daily, Immediate-Release Tacrolimus in Kidney Transplantation: Clinical Outcomes and Healthcare Resource Utilization

INTRODUCTION

Real-world data with extended-release tacrolimus (ER-T) are lacking in the USA. This study examined clinical outcomes and healthcare resource utilization in kidney transplant patients receiving ER-T in clinical practice.

METHODS

This was a retrospective, single-center analysis (February-June 2016) using data from Northwestern University's Enterprise Data Warehouse. Adult patients receiving a kidney transplant in the preceding 4 years, treated de novo or converted to ER-T from immediate-release tacrolimus (IR-T) within 10 days post-transplantation, and maintained on ER-T (at least 3 months) were included. Patients were matched for demographic and clinical characteristics with IR-T-treated control patients. Endpoints included clinical outcomes and healthcare resource utilization up to 1 year post-transplantation.

RESULTS

A total of 19 ER-T-treated patients were matched with 55 IR-T-treated patients. No ER-T-treated patients experienced biopsy-confirmed acute rejection (BCAR) or graft failure versus 3 (5.5%) and 3 (5.5%) IR-T-treated patients, respectively. Mean estimated glomerular filtration rate (eGFR), the number of all-cause outpatient visits, readmissions, and all-cause hospitalization days were comparable between groups. Tacrolimus trough levels, days to target level (6-10 ng/mL), and number of required dose adjustments were also similar.

CONCLUSION

Real-world clinical outcomes and healthcare resource utilization were similar with ER-T and IR-T. Larger studies will need to investigate the trend toward fewer BCAR events, and increased graft survival with ER-T.

FUNDING

Astellas Pharma Global Development, Inc. Plain language summary available for this article.

Envarsus, a novelty for transplant nephrologists: Observational retrospective study

The aim of this study was to evaluate the trough concentrations (Cp_trough) and the tacrolimus dosage regimen after the conversion of Prograf or Advagraf to Envarsus (new pharmaceutical form with MeltDose technology that improves the absorption of fat-soluble drugs) in patients with stable renal transplantation, and their renal function. We selected stable renal transplant patients who were converted to Envarsus. Two periods were defined: Baseline and Conversion (Envarsus) and they were stratified according to the pharmaceutical form used in the Baseline period. Sixty-one patients were included (24 with Advagraf and 37 with Prograf), with an average age of 52years. The mean post-transplant time at the time of conversion to Envarsus was 76.3months and the mean follow-up in the Baseline and Conversion period was 10.1months and 11.6months, respectively. In the Prograf and Envarsus group, the Cp_trough medians were 6.6 vs 6.4 ng/mL (P=.636), with a mean daily dose that decreased significantly from 3mg to 2mg (P<.001), respectively, maintaining the filtration rate. The median Cp_trough values in the Advagraf and Envarsus groups were 5.7ng/mL and 6.3ng/mL (P=.07), with a median daily dose of 7mg and 4mg (P<.001), respectively, and the same renal function. In stable renal transplant patients, the conversion from Advagraf to Envarsus has allowed the dose of tacrolimus to be reduced by 42.9% and, in the case of Prograf, by 33.3%, maintaining similar Cp_trough values, without renal function being altered.

Pharmacokinetics of Prolonged-Release Once-Daily Formulations of Tacrolimus in De Novo Kidney Transplant Recipients: A Randomized, Parallel-Group, Open-Label, Multicenter Study

INTRODUCTION

Different prolonged-release formulations of tacrolimus are available. To date, the pharmacokinetic (PK) profile of LCP-tacrolimus (LCPT; Envarsus^®) has not been compared with PR-Tac (Advagraf^®) in de novo kidney transplant recipients. These profiles will guide clinical recommendations for the initiation and dose titration strategies of once-daily tacrolimus formulations.

METHODS

This randomized, parallel-group, open-label, multicenter PK study randomized 75 de novo, adult, white kidney transplant recipients to LCPT 0.17 mg/kg/day (n = 37) or PR-Tac 0.20 mg/kg/day (n = 38) for 4 weeks. Dose adjustments were permitted to target a pre-defined therapeutic range based on measured trough blood concentrations.

RESULTS

PK analysis (days 1, 3, 7 and 14) included 68 patients (LCPT, n = 33; PR-Tac, n = 35). Similar proportions of patients were within the pre-defined therapeutic tacrolimus trough blood concentration range, with < 12% in each group having below-target trough levels over the study period. LCPT demonstrated ~ 30% greater relative bioavailability [LCPT/PR-Tac adjusted geometric mean ratio: day 3, 1.32 (p = 0.007); day 7, 1.25 (p = 0.051); day 14, 1.43 (p = 0.002)] and ~ 30% lower peak-to-trough percentage fluctuation of blood concentration [LCPT/PR-Tac adjusted geometric mean ratio: day 3, 0.70 (p < 0.001); day 7, 0.68 (p < 0.001); day 14, 0.73 (p = 0.004)] in addition to longer time to maximum blood concentration (t_max), lower maximum concentration (C_max) and a consistently lower daily dose (~ 40% dose reduction with LCPT vs. PR-Tac by day 28). Safety profiles were similar.

CONCLUSION

In de novo kidney transplant recipients, prolonged-release formulations of tacrolimus can reach therapeutic concentrations in the immediate post-transplant period. LCPT has greater relative bioavailability and lower peak-to-trough fluctuation compared with PR-Tac.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov; study number NCT02500212.

FUNDING

Chiesi Farmaceutici S.p.A.

Prolonged-Release vs Immediate-Release Tacrolimus Capsules in Black vs White Kidney Transplant Patients: A Post Hoc Analysis of Phase III Data

BACKGROUND

Black kidney transplant patients experience inferior outcomes compared with other ethnicities. Because scrutiny is required when immunosuppressant drugs are used in such at-risk populations, we report the first large-scale clinical efficacy data assessing prolonged-release tacrolimus (PR-T) in black de novo kidney transplant patients.

METHODS AND MATERIALS

We used logistic regression and proportionate hazards to compare a composite outcome measure (biopsy-proven acute rejection, graft loss, mortality, and loss to follow-up) in black and white patients in treatment groups longer than 24 weeks, from 3 large Phase III randomized controlled trials. Secondary endpoints included tacrolimus trough concentration, dose, and estimated glomerular filtration rate.

RESULTS

The study included 2162 patients whose treatments belonged to two categories (immediate-release tacrolimus: 77 black patients, 721 white patients; and PR-T: 87 black patients, 1277 white patients). Despite demographic factors generally predictive of worse outcomes, efficacy failure among black patients who received PR-T was non-inferior to that among white patients who received either therapy. Compared with immediate-release tacrolimus, black patients who received PR-T achieved stable tacrolimus concentrations 2.5 times faster (21 vs 56 days, P = .04), and more achieved stable target concentrations (76.7% vs 69.3%). Treatment-emergent adverse events were consistent with those reported separately in pivotal trials.

CONCLUSIONS

Overall, black patients who received PR-T achieved non-inferior outcomes compared to white patients, despite higher pretransplant risk among black patients. Moreover, PR-T improved the time to achieve, and the likelihood of reaching, stable therapeutic concentrations among black patients, suggesting that PR-T could improve the consistency of tacrolimus exposure in this patient population.

Early Versus Late Conversion From Immediate to Prolonged-Release Tacrolimus After Renal Transplantation: Clinical Effects and Treatment Costs

Introduction

Prolonged-release tacrolimus (PR-TAC) was associated with improved renal function after transplantation when compared to immediate-release tacrolimus (IR-TAC) although evidence is still scarce. This study aimed to compare clinical outcomes and treatment costs in patients who converted from IR-TAC to PR-TAC during the first year after renal transplantation (RT) (early converters [EC]) or after that period (late converters [LC]).

Methods

We performed a retrospective study including 79 patients (EC, 39; LC, 41) which were followed up over 60 months. A mixed-effects approach was used to investigate the differences between both groups regarding renal and metabolic outcomes as well as treatment costs.

Results

The median time from RT to conversion was 3 months for EC and 25 months for LC. For both EC and LC, a significant increase in estimated glomerular filtration rate was observed after conversion (5.2 and 4.9 mL/min per 1.73 m², respectively). During the first year after RT, EC presented a higher estimated glomerular filtration rate and inferior tacrolimus trough levels when compared to LC, with higher mean treatment costs associated. However, thereafter, these outcomes were similar between groups over the remaining time. At the end of follow-up, no significant differences were found regarding allograft acute rejection (2.6% and 2.4%), new-onset diabetes (15.7% vs 12.2%) or cardiovascular events (5.2% vs 7.3%).

Conclusions

There was a significant benefit on renal function after conversion from IR-TAC to PR-TAC. During the first year after RT, EC presented improved renal function, but higher treatment costs. None of these differences persisted at the end of follow-up.

Once-daily vs twice-daily tacrolimus for de novo living kidney transplantation patients including ABO/HLA compatible and incompatible: A randomized trial

Tacrolimus (TAC) is available as a twice-daily capsule (TAC-BID), once-daily capsule (TAC-QD), and once-daily tablet. Recipients with ABO-incompatible/anti-human leukocyte antigen (HLA)-incompatible transplantation were excluded in previous trials and have thus not been evaluated. We conducted a 5-year trial to determine whether TAC-QD is noninferior to TAC-BID for transplant outcomes. Adults who underwent de novo living kidney transplantation were randomly assigned (62 TAC-QD; 63 TAC-BID). We did not exclude ABO-/HLA- incompatible transplantation. TAC was initiated 7 days preoperatively (0.10 mg/kg/d). Mycophenolate mofetil, methylprednisolone, and basiliximab were administered. The primary endpoint was graft failure (non-censored for death). We performed a noninferiority test. The noninferiority margin was 10% in risk difference. Five-year graft failure rates were 6.5% and 9.5% for TAC-QD and TAC-BID, respectively (noninferiority, P = 0.009). The estimated glomerular filtration rates were similar between the groups (noninferiority, P < 0.001). TAC-QD did not have point estimates of risk difference above the inferiority margin in any assessed endpoints. However, a tendency of interaction was observed between biopsy-proven acute rejection and the follow-up period. In a living kidney transplant population with 40% of patients with ABO/HLA incompatibility, the effect of TAC-QD was not appreciably worse on various clinical transplant outcomes than that of TAC-BID over 5 years.

Long-lasting immunosuppressive effects of tacrolimus-loaded micelle NK61060 in preclinical arthritis and colitis models

AIM

Tacrolimus (TAC) is an important drug for inflammatory diseases. However, TAC has several limitations, such as variable trough concentrations among individuals and a high medication frequency. In this study, we created NK61060, a novel micellar TAC formulation, to circumvent these disadvantages.

MATERIALS & METHODS

Immunosuppressive activity of NK61060 was determined in the collagen-induced arthritis rat model, mannan-induced arthritis mouse model and dextran sodium sulfate-induced colitis mouse model. The pharmacokinetics and toxicology of NK61060 were evaluated in those models.

RESULTS

In arthritis and colitis models, NK61060 exhibited superior immunosuppressive activity compared with that of TAC. Pharmacokinetic and toxicological analyses indicated that NK61060 had a wider safety margin and could be administered at a reduced medication frequency.

CONCLUSION

NK61060 mitigates the trough concentration variability and the medication frequency and it may be a safer and more effective option for use in clinical settings. Further studies are needed to determine its clinical usefulness.

Extended release versus immediate release tacrolimus in kidney transplant recipients: a systematic review and meta-analysis

PURPOSE

To compare the estimated glomerular filtration rate (eGFR) at 12 months together with other outcomes among adult kidney transplant recipients (KTRs) who received extended release, once daily tacrolimus (ER-Tac) compared to those who received the immediate release, twice daily tacrolimus (IR-Tac) administration.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement, we systematically reviewed all randomized controlled trials (RCTs) that compared clinical outcomes between ER-Tac versus IR-Tac in KTRs. The systematic searches were conducted on PubMed, EMBASE, Cochrane Register of Controlled Trials, Scopus, Web of Science, and CINAHL without language restriction. The trials registered and reference lists were also searched and reviewed. Data were extracted for eGFR, serum creatinine (Scr), creatinine clearance (CrCl), biopsy-proven acute rejection rate (BPAR), graft survival, and overall patient survival at different times over 24 months after kidney transplant (KT). A meta-analysis was performed to integrate the results from eligible studies.

RESULTS

From 1145 articles screened, 11 RCTs were included. The pooled results of included RCTs showed no significant difference of eGFR at 12 months between ER-Tac and IR-Tac groups (four trials, n = 1738; mean difference - 0.77 mL/min/1.73 m2, 95% CI: - 2.41 to 0.87; p = 0.56; I2 = 0%). Comparing between the two tacrolimus formulations, there were no significant differences of eGFR, CrCl, Scr, BPAR, graft survival, and patient survival at different times over 4 years after transplantation.

CONCLUSIONS

Based upon currently available evidences in KTRs, the impact on kidney allograft function appears to be comparable between ER-Tac and IR-Tac.

Once-daily, prolonged-release tacrolimus vs twice-daily, immediate-release tacrolimus in de novo living-donor liver transplantation: A Phase 4, randomized, open-label, comparative, single-center study

Randomized, open-label, comparative, single-center, Phase 4, 24-week study comparing pharmacokinetics (PK), safety, and efficacy of once-daily, prolonged-release tacrolimus (PR-T) with twice-daily, immediate-release tacrolimus (IR-T) in adult de novo living-donor liver transplant (LDLT) recipients in Korea. All patients received intravenous tacrolimus from Day 0 (transplantation) for 4 days and were randomized (1:1) to receive oral PR-T or IR-T from Day 5. PK profiles were taken on Days 6 and 21. Primary endpoint: area under the concentration-time curve over 24 hour (AUC_0-24 ). Predefined similarity interval for confidence intervals of ratios: 80%-125%. Secondary endpoints included: tacrolimus concentration at 24 hour (C₂₄ ), patient/graft survival, biopsy-confirmed acute rejection (BCAR), treatment-emergent adverse events (TEAEs). One-hundred patients were included (PR-T, n = 50; IR-T, n = 50). Compared with IR-T, 40% and 66% higher mean PR-T daily doses resulted in similar AUC_0-24 between formulations on Day 6 (PR-T:IR-T ratio of means 96.8%), and numerically higher AUC_0-24 with PR-T on Day 21 (128.8%), respectively. Linear relationship was similar between AUC_0-24 and C₂₄ , and formulations. No graft loss/deaths, incidence of BCAR and TEAEs similar between formulations. Higher PR-T vs IR-T doses were required to achieve comparable systemic exposure in Korean de novo LDLT recipients. PR-T was efficacious; no new safety signals were detected.

Adherence to and Acceptance of Once-Daily Tacrolimus After Kidney and Liver Transplant: Results From OSIRIS, a French Observational Study

BACKGROUND

Adherence to immunosuppressive treatments is a major concern in transplanted patients.

METHODS

This 6-month French observational, longitudinal, prospective study aimed to assess patient adherence to and acceptance of once-daily tacrolimus (Advagraf) initiation in kidney and liver transplant recipients. Data from 1106 patients initiating once-daily tacrolimus during posttransplant follow-up were analyzed. Adherence and acceptance were assessed using self-administered questionnaires at inclusion and at 3 and 6 months.

RESULTS

Mean age was 52.4 ± 13.2 years, 61.5% were men. For 94.9% of patients, once-daily tacrolimus was prescribed after switching from twice-daily tacrolimus. At inclusion, 20.9% of patients reported good treatment adherence, 72.0% minor nonadherence, and 7.1% were nonadherent. Mean general acceptance score (range, 0-100) was 77.7 (±24.7). At 3 months, adherence was improved in 21.1%, unchanged in 69.2%, and worsened in 9.7% of patients. Mean general acceptance score was 75.4 (±26.5). General acceptance score was improved in 28.0%, unchanged in 39.4%, and worsened in 32.7% of patients. At 6 months, similar changes in adherence and acceptance were observed. Higher general acceptance score at month 3 was significantly associated with better adherence at month 6.

CONCLUSIONS

Conversion to once-daily tacrolimus led to an improved rate of adherence at month 3 in more than 20% of patients and a worsened rate of adherence in less than 10% of patients.

Immunosuppressive therapy for kidney transplantation in adults: a systematic review and economic model

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring renal replacement therapy: kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation, followed by immunosuppressive therapy (induction and maintenance therapy) to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect(®), Novartis Pharmaceuticals UK Ltd) and rabbit anti-human thymocyte immunoglobulin (rATG) (Thymoglobulin(®), Sanofi) as induction therapy, and immediate-release tacrolimus (TAC) (Adoport(®), Sandoz; Capexion(®), Mylan; Modigraf(®), Astellas Pharma; Perixis(®), Accord Healthcare; Prograf(®), Astellas Pharma; Tacni(®), Teva; Vivadex(®), Dexcel Pharma), prolonged-release tacrolimus (Advagraf(®) Astellas Pharma), belatacept (BEL) (Nulojix(®), Bristol-Myers Squibb), mycophenolate mofetil (MMF) (Arzip(®), Zentiva; CellCept(®), Roche Products; Myfenax(®), Teva), mycophenolate sodium (MPS) (Myfortic(®), Novartis Pharmaceuticals UK Ltd), sirolimus (SRL) (Rapamune(®), Pfizer) and everolimus (EVL) (Certican(®), Novartis) as maintenance therapy in adult renal transplantation.

METHODS

Clinical effectiveness searches were conducted until 18 November 2014 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science (via ISI), Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted until 18 November 2014 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Database (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and the American Economic Association's electronic bibliography (via EconLit, EBSCOhost). Included studies were selected according to predefined methods and criteria. A random-effects model was used to analyse clinical effectiveness data (odds ratios for binary data and mean differences for continuous data). Network meta-analyses were undertaken within a Bayesian framework. A new discrete time-state transition economic model (semi-Markov) was developed, with acute rejection, graft function (GRF) and new-onset diabetes mellitus used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Eighty-nine randomised controlled trials (RCTs), of variable quality, were included. For induction therapy, no treatment appeared more effective than another in reducing graft loss or mortality. Compared with placebo/no induction, rATG and BAS appeared more effective in reducing biopsy-proven acute rejection (BPAR) and BAS appeared more effective at improving GRF. For maintenance therapy, no treatment was better for all outcomes and no treatment appeared most effective at reducing graft loss. BEL + MMF appeared more effective than TAC + MMF and SRL + MMF at reducing mortality. MMF + CSA (ciclosporin), TAC + MMF, SRL + TAC, TAC + AZA (azathioprine) and EVL + CSA appeared more effective than CSA + AZA and EVL + MPS at reducing BPAR. SRL + AZA, TAC + AZA, TAC + MMF and BEL + MMF appeared to improve GRF compared with CSA + AZA and MMF + CSA. In the base-case deterministic and probabilistic analyses, BAS, MMF and TAC were predicted to be cost-effective at £20,000 and £30,000 per quality-adjusted life-year (QALY). When comparing all regimens, only BAS + TAC + MMF was cost-effective at £20,000 and £30,000 per QALY.

LIMITATIONS

For included trials, there was substantial methodological heterogeneity, few trials reported follow-up beyond 1 year, and there were insufficient data to perform subgroup analysis. Treatment discontinuation and switching were not modelled.

FUTURE WORK

High-quality, better-reported, longer-term RCTs are needed. Ideally, these would be sufficiently powered for subgroup analysis and include health-related quality of life as an outcome.

CONCLUSION

Only a regimen of BAS induction followed by maintenance with TAC and MMF is likely to be cost-effective at £20,000-30,000 per QALY.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013189.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Immunosuppressive therapy for kidney transplantation in children and adolescents: systematic review and economic evaluation

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation followed by induction and maintenance immunosuppressive therapy to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To systematically review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect,(®) Novartis Pharmaceuticals) and rabbit antihuman thymocyte immunoglobulin (Thymoglobuline,(®) Sanofi) as induction therapy and immediate-release tacrolimus [Adoport(®) (Sandoz); Capexion(®) (Mylan); Modigraf(®) (Astellas Pharma); Perixis(®) (Accord Healthcare); Prograf(®) (Astellas Pharma); Tacni(®) (Teva); Vivadex(®) (Dexcel Pharma)], prolonged-release tacrolimus (Advagraf,(®) Astellas Pharma); belatacept (BEL) (Nulojix,(®) Bristol-Myers Squibb), mycophenolate mofetil (MMF) [Arzip(®) (Zentiva), CellCept(®) (Roche Products), Myfenax(®) (Teva), generic MMF is manufactured by Accord Healthcare, Actavis, Arrow Pharmaceuticals, Dr Reddy's Laboratories, Mylan, Sandoz and Wockhardt], mycophenolate sodium, sirolimus (Rapamune,(®) Pfizer) and everolimus (Certican,(®) Novartis Pharmaceuticals) as maintenance therapy in children and adolescents undergoing renal transplantation.

DATA SOURCES

Clinical effectiveness searches were conducted to 7 January 2015 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science [via Institute for Scientific Information (ISI)], Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (HTA) (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted to 15 January 2015 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Databases (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and EconLit (via EBSCOhost).

REVIEW METHODS

Titles and abstracts were screened according to predefined inclusion criteria, as were full texts of identified studies. Included studies were extracted and quality appraised. Data were meta-analysed when appropriate. A new discrete time state transition economic model (semi-Markov) was developed; graft function, and incidences of acute rejection and new-onset diabetes mellitus were used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Three randomised controlled trials (RCTs) and four non-RCTs were included. The RCTs only evaluated BAS and tacrolimus (TAC). No statistically significant differences in key outcomes were found between BAS and placebo/no induction. Statistically significantly higher graft function (p < 0.01) and less biopsy-proven acute rejection (odds ratio 0.29, 95% confidence interval 0.15 to 0.57) was found between TAC and ciclosporin (CSA). Only one cost-effectiveness study was identified, which informed NICE guidance TA99. BAS [with TAC and azathioprine (AZA)] was predicted to be cost-effective at £20,000-30,000 per quality-adjusted life year (QALY) versus no induction (BAS was dominant). BAS (with CSA and MMF) was not predicted to be cost-effective at £20,000-30,000 per QALY versus no induction (BAS was dominated). TAC (with AZA) was predicted to be cost-effective at £20,000-30,000 per QALY versus CSA (TAC was dominant). A model based on adult evidence suggests that at a cost-effectiveness threshold of £20,000-30,000 per QALY, BAS and TAC are cost-effective in all considered combinations; MMF was also cost-effective with CSA but not TAC.

LIMITATIONS

The RCT evidence is very limited; analyses comparing all interventions need to rely on adult evidence.

CONCLUSIONS

TAC is likely to be cost-effective (vs. CSA, in combination with AZA) at £20,000-30,000 per QALY. Analysis based on one RCT found BAS to be dominant, but analysis based on another RCT found BAS to be dominated. BAS plus TAC and AZA was predicted to be cost-effective at £20,000-30,000 per QALY when all regimens were compared using extrapolated adult evidence. High-quality primary effectiveness research is needed. The UK Renal Registry could form the basis for a prospective primary study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013544.

FUNDING

The National Institute for Health Research HTA programme.

High frequency of valganciclovir underdosing for cytomegalovirus prophylaxis after renal transplantation

Background

The correct valganciclovir dose for cytomegalovirus (CMV) prophylaxis depends on renal function estimated by the Cockcroft–Gault (CG) estimated creatinine clearance (CG-CrCl) formula. Patients with delayed or rapidly changing graft function after transplantation (tx) will need dose adjustments.

Methods

We performed a retrospective investigation of valganciclovir dosing in renal transplant patients receiving CMV prophylaxis between August 2003 and August 2011, and analysed valganciclovir dosing, CG-CrCl, CMV viraemia (CMV-PCR <750 copies/mL), leucopenia (<3500/µL) and neutropenia (<1500/µL) in the first year post-transplant. On Days 30 and 60 post-transplant, dosing pattern in relation to estimated creatinine clearance was analysed regarding CMV viraemia, leucopenia and neutropenia.

Results

Six hundred and thirty-five patients received valganciclovir prophylaxis that lasted 129 ± 68 days with a mean dose of 248 ± 152 mg/day of whom 112/635 (17.7%) developed CMV viraemia, 166/635 (26.1%) leucopenia and 48/635 (7.6%) neutropenia. CMV resistance within 1 year post-transplant was detected in three patients. Only 137/609 (22.6%) patients received the recommended dose, while n = 426 (70.3%) were underdosed and n = 43 (7.1%) were overdosed at Day 30 post-tx. Risk factors for CMV viraemia were donor positive D (+)/receptor negative R (−) status and short prophylaxis duration, but not low valganciclovir dose. Risk factors for developing leucopenia were D+/R− status and low renal function. No significant differences in dosing frequency were observed in patients developing neutropenia or not (P = 0.584).

Conclusion

Most patients do not receive the recommended valganciclovir dose. Despite obvious underdosing in a large proportion of patients, effective prophylaxis was maintained and it was not associated as a risk factor for CMV viraemia or leucopenia.

Results of ASERTAA, a Randomized Prospective Crossover Pharmacogenetic Study of Immediate-Release Versus Extended-Release Tacrolimus in African American Kidney Transplant Recipients

BACKGROUND

Differences in tacrolimus dosing across ancestries is partly attributable to polymorphisms in CYP3A5 genes that encode tacrolimus-metabolizing cytochrome P450 3A5 enzymes. The CYP3A5*1 allele, preponderant in African Americans, is associated with rapid metabolism, subtherapeutic concentrations, and higher dose requirements for tacrolimus, all contributing to worse outcomes. Little is known about the relationship between CYP3A5 genotype and the tacrolimus pharmacokinetic area under the curve (AUC) profile in African Americans or whether pharmacogenetic differences exist between conventional twice-daily, rapidly absorbed, immediate-release tacrolimus (IR-Tac) and once-daily extended-release tacrolimus (LifeCycle Pharma Tac [LCPT]) with a delayed absorption profile.

STUDY DESIGN

Randomized prospective crossover study.

SETTING & PARTICIPANTS

50 African American maintenance kidney recipients on stable IR-Tac dosing.

INTERVENTION

Recipients were randomly assigned to continue IR-Tac on days 1 to 7 and then switch to LCPT on day 8 or receive LCPT on days 1 to 7 and then switch to IR-Tac on day 8. The LCPT dose was 85% of the IR-Tac total daily dose.

OUTCOMES

Tacrolimus 24-hour AUC (AUC_0-24), peak and trough concentrations (C_max and C_min), time to peak concentration, and bioavailability of LCPT versus IR-Tac, according to CYP3A5 genotype.

MEASUREMENTS

CYP3A5 genotype, 24-hour tacrolimus pharmacokinetic profiles.

RESULTS

∼80% of participants carried the CYP3A5*1 allele (CYP3A5 expressers). There were no significant differences in AUC_0-24 or C_min between CYP3A5 expressers and nonexpressers during administration of either IR-Tac or LCPT. With IR-Tac, tacrolimus C_max was 33% higher in CYP3A5 expressers compared with nonexpressers (P=0.04): With LCPT, this difference was 11% (P=0.4).

LIMITATIONS

This was primarily a pharmacogenetic study rather than an efficacy study; the follow-up period was too short to capture clinical outcomes.

CONCLUSIONS

Achieving therapeutic tacrolimus trough concentrations with IR-Tac in most African Americans results in significantly higher peak concentrations, potentially magnifying the risk for toxicity and adverse outcomes. This pharmacogenetic effect is attenuated by delayed tacrolimus absorption with LCPT.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov, with study number NCT01962922.