Efficacy and safety of conversion from twice-daily to once-daily tacrolimus in a large cohort of stable kidney transplant recipients

Efficacy of Prolonged-release Tacrolimus After Conversion From Immediate-release Tacrolimus in Kidney Transplantation: A Retrospective Analysis of Long-term Outcomes From the ADMIRAD Study

Prolonged-release tacrolimus (PRT) may offer improved outcomes after kidney transplantation compared with immediate-release tacrolimus (IRT). However, data on outcomes beyond 5-y posttransplantation are lacking.

Methods

A retrospective, noninterventional chart review study examined long-term graft survival in adult kidney transplant participants in the Adherence Measurement in Stable Renal Transplant Patients Following Conversion From Prograf to Advagraf (ADMIRAD) clinical trial at 4 Belgian sites. Patients were randomized to receive once-daily PRT or twice-daily IRT for 6 mo, followed by treatment as per real-world clinical practice. Data were collected retrospectively from randomization day until December 31, 2018. Primary endpoints included efficacy failure, defined as a composite endpoint of graft loss, biopsy-confirmed acute rejection, and graft dysfunction. Secondary endpoints included overall patient survival and course of kidney function.

Results

This analysis included 78.5% of patients from ADMIRAD (n = 108 PRT; n = 64 IRT). The Kaplan-Meier survival rate without efficacy failure from randomization to year 5 was 0.741 (95% confidence interval [CI]: 0.647, 0.813) for the PRT group (n = 80), and 0.667 (95% CI: 0.536, 0.768) for the IRT group (n = 42) and remained higher for PRT throughout 10 y follow-up (P = 0.041). The Kaplan-Meier estimate of overall survival from the time of last transplant was 0.981 (95% CI: 0.928, 0.995) and 0.880 (95% CI: 0.802, 0.928) at 5 and 10 y in the PRT group. Kidney function parameters and tacrolimus trough levels remained stable over the follow-up period.

Conclusions

Patients in the ADMIRAD study who received PRT for up to 10 y had improved long-term outcomes compared with patients receiving IRT, with a consistent effect on both graft and patient survival.

Evaluation of limited-sampling strategies to calculate AUC(0–24) and the role of CYP3A5 in Chilean pediatric kidney recipients using extended-release tacrolimus

Background: Kidney transplantation (KTx) requires immunosuppressive drugs such as Tacrolimus (TAC) which is mainly metabolized by CYP3A5. TAC is routinely monitored by trough levels (C0) although it has not shown to be a reliable marker. The area-under-curve (AUC) is a more realistic measure of drug exposure, but sampling is challenging in pediatric patients. Limited-sampling strategies (LSS) have been developed to estimate AUC. Herein, we aimed to determine AUC(0–24) and CYP3A5 genotype in Chilean pediatric kidney recipients using extended-release TAC, to evaluate different LSS-AUC(0–24) formulas and dose requirements.

Patients and methods: We analyzed pediatric kidney recipients using different extended-release TAC brands to determine their trapezoidal AUC(0–24) and CYP3A5 genotypes (SNP rs776746). Daily TAC dose (TAC-D mg/kg) and AUC(0–24) normalized by dose were compared between CYP3A5 expressors (*1/*1 and *1/*3) and non-expressors (*3/*3). We evaluated the single and combined time-points to identify the best LSS-AUC(0–24) model. We compared the performance of this model with two pediatric LSS-AUC(0–24) equations for clinical validation.

Results: Fifty-one pharmacokinetic profiles were obtained from kidney recipients (age 13.1 ± 2.9 years). When normalizing AUC(0–24) by TAC-D significant differences were found between CYP3A5 expressors and non-expressors (1701.9 vs. 2718.1 ng*h/mL/mg/kg, p < 0.05). C0 had a poor fit with AUC(0–24) (r2 = 0.5011). The model which included C0, C1 and C4, showed the best performance to predict LSS-AUC(0–24) (r2 = 0.8765) and yielded the lowest precision error (7.1% ± 6.4%) with the lowest fraction (9.8%) of deviated AUC(0–24), in comparison to other LSS equations.

Conclusion: Estimation of LSS-AUC(0–24) with 3 time-points is an advisable and clinically useful option for pediatric kidney recipients using extended-release TAC to provide better guidance of decisions if toxicity or drug inefficacy is suspected. The different CYP3A5 genotypes associated with variable dose requirements reinforce considering genotyping before KTx. Further multi-centric studies with admixed cohorts are needed to determine the short- and long-term clinical benefits.

Pharmacotherapeutic options for the prevention of kidney transplant rejection: the evidence to date

INTRODUCTION

Although early rejection episodes are successfully controlled, the problem of unrecognized production of de novo anti HLA antibodies and associated chronic rejection still persists.

AREAS COVERED

In addition to the standard induction and maintenance therapy, we present a couple of new drugs as induction (Alemtuzumab), CNI free protocol (Belatacept, Sirolimus, Everolimus), maintenance treatment in transplant patients with various type of malignancies (T cell targeted immunomodulators blocking the immune checkpoints CTLA-4, PD1/PDL1) and TMA (aHUS) -eculizimab, and IL6 receptor antagonists in antibody mediated rejection (AMR).

EXPERT OPINION

There are couple of issues still preventing improvement in kidney transplant long-term outcomes with current and anticipated future immunosuppression: patient more susceptible to infection and CNI nephrotoxicity in kidneys obtained from elderly donors, highly sensitized patients with limited chances to get appropriate kidney and a higher risk for late AMR. A lower rate of CMV/BK virus infections has been observed in everolimus treated patients. Belatacept use has been justified only in EBV seropositive kidney transplants due to the increased risk of PTLD. Eculizumab upon recurrence of aHUS is a sole cost-effective option. A new IL-6 blocking drug (clazakizumab/tocilizumab) is promising option for prevention/treatment of AMR. Clinical experience in tailoring immunosuppression for as long as possible graft and patient survival is inevitable.

Sustained Inhibition of Calcineurin Activity With a Melt-Dose Once-daily Tacrolimus Formulation in Renal Transplant Recipients

Tacrolimus (Tac) is the cornerstone calcineurin inhibitor in transplantation. Extended-release Meltdose formulation (Tac-LCP) offers better bioavailability compared with immediate-release formulation (Tac-IR). We postulated that the less fluctuating pharmacokinetic (PK) profile of Tac-LCP might maintain a sustained inhibition of calcineurin activity (CNA) between dose intervals. Higher concentrations (peak plasma concentration (C_max )) after Tac-IR may not result in a more potent CNA inhibition due to a capacity-limited effect. This study was aimed at evaluating the pharmacodynamic (PD)/PK profiles of Tac-IR compared with Tac-LCP. An open-label, prospective, nonrandomized, investigator-driven study was conducted. Twenty-five kidney transplant recipients receiving Tac-IR were switched to Tac-LCP. Before and 28 days after conversion, intensive CNA-PD and PK sampling were conducted using ultra-high-performance liquid chromatography-tandem accurate mass spectrometry. PD nonlinear mixed effects model was performed in Phoenix-WinNonlin. Statistically significant higher C_max (P < 0.001) after Tac-IR did not result in lower CNA as compared with after Tac-LCP (P = 0.860). Tac-LCP showed a statistically more maintained CNA inhibition between dose intervals (area under the effect-time curve from 0 to 24 hours (AUE_0-24h )) compared with Tac-IR, in which CNA returned to predose levels after 4 hours of drug intake (373.8 vs. 290.5 pmol RII·h/min·mg prot, Tac-LCP vs. Tac-IR; P = 0.039). No correlation was achieved between any PD and PK parameters in any formulations. Moreover, Tac concentration to elicit a 50% of the maximum response (half-maximal inhibitory concentration) was 9.24 ng/mL. The higher C_max after Tac-IR does not result in an additional CNA inhibition compared with Tac-LCP attributable to a capacity-limited effect. Tac-LCP may represent an improvement of the PD of Tac due to the more sustained CNA inhibition during dose intervals.

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.

Expected and Observed Glomerular Filtration Rates in Kidney Transplant Patients Converted to Once Daily Tacrolimus: 10 Years of Follow-up

The decline of allograft kidney function in the long term remains a significant issue in renal transplantation, with drug nephrotoxicity and cardiovascular complications as important risk factors. Our study aimed to evaluate the estimated glomerular filtration rate (eGFR) trend and metabolic cardiovascular risk factors over 10 years in a cohort of kidney transplant (KT) recipients converted from twice-daily (TD) tacrolimus (Tac) to once-daily (OD)-Tac. We enrolled 55 consecutive KT recipients who had been at the outpatient clinic between 2009 and 2011. Thirty-seven reached the 10-year follow-up. We compared the observed eGFR with the expected eGFR trend described in KT-recipients and monitored blood pressure and metabolic cardiovascular risk factors. The observed eGFR remained stable throughout the complete follow-up (P = .188). The observed decline of eGFR was significantly lower compared with the expected decline for KT patients (P < .001). The blood pressure was maintained within target values. The monitoring of plasma glucose levels demonstrated the stability of median values (P = .686), as well as cholesterol level (P = .250), high-density lipoprotein (HDL) cholesterol (P = .294), and triglycerides (P = .592) throughout the follow-up. The monitoring of tacrolimus plasma level demonstrated that median trough levels remained constant (median values 4.4-5.5 ng/mL) throughout the entire follow-up period (P = .149). We suggest that the reasonable control of metabolic risk factors for cardiovascular disease over long-term follow-up may significantly contribute to the preservation of eGFR compared with the decline expected in KT recipients.

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.

Tailored use of belatacept in adolescent kidney transplantation

Adolescent transplant recipients are at risk for nonadherence, development of de novo donor-specific antibody (dnDSA), and allograft loss. Belatacept, a selective T cell costimulatory blocker, is associated with reduced dnDSA, improved renal function, and prolonged allograft survival when compared to calcineurin inhibitor-based regimens in adults; however, its use in children is scant. Three adolescents were initiated on belatacept between August 2017 and September 2018 at the time of kidney transplantation. Selection criteria included age ≥ 14 and EBV IgG + serostatus. Intraoperative alemtuzumab and methylprednisolone were given as induction therapy. Tailored maintenance therapy included steroid-free belatacept and sirolimus for two patients. One patient was initially maintained steroid-free on belatacept and belimumab, an inhibitor of B cell activating factor to treat concurrent systemic lupus erythematous; steroids were added subsequently. Renal function, biopsy-proven rejection, dnDSA, allograft survival, infection, nonadherence, and proteinuria were monitored. Renal function was 86, 73, 52 mL/min/1.73 m² at 20, 20, and 8 months, respectively. There was 100% adherence to therapy and no development of dnDSA. All patients had treatable infections. One developed steroid-responsive acute cellular rejection. Belatacept-based regimens can be tailored for adolescent recipients with good short-term clinical outcomes.

Optimization of Electronically Monitored Non-Adherence in Highly Adherent Renal Transplant Recipients by Reducing the Dosing Frequency - A Prospective Single-Center Observational Study

BACKGROUND

Non-adherence (NA) after renal transplantation poses a major risk for allograft rejection, graft loss, and patient mortality. Yet, there is still ambiguity about its etiology and its possible relationships with patient-related factors. In order to prevent poor outcomes after transplantation, it is crucial to gain a more refined understanding of potential determinants, to identify patients at risk, and to intervene accordingly. The objective of this study was to assess potential risk factors of NA by prospectively applying electronic monitoring.

MATERIALS AND METHODS

This was a single-center prospective observational study. Prior to study initiation, sociodemographic, biomedical, and psychosocial variables (depression, health-related quality of life, self-efficacy, social support, attachment, experiences and attitudes towards immunosuppressive medication, emotional responses after organ transplantation, satisfaction with information about immunosuppressive medication, and perceptions and beliefs about medications) were assessed. Thereafter, immunosuppressive adherence behavior was measured prospectively via electronic monitoring (EM, VAICA©) during a 3-month period to receive the percentage frequency of Taking and Timing Adherence (±2h, ±30min) for each patient. Focus of this study was the phase of medication implementation.

RESULTS

A total of 78 patients participated in our study (mean age 55.28, 56% male). We found rates of 99.39% for Taking Adherence, 98.34% for Timing Adherence ±2h, and 93.34% for Timing Adherence ±30min, respectively.  Multiple regression analyses revealed that the type of medication could significantly predict Taking Adherence. Patients receiving Advagraf© (once daily) depicted better Taking Adherence than patients receiving Prograf© (twice daily) (p=0.04). No associations were found for Timing Adherence (±2h, ±30min). Sociodemographic, biomedical, or psychosocial variables were not found to be associated with adherence behavior.

DISCUSSION

In highly adherent populations, only a few factors can be altered to improve adherence. Changing the immunosuppressive regimen from twice-daily to once-daily could be an option for optimizing adherence. However, risk factors for NA could be different in a less adherent population.

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.

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.

A Multicenter, Prospective, Observational Study of Conversion from Twice-Daily Immediate-Release to Once-Daily Prolonged-Release Tacrolimus in Liver Transplant Recipients in France: The COBALT Study

Background

In adult liver transplant patients, the use of prolonged-release tacrolimus may have treatment adherence benefits over the immediate-release formulation. The aim of this study was to characterise real-world practice data on conversion of liver transplant recipients from immediate- to prolonged-release tacrolimus in France.

Material/Methods

A prospective, observational study (NCT02143479) was conducted in 18 transplant centers in France between June 2014 and March 2016. Liver transplant recipients (n=398) included patients who changed from immediate-release to prolonged-release tacrolimus within the first three months (early conversion group) (n=205) or between three and 12 months after transplantation (late conversion group) (n=184). Clinical data were collected at an initial baseline outpatient visit and six-month and 12-month follow-up visits. Endpoints included the dose conversion ratio from immediate-release to prolonged-release tacrolimus, number of and reasons for additional visits due to conversion, safety, and tolerability.

Results

Baseline clinical and demographic characteristics were similar between the two cohorts. The mean ±SD ratio of conversion of tacrolimus dose was 1.04±0.28; 1.01±0.28 (early) and 1.08±0.28 (late) (p=0.0247). The mean ±SD time from conversion to the first tacrolimus trough blood concentration was 30.8±42.8 days; 24.8±45.4 days (early) and 37.5±38.7 days (late). Only one patient required an additional visit due to conversion. Reasons for conversion included the physician’s preference (56.3%), center practice (38.6%), and the dosing frequency (36.0%). Conversion was associated with a low rate of graft rejection, and no new safety issues were reported.

Conclusions

Conversion of liver transplant recipients from immediate-release to prolonged-release tacrolimus within three to 12 months of transplantation was easy to manage and associated with favorable clinical outcomes and safety profiles.

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.

Efficacy and safety of prolonged-release versus immediate-release tacrolimus inde novoliver transplant recipients in South Korea: a randomized open-label phase 4 study (MAPLE)

Background

Prolonged-release tacrolimus is associated with better long-term graft and patient survival than the immediate-release formulation in liver transplant patients. However, no clinical data are available to assess the efficacy and safety of early conversion from twice-daily, immediate-release tacrolimus to once-daily, prolonged-release tacrolimus in de novo liver transplant recipients in Korea.

Methods

A 24-week, randomized, open-label study was conducted in 36 liver transplant recipients. All patients received immediate- release tacrolimus (0.1–0.2 mg/kg/day, divided into two doses) for 4 weeks after transplantation, at which time 50% of the patients were converted, at a ratio of 1 mg to 1 mg, to prolonged-release tacrolimus (once-daily). The primary efficacy endpoint was the incidence of biopsy-confirmed acute rejection (BCAR) from weeks 4 to 24 after transplantation (per-protocol set). Medication adherence, adverse event profiles, laboratory tests, vital signs, and physical changes were also recorded.

Results

BCAR frequency at 24 weeks was similar between the two treatment groups; two cases (mean±standard deviation, 0.14±0.53 cases) of BCAR were reported in one patient treated with prolonged-release tacrolimus (n=14), while no such cases were reported among patients treated with immediate-release tacrolimus (n=12). The tacrolimus blood concentration at weeks 12 and 24, medication adherence, and adverse event profiles were also similar between the formulations, with no unusual laboratory test results, vital signs, or physical changes reported.

Conclusions

Early conversion to a simplified, once-daily, prolonged-release tacrolimus regimen may be an effective treatment option for liver transplant recipients in Korea. Larger-scale studies are warranted to confirm non-inferiority to immediate-release tacrolimus formulation in de novo liver transplant recipients.

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.

Incidence of Donor-Specific Anti-HLA Antibodies in Non-HLA-Sensitized Patients Given Tacrolimus Once or Twice Daily During the First 2 Years After Kidney Transplant

OBJECTIVES

Antibody-mediated rejection is a main cause of long-term kidney allograft loss. Nonad-herence and tacrolimus intrapatient variability have been identified as risk factors for developing de novo donor-specific antibodies. Tacrolimus, given once daily, can improve adherence and reduce variabilities among patients. The aim of this retrospective observational study was to compare the incidences of donor-specific antibodies at 2 years posttransplant in de novo kidney transplant recipients given tacrolimus either once or twice daily.

MATERIALS AND METHODS

Non-HLA sensitized de novo kidney-transplant recipients given tacrolimus either once daily (n = 82) or twice daily (n = 168), combined with mycophenolic acid with or without steroids, were included in the study. All patients were screened for anti-HLA antibodies before transplant, at 6, 12, and 24 months posttransplant, and each time the patient presented with impaired kidney function.

RESULTS

The 2-year incidence of donor-specific antibodies was 2.8%. During the follow-up period, 6 patients (3.6%) receiving tacrolimus twice daily and one patient (1.2%) receiving tacrolimus once daily developed a donor-specific antibody (P = .43). The incidence of antibody-mediated rejection was 4.8% under tacrolimus once daily and 2.7% under tacrolimus twice daily (P = .5). Tacrolimus intrapatient variability was similar with both formulations and was not associated with development of donor-specific antibodies.

CONCLUSIONS

The use of tacrolimus-based immunosup-pression associated with mycophenolic acid was associated with a low risk of de novo donor-specific antibodies. After 2 years, the incidence of de novo donor-specific antibodies did not differ significantly between patients treated with tacrolimus once daily versus those treated with the twice-daily formulation.

High tacrolimus trough level variability is associated with rejections after heart transplant

Tacrolimus, the major immunosuppressant after heart transplant (HTx) therapy, is a narrow therapeutic index drug. Hence, achieving stable therapeutic steady state plasma concentrations is essential to ensure efficacy while avoiding toxicity. Whether high variability in steady state concentrations is associated with poor outcomes is unknown. We investigated the association between tacrolimus trough level variability during the first year post-HTx and outcomes during and beyond the first postoperative year. Overall, 72 patients were analyzed for mortality, of whom 65 and 61 were available for rejection analysis during and beyond the first year post-HTx, respectively. Patients were divided into high (median >28.8%) and low tacrolimus level variability (<28.8%) groups. Mean tacrolimus levels did not differ between the groups (12.7 ± 3.4 ng/mL vs 12.8 ± 2.4 ng/mL, P = .930). Patients in the high variability group exhibited higher long-term rejection rate (median total rejection score: 0.33 vs 0, P = .04) with no difference in rejection scores within the first year post-HTx. Multivariate analysis showed that high tacrolimus trough level variability was associated with >8-fold increased risk for any rejection beyond the first year post-HTx (P = .011). Mortality was associated only with cardiovascular complications (P = .018), with no effect of tacrolimus through level variability.

Immunosuppression Adherence in Stable Kidney Transplant Patients Converted From Immediate- to Prolonged-Release Tacrolimus in Clinical Practice: A Norwegian Study

Background

This study investigated medication adherence in kidney transplant patients (KTPs) converted from immediate-release tacrolimus (IR-T) to prolonged-release tacrolimus (PR-T)-based immunosuppression in routine practice.

Methods

Noninterventional, observational, multicenter study in Norway. Included adult KTPs with stable graft function, converted from IR-T (baseline) to PR-T (1 mg:1 mg) in routine practice. Data were collected at baseline, and months 1, 3, 6, and 12 postconversion. Primary endpoint: adherence using the Basel Assessment of Adherence to Immunosuppressive Medication Scale. Secondary assessments: tacrolimus dose and trough levels (target, 3-7 ng/mL), clinical laboratory parameters (eg, estimated glomerular filtration rate [Modified Diet in Renal Disease]), and adverse events.

Results

Ninety-one KTPs (mean ± SD age 47.7 ± 14.3 years) were analyzed. Mean ± SD change in PR-T dose from baseline (4.4 ± 2.4 mg/d) to month 12 was −0.1 ± 0.9 mg/d; mean tacrolimus trough levels remained within target. Overall medication adherence increased from 45.6% at baseline to 58.1% at month 1, but was similar to baseline thereafter; taking and timing adherence followed a similar pattern. Odds ratio (OR) for adherence at month 1 (but not at other time points) was greater versus baseline for overall (OR, 1.71; P = 0.0205), taking (OR, 3.38; P = 0.0004), and timing (OR, 1.77, P = 0.0252) dimensions. Mean ± SD Basel Assessment of Adherence to Immunosuppressive Medication Scale visual analogue scale score at baseline was 96.4 ± 5.5%, and increased postconversion. Estimated glomerular filtration rate remained stable (month 12, 61.6 ± 17.7 mL/min per 1.73 m²), as did other laboratory parameters. Two (2.2%) patients had adverse events considered probably/possibly treatment-related.

Conclusions

There was disparity between high, patient-perceived and low, actual adherence. Converting stable KTPs from IR-T to PR-T in routine practice did not impact long-term adherence to immunosuppression; renal function remained stable.

Two Decades of Tacrolimus in Renal Transplant: Basic Science and Clinical Evidences

Tacrolimus, a calcineurin inhibitor, has been the cornerstone of immunosuppressive regimens in renal transplant over 2 decades. This has significantly improved the outcomes of renal transplant, including reduction of acute rejection episodes, improvement of renal function and graft survival, and reduction of some of the adverse effects associated with cyclosporine. However, use of tacrolimus is associated with a number of undesirable effects, such as nephrotoxicity, posttransplant diabetes mellitus, neurotoxicity, and cosmetic and electrolyte disturbances. To alleviate these effects, several strategies have been adopted to minimize or eliminate tacrolimus from maintenance regimens of immunosuppression, with some success. This review focuses on advancements in the understanding of the basic science related to tacrolimus and the clinical evidences that have examined the efficacy and safety of tacrolimus in renal transplant over the past 2 decades and highlights the future directions.

Conversion From Twice-Daily to Once-Daily Tacrolimus in Stable Kidney Graft Recipients

INTRODUCTION

Immunosuppression has a pivotal role in kidney transplantation. The new prolonged-release formulation of tacrolimus was developed to provide a more convenient once-daily dosing to improve patient adherence.

METHODS

We selected 60 stable kidney transplant recipients who underwent tacrolimus conversion in our unit. Conversion was made on a 1 mg:1 mg basis in 66.7% of patients (n = 40) and on a 1 mg:1.1 mg basis in the remaining 33.3% (n = 20). Clinical and analytical data at conversion and postconversion was analyzed retrospectively to evaluate the efficacy and safety of conversion from tacrolimus twice-daily to once-daily formulation.

RESULTS

A significant reduction in tacrolimus blood levels requiring an increase in tacrolimus daily dose was observed postconversion. Postconversion tacrolimus blood level reduction >25% was significantly higher in the conversion group 1 mg:1 mg basis (P = .004). In patients converted 1 mg:1 mg, female sex and higher tacrolimus level at conversion were significant risk factors for a reduction >25% in tacrolimus blood levels after conversion. No significant change was detected between mean glomerular filtration rate at conversion (57 mL/min) and at 3, 6, and 9 months postconversion.

CONCLUSIONS

Once-daily tacrolimus at similar doses to the twice-daily formulation is an efficient and safe treatment option. Conversion made on 1 mg:1.1 mg basis seems advantageous at least in some patients.

Pharmacokinetics of prolonged-release tacrolimus and implications for use in solid organ transplant recipients

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.

Review of the Clinical and Economic Burden of Antibody-Mediated Rejection in Renal Transplant Recipients

Antibody-mediated rejection (AbMR) is a leading cause of late graft loss in kidney transplant recipients, accounting for up to 60% of late graft failures. AbMR manifests as two distinct phenotypes: the first occurs in the immediate post-transplant period in sensitized patients; the second occurs in the late post-transplant period and has been associated with non-adherence to immunosuppression. The present review summarizes the current treatment options for AbMR, its clinical and economic burden, and approaches for reducing the risk of AbMR. While AbMR is typically refractory to treatment with corticosteroids, there are numerous other approaches focused on removal, inhibition or neutralization of donor-specific antibodies, or inhibition of complement-mediated allograft damage. AbMR treatment is generally expensive with one US study reporting costs of USD 49,000-155,000 per episode. However, leaving AbMR untreated puts patients at high risk of capillaritis, microangiopathy, necrosis and graft failure, which may ultimately result in much greater costs associated with a return to dialysis. Given the barriers to treatment, which include the high cost and the fact that pharmacologic treatments are currently used off-label, prevention of AbMR is important, with improvement in patient adherence to immunosuppression a key strategic approach that may be worthy of further evaluation.

FUNDING

Astellas Pharma EMEA Limited.

The role of CYP3A5 polymorphism and dose adjustments following conversion of twice-daily to once-daily tacrolimus in renal transplant recipients

Background

Tacrolimus is available as twice-daily Prograf® (Tac-BID) and the once-daily formulation, Advagraf® (Tac-OD). Although therapeutically equivalent, some transplant recipients require dose adjustments to achieve similar tacrolimus trough concentrations [Tac C₀] after conversion between formulations. Tacrolimus is primarily metabolized by cytochrome P450 3A5 (CYP3A5). We sought to determine whether genetic polymorphisms in the CYP3A5 enzyme; CYP3A5 *1/*1 and CYP3A5 *1/*3 (expressers) compared to CYP3A5 *3/*3 (non-expressers) could account for discrepancies in dose requirements following conversion from Tac-BID to Tac-OD.

Methods

A cohort of 60 renal transplant recipients (RTR) from our larger conversion study of 496 patients underwent additional testing for CY3A5 genetic polymorphisms. Analysis included demographics, tac dosing and [Tac C₀] pre- and post-conversion and dosing changes relative to CYP3A5 genotypes. CYP3A5 genetic polymorphisms were identified through analysis of genomic DNA.

Results

Conversion from tac bid to tac OD in this cohort required a mean (SD) dose increase from 3.1 (1.0) mg/day to 3.8 (1.3) mg/day (p = 0.007), to achieve similar [Tac C₀]. The *1/*3 expresser group required a greater percentage dose adjustment (56.7 %) in converting from Tac-BID to Tac-OD as compared to the *3/*3 non-expresser group (26.6 %). Similar findings were observed with the both expresser groups combined (*1/*1 &*1/*3). The expressers were significantly more highly represented in the East Asian cohort.

Conclusions

The CYP3A5 expresser polymorphism necessitates an increase in dosing upon conversion from Tac-BID to Tac-OD, with the expresser genotypes contributing significantly to this finding. Given the variability in frequency of CYP3A5 genotypes in various ethnic groups, future studies should account for both isoenzyme polymorphism and ethnicity in optimizing dosing requirements.

Trial registration

Clinical trials.gov identifier: NCT01884480

Patient survey to identify reasons for non-adherence and elicitation of quality of life concepts associated with immunosuppressant therapy in kidney transplant recipients

BACKGROUND

Renal transplantation (RT) is considered the treatment of choice for end-stage renal disease compared to dialysis, offering better health-related quality of life (HRQoL) and higher survival rates. However, immunosuppressants are essential for the long-term survival of kidney grafts and patients' non-adherence to their medication leads to poor outcomes. Immunosuppressants can also significantly alter patients' HRQoL because of their side effects and the complex chronic medication regimen they represent.

PURPOSE

To elicit key concepts related to adherence to immunosuppressant therapy (IT) and reasons for non-adherence in terms of patient reported outcomes, side effects, and the impact of the medication on HRQoL in RT population, including patient preference of once daily over twice-daily immunosuppressive regimen. Results were used to develop an IT-specific conceptual framework and provide suggestions for improving patients' adherence to IT.

MATERIALS AND METHODS

Interviews were conducted with three clinical experts to determine key concepts related to RT and immunosuppressants. Thirty-seven participants in four focus groups were asked to cite important concepts related to adherence and impact of IT on HRQoL and to rate them. Qualitative analysis was conducted to code participants' responses.

RESULTS

Non-adherence among participants where admitted was unintentional. The reason for this included forgetfulness, interference with lifestyle, being asleep at the time the medication should be taken, change in routine, and impact of side effects. Overall, participants reported that the evening dose was more problematic to remember and that the exclusion of this dose could make them more adherent. Participants also reported that IT impacted on their HRQoL in a number of ways including: placing restrictions on their lifestyle, causing anxiety, or impairing their ability to work.

CONCLUSION

This study provides qualitative evidence about the barriers to IT adherence and the components of HRQoL that are important from the perspective of RT patients. The developed conceptual framework of IT-HRQoL in RT transplants, including social, psychological, and work life domains, can be used to inform the development of a new IT-specific measure of HRQoL in RT patients for use in head-to-head clinical trials or observational studies. Despite limitations associated with the number and the age range of patients recruited, this study suggests that a change in the regimen from twice-daily to once daily among other measures could improve their adherence to IT and their HRQoL by placing less restrictions on their lifestyles.

Conversion from twice-daily to once-daily tacrolimus does not reduce intrapatient variability in tacrolimus exposure

BACKGROUND

Intrapatient variability (IPV) in tacrolimus exposure is associated with renal allograft failure. The aim of this study was to investigate whether conversion from the twice-daily tacrolimus formulation (Tac-TD) to a once-daily formulation (Tac-OD) leads to a lower IPV in tacrolimus exposure.

METHODS

Two hundred forty-seven stable renal transplant recipients were converted from Tac-TD to Tac-OD (Advagraf) on a 1:1-mg total daily dose basis. After conversion, patients were followed for 12 months and tacrolimus predose whole-blood concentrations (C0), serum creatinine, estimated glomerular filtration rate, and proteinuria were measured. These parameters were compared with those collected at all outpatient visits in the 12-month period (±3 months) before conversion (Tac-TD period). The IPV was calculated based on the dose-adjusted tacrolimus C0.

RESULTS

The Tac-OD formulation provided an excellent graft survival (100%), a low acute rejection rate (0.8%), and good tolerability. Renal function remained stable: estimated glomerular filtration rate 48 (16-90) versus 46 (12-90) mL/min (P = 0.15) before and after conversion, respectively. After conversion to Tac-OD, mean C0 was significantly lower, decreasing from 5.7 ± 1.5 to 5.0 ± 1.5 ng/mL, corresponding to a 12% reduction (P < 0.01). Both drugs had similar IPVs (Tac-TD: 17.3% ± 1.6% versus Tac-OD: 16.4% ± 1.6%, P = 0.31).

CONCLUSIONS

Although conversion from Tac-TD to Tac-OD significantly reduces tacrolimus exposure as measured by C0 and seems safe, it does not reduce IPV in tacrolimus exposure.

A single center, open-label, randomized pilot study to evaluate the safety and efficacy of tacrolimus modified release, Advagraf, versus tacrolimus twice daily, Prograf, in stable renal recipients (single)

BACKGROUND

Compliance with immunosuppressive regimens may affect clinical outcomes in renal transplant recipients. The aim of this study was to assess the safety and efficacy of standard-dose tacrolimus modified-release (TAC-MR) once daily versus tacrolimus (TAC) twice daily in stable renal transplant recipients.

METHODS

Ninety-nine stable renal transplant recipients were randomized to receive standard-dose tacrolimus twice daily or standard-dose modified-release tacrolimus once daily on a 1:1 (mg:mg) basis. The primary end point was the incidence of adverse events (AEs) in both groups. Secondary end points included biopsy-proven acute rejection, graft survival, patient survival, clinical indicators, and change in score of questionnaire.

RESULTS

The incidence of AEs was not different between the TAC and TAC-MR groups (56.0% vs 53.1%, P > .05). There were no significant differences in mean calculated glomerular filtration rate, blood pressure, glycosylated hemoglobulin (HbA1c), blood concentration of tacrolimus, and drug compliance. The scores of all items in the 36-item short form health survey (SF-36) were not different between groups, except for vitality. With respect to the subject questionnaire, there was no difference in question scores between the two treatment groups.

CONCLUSION

A regimen of TAC-MR once daily can be considered as an effective and safe alternative formulation of tacrolimus in stable renal transplant patients.

Advagraf(®) , a once-daily prolonged release tacrolimus formulation, in kidney transplantation: literature review and guidelines from a panel of experts

The efficacy and safety of tacrolimus twice-a-day (BID) and once-a-day (QD) formulations are similar. However, the available information regarding the initiation and management of tacrolimus QD is sparse and practical information is lacking. A panel of French experts extensively reviewed the available literature on tacrolimus pharmacokinetics, clinical efficacy, and safety in kidney transplantation and, based on their own day-to-day experience, provided the practitioners with practical guidelines for the daily use and management of tacrolimus QD in de novo initiation or early conversion.

Medium-Term Renal Function in a Large Cohort of Stable Kidney Transplant Recipients Converted From Twice-Daily to Once-Daily Tacrolimus

BACKGROUND

There is some evidence pointing toward better renal function in kidney transplant recipients (KTR) treated with once-daily tacrolimus (QD-TAC) vs. twice-daily tacrolimus (BID-TAC).

METHODS

This is an extension study of a 1-year, single arm prospective study of stable KTR who were converted from BID-TAC to QD-TAC (4.9 ± 4.0 years after transplantation) in Spanish routine clinical practice. Patient and graft survival, renal function, acute rejection episodes, and other analytic parameters were assessed at 24 and 36 months after conversion.

RESULTS

A total of 1798 KTR were included in the extension study. Tacrolimus doses at 36 months were significantly lower compared to those at time of conversion (-0.2 mg/day; P = 0.023). Blood levels were lower than baseline during all the study (P < 0.001). Graft and patient survival at 3 years after conversion were 93.9% and 95.1%, respectively. Compared with baseline, the mean estimated glomerular filtration rate (eGFR) remained very stable at all timepoints (56.7 ± 19.8 vs 58.1 ± 24.6 mL/min per 1.73 m(2) at month 36; P = 0.623). Even when patients reinitiating dialysis were counted as eGFR = 0, the mean eGFR was very stable. In fact, a small but significant increase was observed at 36 months versus baseline (+0.1 mL/min per 1.73 m(2); P = 0.025). An increase in proteinuria was observed at 36 months versus baseline (+0.11 g/24 h; P < 0.001). Acute rejection rates were low during the study.

CONCLUSIONS

Conversion from BID-TAC to QD-TAC in a large cohort of stable KTR was safe and associated with a very stable renal function after 3 years. Comparative studies are warranted to assess the feasibility of such conversion.

Evaluating the economic implications of non-adherence and antibody-mediated rejection in renal transplant recipients: the role of once-daily tacrolimus in the UK

BACKGROUND AND AIMS

While short-term kidney graft survival has gradually improved over time, improvements in long-term graft survival have been more modest. One key clinical factor limiting improved longer-term outcomes is antibody-mediated rejection (AbMR), the incidence of which appears to be higher in patients who are non-adherent to immunosuppressants. Recent data show that adherence can be improved by reducing pill burden. The aim of the present study was to model the incidence and economic consequences of graft loss and AbMR in patients taking once- vs twice-daily tacrolimus in the UK.

METHODS

A combined decision tree and Markov model was developed to estimate the incidence of graft failure, AbMR and mortality in renal transplant recipients taking once- vs twice-daily tacrolimus. Underlying rates of graft failure and mortality were derived from UK-specific sources. Proportions of patients adherent to once- vs twice-daily tacrolimus were taken from a recent randomized clinical trial and relative risks of graft failure and AbMR were taken from a prospective, multi-center analysis of 315 patients. Cost data were taken from the British National Formulary and National Health Service reference costs and reported in 2014 pounds sterling.

RESULTS

Modeling results showed that improved adherence would be associated with reduced incidence of AbMR and graft failure in renal transplant recipients. Based on improvements in adherence resulting from switching from twice-daily to once-daily tacrolimus, the modeling analysis projected cost savings of GBP 4862 per patient over 5 years with Advagraf relative to Prograf, on absolute costs of GBP 40,974 and GBP 45,836, respectively.

CONCLUSIONS

Using Advagraf in place of Prograf in renal transplant recipients was predicted to be associated with lower pharmacy, dialysis and AbMR treatment costs, with the reduction in AbMR and dialysis costs being driven by improved adherence to the Advagraf regimen and consequent reductions in graft failure and onset of AbMR.

Safety and efficacy of once-daily modified-release tacrolimus in kidney transplant recipients: interim analysis of multicenter postmarketing surveillance in Japan

INTRODUCTION

Modified-release formulation of tacrolimus (TAC-MR) has been developed with the intent of improving patient adherence and quality of life. A number of studies have indicated that the efficacy and safety of once-daily TAC-MR were comparable with those of the original formulation, twice-daily TAC. However, its dosage, trough level, safety, and efficacy in the multicenter clinical experience of Japanese kidney transplant recipients have not been reported.

METHODS

This post-marketing surveillance designed as an open-label, prospective, noncomparative, noninterventional observational study was performed. The 256 patients were enrolled for de novo transplantation, and the 106 patients were enrolled for conversion to TAC-MR from 52 medical institutions in Japan. The follow-up period in de novo transplantation was 5 years, but here we report the results of the 24-week interim analysis. The observation period in conversion was 24 weeks.

RESULTS

Regarding de novo transplantation, the median daily TAC-MR dose was 0.150 mg/kg/d at the initial administration and the median TAC trough level was 12.1 ng/mL at 3 days. The common adverse drug reactions were infections, renal disorders, and glucose tolerance disorders at incidence rates of 23.6%, 6.8%, and 5.6%, respectively. Both patient and graft survival rates at 24 weeks were 98.2% and the rejection rate was 16.1%. Regarding conversion to TAC-MR, the median conventional TAC dose before conversion was 3.2 mg/d, and the median TAC-MR dose at the converted day was 3.2 mg/d. The median TAC trough level was 5.4 ng/mL before conversion, and it was 5.2 ng/mL after conversion. The most common adverse drug reactions were infections at an incidence rate of 4.9%. There was 1 graft loss and death, and there was 1 episode of rejection.

CONCLUSION

This interim analysis shows that a TAC-MR-based immunosuppressive regimen is safe and effective as used in Japanese clinical practice.

A randomized cross-over comparison of short-term exposure of once-daily extended release tacrolimus and twice-daily tacrolimus on renal function in healthy volunteers

Calcineurin inhibitor nephrotoxicity remains an issue for transplant recipients. The pharmacokinetic profile (PK) of the once-daily tacrolimus extended release (Tac-ER) includes equivalent exposure [AUC(0-24 h) ] but lower Cmax versus twice-daily tacrolimus immediate release (Tac-IR). We hypothesized that the unique PK profiles would result in pharmacodynamic differences in renal function. Nineteen healthy male subjects were allocated to once-daily Tac-ER and twice-daily Tac-IR in a prospective, randomized, two period, cross-over study. Tacrolimus was titrated to achieve trough levels of 8-12 ng/ml. Twenty four hours ERPF and GFR estimated by para-aminohippurate and sinistrin clearance were performed at baseline and at the end of each 10-day dosing period. Mean Tac C0 was 11.0 ± 2.2 and 11.3 ± 1.8 ng/ml for Tac-ER and Tac-IR, respectively. The mean Effective 24 h renal plasma flow (ERPF) was significantly higher with Tac-ER compared with Tac-IR (658 ± 127 vs. 610 ± 93 ml/min/1.73 m(2) , P = 0.046). There was a trend to a greater mean GFR over 24 h for Tac-ER at 114.5 ± 13.6 ml/min/1.73 m(2) compared with 108.9 ± 9.7 ml/min/1.73 m(2) for Tac-IR, P = 0.116. Under controlled physiological conditions, ERPF was significantly improved with Tac-ER compared with Tac-IR, likely owing to the differing PKs of these tacrolimus preparations (ClinicalTrials.gov Identifier: NCT01681134).

Safety and efficacy of conversion from twice-daily tacrolimus to once-daily tacrolimus one month after transplantation: randomized controlled trial in adult renal transplantation

PURPOSE

The purpose of this study was to compare once-daily tacrolimus with twice-daily tacrolimus in terms of safety, efficacy, and patient satisfaction.

MATERIALS AND METHODS

This prospective, randomized, open-label, multicenter study was conducted at three institutes. Patients in the investigational group were converted from tacrolimus twice daily to the same dose of extended-release tacrolimus once daily at 1 month post-transplantation, while patients in the control group were maintained on tacrolimus twice daily. The efficacies, safeties, and patient satisfaction for the two drugs at 6 months post-transplantation were compared.

RESULTS

Sixty patients were enrolled and randomized to the investigational group (28 of 29 patients completed the study) or the control group (26 of 31 patients completed the study). At 6 months post-transplantation, composite efficacy failure rates including the incidences of biopsy-confirmed acute rejection in the investigational and control groups were 0% and 10.7%, respectively; patient survival was 100% in each group. No difference in estimated glomerular filtration rate values were observed at 6 months post-transplantation (p=0.97). The safety and satisfaction profile (immunosuppressant therapy barrier scale) of once-daily tacrolimus was comparable with that of twice-daily tacrolimus (p=0.35).

CONCLUSION

Conversion from twice-daily tacrolimus to once-daily tacrolimus one month after transplantation is safe and effective.

Conversion from Prograf to Advagraf in stable kidney transplant recipients: better renal function after 3-year follow-up

BACKGROUND

The complexity of treatment after solid organ transplantation has been related to non-adherence to therapy prescriptions and to reduced graft survival. The aim of this study was to evaluate the middle-term effects of the conversion from Prograf (TAC), to extended-release tacrolimus (Advagraf) (ADV) in stable kidney transplant recipients.

METHODS

Conversion from TAC to ADV (dose, 1:1 mg/mg) was planned in 78 kidney transplant patients with stable renal function 71±48 months after renal transplantation. Before conversion, 1 week after conversion, and every 6 months up to 3 years, patients were evaluated clinically and by means of the usual blood chemistry and pharmacologic parameters.

RESULTS

Twenty patients (26%) refused to change their pre-existing immunosuppressive therapy; therefore, 58 patients entered the study and 45 (77%) completed the 3-year follow-up. Patient survival was 98% and allograft survival was 96%. Significant reduction in serum creatinine levels and increased glomerular filtration rate were observed after conversion (3-year creatinine: before TAC 1.67±0.47 mg/dL vs after ADV 1.47±0.62 mg/dL, P<.001; glomerular filtration rate, MDRD abbreviated: before TAC 49±15 mL/min vs after ADV 59±24 mL/min, P<.001). The daily dose and C0 blood levels of tacrolimus were stable before and after conversion (dose before vs 3 years after conversion: TAC 3.79±1.81 mg/day vs ADV 3.54±1.86 mg/day, P=ns; C0 tacrolimus blood levels, before vs 3 years after conversion: TAC 6.03±1.75 ng/mL vs ADV: 5.58±1.38 ng/mL, P = NS). One patient in the ADV group had an episode of acute rejection (2%).

CONCLUSIONS

Our data support the safety and efficacy of converting from Prograf to Advagraf in stable kidney transplant patients in the middle term. We suggest that the observed improvement in renal function after conversion to ADV is related to the reduction of the 24-hour tacrolimus area under the curve exposure.

Pharmacokinetic and CYP3A5 pharmacogenetic differences between once- and twice-daily tacrolimus from the first dosing day to 1 year after renal transplantation

Aim & patients & methods: This study investigated 24-h pharmacokinetic and CYP3A5 pharmacogenetic differences between once-daily tacrolimus (Tac-q.d.) versus twice-daily tacrolimus (Tac-b.i.d.) pretransplantation and at 1 month and 1 year post-transplantaion. Results: The dose-adjusted trough level (Cmin) and area under the blood concentration–time curve from 0 to 24 h (AUC0–24) increased twofold within 1 year post-transplantation with both formulations and the two genotypes. Good correlations were observed between the AUC0–24 and Cmin for both formulations. However, the dose-adjusted Cmin, but not dose-adjusted AUC0–24, was approximately 30% lower for Tac-q.d. than for Tac-b.i.d. Although the dose-adjusted Cmin was lower for Tac-q.d. than for Tac-b.i.d. in both genotypes, the dose-adjusted AUC0–24 was approximately 25% lower for Tac-q.d. than for Tac-b.i.d. in CYP3A5 expressers, but not in nonexpressers during the study period. Conclusion: These results suggested that the approximately 30% lower Cmin for Tac-q.d. than for Tac-b.i.d. may have achieved the same AUC0–24 with both formulations and may be associated with CYP3A5 pharmacogenomic differences, especially in CYP3A5 expressers, between Tac-b.i.d. and Tac-q.d.

Original submitted 3 May 2013; Revision submitted 11 June 2014

A UK analysis of the cost of switching renal transplant patients from an immediate-release to a prolonged-release formulation of tacrolimus based on differences in trough concentration variability

BACKGROUND AND AIMS

Randomized controlled trials have shown that a once-daily prolonged-release (PR) tacrolimus formulation (PR tacrolimus; Advagraf * ), is non-inferior to a twice-daily immediate-release (IR) tacrolimus formulation (IR tacrolimus; Prograf † ) in terms of biopsy-proven acute rejection, graft failure and mortality in renal transplant recipients. However, relative to IR tacrolimus, PR tacrolimus exhibits reduced tacrolimus trough concentration variability, which has been associated with reduced graft failure. Based on these data, the present study evaluated the cost of switching UK renal transplant patients from IR tacrolimus to PR tacrolimus.

METHODS

UK-specific data on acute rejection, graft failure, and mortality were used to construct a budget impact model to assess the costs of switching from IR tacrolimus to PR tacrolimus on a 1:1 mg:mg basis. The model assumed that 3.1% of patients on PR tacrolimus had high tacrolimus trough concentration variability compared with 17.4% on IR tacrolimus, based on a study comparing PR tacrolimus and IR tacrolimus pharmacokinetics. A relative graft failure risk of 2.38 was applied to high variability patients based on data from a tacrolimus variability study in which 10/148 patients with low variability experienced graft failure, compared with 24/149 in the high variability group. Cost data were taken from the British National Formulary and 2012-2013 NHS tariff information.

RESULTS

The mean per-patient cost (including tacrolimus, concomitant immunosuppressive medications, dialysis after graft failure, and treatment for acute rejection) was GBP 26,941 (standard deviation [SD] = GBP 2765) with PR tacrolimus vs GBP 30,356 (SD = GBP 3085) for IR tacrolimus over a 5-year period, corresponding to a saving of GBP 3415 (SD = GBP 516) per patient or GBP 341,500 in a hypothetical 100-patient transplant center. Cost savings were driven primarily by lower dialysis costs resulting from the lower proportion of PR tacrolimus patients with high tacrolimus trough concentration variability (leading to lower graft failure risk).

LIMITATIONS

The main limitation of the study was the use of heterogeneous data sources to capture the effect of within-patient variability on graft failure. The most important difference between the studies was the definition of the threshold between low and high within-patient variability. This was explored in sensitivity analyses in which the inter-arm difference in the inter-arm proportions of patients with high and low variability was abolished.

CONCLUSIONS

Converting UK renal transplant recipients from IR tacrolimus to PR tacrolimus was associated with lower pharmacy and dialysis costs.

A prospective cohort conversion study of twice-daily to once-daily extended-release tacrolimus: role of ethnicity

Background

Tacrolimus is a widely used calcineurin inhibitor in kidney transplantation. It is available as twice-daily Prograf® (Tac-BID) and once-daily Advagraf® (Tac-OD). Although therapeutically equivalent, some patients require dose adjustments to achieve similar trough concentrations [C₀] after conversion. Tacrolimus exposure is affected by ethnicity in the de novo setting but the role of ethnicity in determining dose requirements and adjustments after conversion is unknown.

Methods

In this study, 496 renal transplant recipients (RTRs) were prospectively converted from Tac-BID to Tac-OD, with dose adjustments targeted to achieve similar [C₀] at 12 months post-conversion. Renal function, acute rejection and Tac dose adjustments by ethnicity were analyzed.

Results

There were similar numbers of recipients from living and deceased donors. The mean transplant duration was 7 years. Of the RTRs, 60% were Caucasian and 40% were identified as belonging to an ethnic minority. There was no change in estimated renal function (eGFR) post-conversion to Tac-OD. At 12 months, 35/488 (7%) RTRs were receiving a reduced dose, 101/488 (21%) required a dose increase of which 77 (16%) were receiving at least a 30% increase in dose over baseline. The percentage of those in ethnic groups requiring a dose increase of >30% varied from 8.0% for South Asians to 27.5% for East Asians (P = 0.03), despite East Asians having a similar baseline dose of Tac-BID (3.59 mg/day) compared to the entire cohort (3.53 mg/day).

Conclusions

Ethnicity may play an important role in dosing requirements when converting from Tac-BID to Tac-OD, unrelated to baseline dose. Further investigation is required to determine the reasons for ethnic variability when patients are converted between tacrolimus preparations.