Conversion of stable liver transplant recipients from a twice-daily Prograf-based regimen to a once-daily modified release tacrolimus-based regimen

Renal Function, Adherence and Quality of Life Improvement After Conversion From Immediate to Prolonged-Release Tacrolimus in Liver Transplantation: Prospective Ten-Year Follow-Up Study

Immunosuppression non-adherence is a major cause of graft failure after liver transplantation. The aim of this study was to evaluate practice surrounding conversion from immediate-release to prolonged-release Tacrolimus formulation and to assess patient adherence and quality of life (QoL). One hundred and seven adult liver transplant recipients, receiving immediate-release Tacrolimus for a minimum of 6 months, were converted to prolonged-release formulation, based on a dose ratio of one (1:1). The median follow-up was 120 [IQR, 120-123] months. Tacrolimus dosage and blood level, liver and renal function, lipid and glucose profiles were recorded. In addition, questionnaires were submitted to evaluate adherence and QoL following conversion. No rejection was recorded. The median serum Tacrolimus blood level decreased over 1 month (5.80, [IQR, 2.0-10.8] vs. 3.8 [IQR, 1.4-8.7]; p < 0.0005). Significant improvement in renal function was noted (median GFR was 81.7 [IQR, 43.4-128.6] vs. 73.9 [IQR, 27.1-130.2]; p = 0.0002). At the end of the follow-up, conversion resulted in an overall decrease in non-adherence of 53.3% (p = 0.0001) and an improvement in QoL was reported by 76.2% of patients. Thus, 1:1 conversion from immediate to prolonged-release Tacrolimus is safe, feasible and efficient, avoiding under-therapeutic and toxic peak concentrations, improving renal function, adherence to immunosuppression and overall patient QoL.

Tacrolimus 4-hour monitoring in liver transplant patients is non-inferior to trough monitoring: The randomized controlled FK04 trial

BACKGROUND

After liver transplantation (LT), tacrolimus and ciclosporin treatment can lead to, partially concentration-dependent, chronic kidney disease. Monitoring ciclosporin with two-hour levels reduced overexposure and led to better renal function than trough-monitoring (C0). For tacrolimus, a 4-hour level (C4) can give a reasonable approximation of total drug exposure. We evaluated whether monitoring tacrolimus in stable patients after LT by C4 was superior to C0 regarding renal function, rejection and metabolic parameters.

METHODS

This open label randomized controlled trial compared C4 monitoring of tacrolimus BID (Prograft) to trough (C0) monitoring in stable LT recipients. The target range for C4 of 7.8-16 ng/ml was calculated to be comparable with target C0 of 4-8 ng/ml. Primary endpoint was the effect on renal function and secondary endpoints were the occurrence of treated biopsy-proven acute rejection, blood pressure and metabolic parameters, during 3 months of follow-up.

RESULTS

Fifty patients were randomized to C0 (n = 25) or C4 (n = 25) monitoring. There was no difference in renal function between the C0 and the C4 group (p = .98 and p = .13 for CG and MDRD at 3 months). Also, the amount of proteinuria was similar (p = .59). None of the patients suffered from graft loss or was treated for rejection. Metabolic parameters did not differ between the two groups.

CONCLUSION

Tacrolimus 4-hour monitoring in stable LT patients is not superior to trough monitoring, regarding the effect on renal function, but is safe for use to facilitate tacrolimus monitoring in an afternoon outpatient clinic.

Efficacy and Safety Evaluation After Conversion From Twice-Daily to Once-Daily Tacrolimus in Stable Liver Transplant Recipients: A Phase 4, Open-Label, Single-Center Study

BACKGROUND

Simplifying immunosuppressive therapy after liver transplant may improve patient compliance, thereby preventing acute rejection and graft loss. This phase 4, open-label, single-center study was conducted to evaluate the efficacy and safety of twice-daily to once-daily tacrolimus conversion in stable liver transplant recipients.

METHODS

Between May 2017 and January 2019, twice-daily tacrolimus was converted to once-daily tacrolimus in 101 stable recipients at least 12 months post-liver transplant in Asan Medical Center. The doses of both drugs was converted to 1:1, and the target trough level was 5 to 10 ng/mL. We prospectively analyzed graft function, drug compliance, and adverse reactions after switching regimen for 24 weeks.

RESULTS

There was no acute rejection confirmed histologically within 24 weeks, which was the primary endpoint, and there was no chronic rejection, fatal deterioration of liver function, or death in any patient during this period. After conversion, the trough level of tacrolimus decreased, and the mean ± standard deviation differences between the trough level and baseline level were 1.46 (±2.41) ng/mL, 0.43 (±2.08) ng/mL, and 0.07 (±2.73) ng/mL at 3, 12, and 24 weeks after conversion, respectively. Despite transient fluctuations of the trough level, there was no evidence of rejection or graft dysfunction. There were 37 adverse reactions after conversion; most of them were mild, and thrombocytopenia developed in 1 patient as an adverse drug response. Drug compliance improved after conversion according to questionnaire responses.

CONCLUSIONS

The conversion to once-daily tacrolimus in stable liver transplant recipients is an effective and safe therapeutic strategy improving drug compliance.

Pharmacokinetics of a Once Daily Tacrolimus Formulation in First Nations and Caucasian Liver Transplant Recipients

BACKGROUND

Patient ethnicity may influence the pharmacokinetics (PK) of tacrolimus. The Canadian First Nations (FN) constitute a large and increasing segment of the liver transplant population.

OBJECTIVE

To determine whether PK differences exist for a once daily, extended-release formulation of tacrolimus in FN compared to Caucasian (Cauc) liver transplant recipients.

METHODS

Following a 1:1 mg conversion from immediate- to extended-release tacrolimus and achievement of a steady state on the latter formulation, blood samples were drawn at 0, 1, 2, 4, 6, 8 and 24 hours for whole blood tacrolimus levels by commercial immunoassay. CYP3A4 and CYP3A5 allele analyses were performed by polymerase chain reactions.

RESULTS

Nineteen subjects participated in the study (7 FN and 12 Cauc). Unlike Cauc patients, post-conversion Cmin levels did not decrease and were less variable in FN patients. FN patients also had significant shorter Tmax times (1.6±0.2 hours versus 2.8±0.3 hours, p<0.05). Oral clearance, Vd, AUCs, Cmax and Cmin levels were similar in the two cohorts. CYP3A4 genotypes were C/C in both cohorts while the CYP3A5 *1/*3 allele, was present in 2/5 FN and 0/9 Cauc.

CONCLUSIONS

Conversion from immediate- to extended-release tacrolimus results in no significant decrease in Cmin levels, less variable Cmin levels and a shorter time to Tmax in FN compared to Cauc liver transplant recipients.

Once daily tacrolimus conversion in lung transplantation: A prospective study on safety and medication adherence

BACKGROUND

Lung transplantation (LTx) requires a calcineurin inhibitor-based immunosuppressive regimen. A once daily (QD) tacrolimus regimen was developed to increase medication adherence. However, data concerning its safety and efficacy in LTx are lacking.

METHODS

In this prospective study, stable LTx patients were consecutively converted from twice daily (BID) tacrolimus to QD tacrolimus on a 1 mg:1 mg basis. Trough level (C_min), renal function, cholesterol, fasting glucose, potassium and lung function were monitored six months before and up to one year after conversion. Adherence and its barriers were assessed by self-reported questionnaires (Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS) and Identification of Medication Adherence Barriers questionnaire (IMAB)) and blood-based assays (mean C_min and coefficient of variation (CV)).

RESULTS

We included 372 patients, in whom we observed a decrease in tacrolimus C_min of 18.5% (p < 0.0001) post-conversion, requiring subsequent daily dose adaptations in both cystic fibrosis (CF) (n = 72) and non-CF patients (n = 300). We observed a small decrease in eGFR one year post-conversion (p = 0.024). No significant changes in blood creatinine, potassium, fasting glucose, cholesterol or rate of lung function decline were observed. In a subgroup of 166 patients, significantly fewer patients missed doses (8.4% vs. 19.3%, p = 0.016) or had irregular intake post-conversion (19.3% vs. 32.5%, p = 0.019). Mean C_min and CV, as well as the total number of barriers, also decreased significantly post-conversion.

CONCLUSIONS

In LTx, conversion from BID to QD tacrolimus (1 mg:1 mg) requires close monitoring of tacrolimus C_min. QD tacrolimus after transplantation is safe with respect to renal function, metabolic parameters and allograft function and improves LTx recipient adherence.

Conversion From a Twice-Daily to a Once-Daily Tacrolimus Formulation in Kidney Transplant Recipients

BACKGROUND

The aim of the study was to assess bioavailability aspects of tacrolimus formulations during conversion from twice-daily (TAC BID) to once-daily (TAC OD) formulation in 89 stable kidney transplant recipients.

MATERIALS AND METHODS

The study included 89 stable kidney transplant recipients transplanted between 1998 and 2008 (37 female, 52 male, aged 46.0 ± 12.4 years) and followed for 10 years. For a comprehensive comparison of the different tacrolimus formulations, dose-normalized trough levels (ng/mL/mg total daily dose, C/D ratio) and their variability were studied for 10 consecutive visits before and 6 months after conversion.

RESULTS

The mean trough level decreased significantly 14 days after conversion (16%, 5.77 ± 1.94 [5.6, 4.5-6.5] ng/mL, P < .001). There was no significant difference between the tacrolimus trough levels before and 3 months after conversion (6.92 ± 1.89 [6.8, 5.9-8.0] ng/mL, P = .548). The tacrolimus daily dose 3 months after conversion (4.56 ± 1.81 [4.5, 3.5-5.5] mg/d) was significantly higher than the dose before conversion (4.16 ± 1.80 [4.0, 3.0-5.0] mg/d, P = .006). The post-conversion mean TAC trough level (10 measures) (6.6 [6.2-7.0] ng/mL) was similar to preconversion level (6.8 [5.6-7.9] ng/mL, P = .203). C/D ratio as well as C/D intrapatient variability (CV%) did not change during conversion (C/D 1.68 [1.36-2.53] vs 1.74 [1.41 vs 2.31], P = .075; CV% 19.5 [16.4-26.6] vs 24.4 [17.5-28.3], P = .114).

CONCLUSIONS

Conversion from TAC BID to TAC OD is associated with a significant increase in tacrolimus dose during the first 3 months. In a long-term observation both formulations present similar dose-normalized trough levels and variability.

Sequential Cohort Analysis After Liver Transplantation Shows de Novo Extended Release Tacrolimus Is Safe, Efficacious, and Minimizes Renal Dysfunction

The use of once-daily extended-release tacrolimus (ERT) is associated with improved long-term graft and patient survival when compared with twice-daily tacrolimus (BDT), but the underlying reasons for differential survival are unclear. The aim of the study was to compare clinical outcomes known to impact on posttransplant survival for de novo BDT and ERT in liver transplantation (LT) recipients.

METHODS

We conducted a single-center, prospective sequential cohort analysis of adult patients undergoing LT during a change in protocol from de novo BDT to ERT, with a 6-month post-LT follow-up.

RESULTS

A total of 160 transplanted patients were evaluated; 82 were in the BDT group and 78 were in the ERT group. The cohorts were matched for standard variables and a similar proportion in each group received induction interleukin-2 receptor antibody (36% and 31%). There were no significant differences in the measured outcomes of patient and graft survival, biopsy-proven acute rejection episodes, post LT diabetes, and toxicity. A significantly lower number of patients developed chronic kidney disease Stage3-4 in the ERT cohort compared with BDT cohort. In patients with pre-LT renal dysfunction who received antibody induction, estimated glomerular filtration rate decreased significantly in the BDT but not the ERT group.

CONCLUSIONS

We show that once-daily ERT is as safe and efficacious as BDT in de novo LT but optimally conserves renal function post-LT.

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.

Improved Survival in Liver Transplant Patients Receiving Prolonged-release Tacrolimus-based Immunosuppression in the European Liver Transplant Registry (ELTR): An Extension Study

BACKGROUND

We compared, through the European Liver Transplant Registry, long-term liver transplantation outcomes with prolonged-release tacrolimus (PR-T) versus immediate-release tacrolimus (IR-T)-based immunosuppression. This retrospective analysis comprises up to 8-year data collected between 2008 and 2016, in an extension of our previously published study.

METHODS

Patients with <1 month follow-up were excluded; patients were propensity score matched for baseline characteristics. Efficacy measures included: univariate/multivariate analyses of risk factors influencing graft/patient survival up to 8 years posttransplantation, and graft/patient survival up to 4 years with PR-T versus IR-T. Overall, 13 088 patients were included from 44 European centers; propensity score-matched analyses comprised 3006 patients (PR-T: n = 1002; IR-T: n = 2004).

RESULTS

In multivariate analyses, IR-T-based immunosuppression was associated with reduced graft survival (risk ratio, 1.49; P = 0.0038) and patient survival (risk ratio, 1.40; P = 0.0215). There was improvement with PR-T versus IR-T in graft survival (83% versus 77% at 4 y, respectively; P = 0.005) and patient survival (85% versus 80%; P = 0.017). Patients converted from IR-T to PR-T after 1 month had a higher graft survival rate than patients receiving IR-T at last follow-up (P < 0.001), or started and maintained on PR-T (P = 0.019). One graft loss in 4 years was avoided for every 14.3 patients treated with PR-T versus IR-T.

CONCLUSIONS

PR-T-based immunosuppression might improve long-term outcomes in liver transplant recipients than IR-T-based immunosuppression.

Efficacy and safety of prolonged-release tacrolimus in stable pediatric allograft recipients converted from immediate-release tacrolimus - a Phase 2, open-label, single-arm, one-way crossover study

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

Conversion From Immediate-Release Tacrolimus to Prolonged-Release Tacrolimus in Stable Heart Transplant Patients: A Retrospective Study

BACKGROUND

Lifelong adherence with post-transplant immunosuppression is challenging, with nonadherence associated with greater acute rejection (AR) risk.

METHODS

This retrospective study evaluated conversion from immediate-release tacrolimus (IRT) to prolonged-release tacrolimus (PRT), between January 2008 and December 2012 in stable adult heart transplant recipients. Cumulative incidence rate (IR) of AR and infection pre- and postconversion, safety, tacrolimus dose and trough levels, concomitant immunosuppression, and PRT discontinuation were analyzed (intention-to-treat population).

RESULTS

Overall, 467 patients (mean age, 59.3 [SD, 13.3] years) converted to PRT at 5.1 (SD, 4.9) years post transplant and were followed for 3.4 (SD, 1.5) years. During the 6 months post conversion, 5 patients (1.1%; 95% CI, 0.35%-2.48%) had an AR episode and IR was 2.2/100 patient-years (95% CI, 0.91-5.26). Incidence of rejection preconversion varied by time from transplant to conversion. Infection IR was similar post- and preconversion (9.2/100 patient-years [95% CI, 7.4-11.3] vs 10.6/100 patient-years [95% CI, 8.8-12.3], respectively; P = .20). Safety variables remained similar post conversion. The IR of mortality/graft loss was 2.3/100 patient-years (95% CI, 1.7-3.1).

CONCLUSIONS

Conversion from IRT to PRT in heart transplant recipients in Spain was associated with no new safety concerns and appropriate immunosuppressive effectiveness.

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.

Comparative pharmacokinetics of tacrolimus in stable pediatric allograft recipients converted from immediate-release tacrolimus to prolonged-release tacrolimus formulation

This study was a Phase II, open-label, multicenter, single-arm, cross-over study comparing the pharmacokinetics (PK) of tacrolimus in stable pediatric kidney, liver, or heart allograft recipients converted from immediate-release tacrolimus (IR-T) to prolonged-release tacrolimus (PR-T). In Days -30 to -1 of screening period, patients received their IR-T-based regimen; during Days 1-7, patients received study IR-T (same dose as screening). On Day 7, the first 24-hours PK profile was taken; patients were then converted to PR-T (1 mg:1 mg), with a second 24-hours PK profile taken on Day 14. The primary end-point was tacrolimus area under the blood concentration-time curve over 24 hours (AUC₂₄ ); secondary end-points were maximum concentration C_max and concentration at 24 hours C₂₄ . The predefined similarity interval for confidence intervals (CIs) of least squares mean (LSM) ratios was 80%-125%. The PK analysis set comprised 74 pediatric transplant recipients (kidney, n = 45; liver, n = 28; heart, n = 1). PR-T:IR-T LSM ratio (90% CI) was similar overall for AUC₂₄ , _max , and C₂₄ , and for kidney and liver recipients for AUC₂₄ (LSM ratio, kidney 91.8%; liver 104.1%) and C₂₄ (kidney 90.5%; liver 89.9%). Linear relationship was similar between AUC₂₄ and C₂₄ , and between PR-T and IR-T (rho 0.89 and 0.84, respectively), suggesting that stable pediatric transplant recipients can be converted from IR-T to PR-T at the same total daily dose, using the same therapeutic drug monitoring method.

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.

Safety and Efficacy of Once-Daily Prolonged-Release Tacrolimus in Living Donor Liver Transplantation: An Open-Label, Prospective, Single-Arm, Phase 4 Study

BACKGROUND After liver transplantation (LT), nonadherence to immunosuppressants due to the complex regimen can lead to graft rejection and loss. This study assessed the efficacy and safety of conversion from twice-daily tacrolimus (Bid-Tac) to once-daily prolonged-release tacrolimus (OD-Tac) in living donor LT (LDLT) recipients. MATERIAL AND METHODS Among patients who underwent LDLT between November 2015 and October 2016, those who agreed to participate in this study were screened, and those with good general condition and stable liver functions were enrolled. Participants underwent a conversion from Bid-Tac to OD-Tac with a dose ratio of 1: 1 at about 10-14 weeks after LDLT and were followed-up for 24 weeks. RESULTS Thirty-one patients were enrolled. The median number of conversion days after LDLT was 12.3 weeks (range, 10.3-13.8). Adherence was evaluated during the outpatient visits at weeks 2, 4, 8, 16, and 24 after Tac conversion, and 100% adherence was observed at all time points. There were no cases of acute rejection, graft loss, or patient death after Tac conversion. Nineteen cases of adverse events occurred in 11 patients (35.5%), none of which were severe. Alopecia was the most common, affecting 3 (9.7%) patients, followed by pruritus (n=2, 6.45%). There were no changes in renal function or in liver function test, serum glucose level, and lipid profile. CONCLUSIONS Early Tac conversion from Bid-Tac to OD-Tac is safe and feasible. However, further studies are needed to elucidate its long-term effects.

Once-daily tacrolimus in liver transplantation: a 'me-too drug', or a therapeutic advantage

PURPOSE OF REVIEW

To provide latest information on differences between standard tacrolimus (TAC BID) and slow-released formulation of tacrolimus (Advagraf) in liver transplantation (LTx), and to discuss the latter's therapeutic value as a distinct entity.

RECENT FINDINGS

Two articles on de-novo studies, several on conversion and one on survival analysis from the European Liver Transplant Registry published recently showed that low-dose Advagraf immediately after transplantation provided same protection to the kidney as standard dose delayed until day 5, and was associated with lower rejection rate; to maintain the same trough level after late conversion to Advagraf, an approximately 1.25-fold higher dose was needed on average; if studied by questionnaire, conversion improved medication adherence; and registry data provided evidence of long-term survival benefit of Advagraf over TAC BID (7 and 8% graft and patient survival rates over a 3-year period; P < 0.002 and P < 0.003, respectively).

SUMMARY

Pharmacokinetic differences between TAC BID and Advagraf translate into less interpatient and intrapatient variability and improve adherence. If survival benefit of Advagraf administration de novo after LTx as demonstrated by the European Liver Transplant Registry analysis is confirmed in an independent cohort, Advagraf will leave the area of the 'me-too' drugs to become the immunosuppressant of choice.

Conversion From Once-Daily Prolonged-Release Tacrolimus to Once-Daily Extended-Release Tacrolimus in Stable Liver Transplant Recipients

OBJECTIVES

After organ transplant, strategies to simplify the therapeutic regimen may improve adherence and prevent rejection and/or graft loss. The aim of the present study was to evaluate the safety of conversion from once-daily prolonged-release tacrolimus (Advagraf; Astellas Pharma Europe Limited, Middlesex, UK) to once-daily extended-release tacrolimus (Envarsus; Chiesi SAS, Nanterre, France) in stable adult liver transplant recipients.

MATERIALS AND METHODS

This observational study inclu-ded 44 liver transplant patients (median age of 59 y; 63.6% men; median delay after transplant of 72.5 mo). Conversion was based on a 1:0.70 proportion.

RESULTS

Mean dose of tacrolimus was 2.65 ± 1.24 mg/day before conversion and 2.09 ± 1.68 mg/day after conversion (P < .05), with ratio of 1:0.79. Mean serum tacrolimus trough level increased after conversion (4.92 ± 1.65 vs 5.60 ± 2.89 ng/mL; P < .05), with ratio of 1:1.14. Six months after conversion, mean dose of tacrolimus was 1.65 ± 0.93 mg/day (ratio of 1:0.62) and mean serum tacrolimus trough level was 4.82 ± 1.85 ng/mL, similar to the initial level before conversion. At the end of follow-up, 2 patients had returned to once-daily prolonged-release tacrolimus because of adverse effects (allergy, digestive trouble), which resolved thereafter. The mean cost of tacrolimus therapy was 5.54 ± 2.29 Euros/patient/day before conversion and 4.11 ± 2.32 Euros/patient/day after conversion (P < .05).

CONCLUSIONS

Conversion from prolonged-release to extended-release tacrolimus in stable liver transplant patients is safe and cost-effective; however, initially, dose adaptations and careful monitoring are required.

Emerging drugs for prevention of T-cell mediated rejection in liver and kidney transplantation

INTRODUCTION

Acute and chronic graft rejection continues to be an important problem after solid organ transplantation. With the introduction of potent immunosuppressive agents such as calcineurin inhibitors, the risk of rejection has been significantly reduced. However, the adverse effects of life-long immunosuppression remain a concern, and there exist a fine balance between over-immunosuppression and risk of rejection. Areas covered: In this review, the current standard of care in immunosuppressive therapy, including the use of steroids, calcineurin inhibitors, mycophenolate prodrugs and mammalian target of rapamycin inhibitors, will be discussed. Newer immunosuppressive agents showing promising early data after liver and kidney transplantation will also be explored. Expert Opinion: Currently, calcineurin inhibitors continue to be a vital component of immunosuppressive therapy after solid organ transplantation. Although minimization and avoidance strategies have been developed, the ultimate goal of inducing tolerance remains elusive. Newer emerging agents should have potent and specific immunosuppressive activity, with minimal associated side effects. An individualized approach should be adopted to tailor immunosuppression according to the different needs of recipients.

Systematic Review and Meta-Analysis of Tacrolimus versus Ciclosporin as Primary Immunosuppression After Liver Transplant

Background and Aims

Several meta-analyses comparing ciclosporin with tacrolimus have been conducted since the 1994 publication of the tacrolimus registration trials, but most captured data from randomized controlled trials (RCTs) predating recent improvements in waiting list prioritization, induction protocols and concomitant medications. The present study comprised a systematic review and meta-analysis of ciclosporin and tacrolimus in liver transplant recipients using studies published since January 2000.

Methods

Searches of PubMed, the Cochrane Library and EMBASE identified RCTs of tacrolimus and ciclosporin as the immunosuppressant in adult primary liver transplant recipients, published between January 2000 and August 6, 2014. A random effects meta-analysis was conducted to evaluate the relative risk of death, graft loss, acute rejection (AR), new-onset diabetes after transplantation (NODAT) and hypertension with tacrolimus relative to ciclosporin at 12 months.

Results

The literature search identified 11 RCTs comparing ciclosporin with tacrolimus. Relative to ciclosporin, tacrolimus was associated with significantly improved outcomes in terms of patient mortality (risk ratio [RR] with ciclosporin of 1.26; 95% confidence interval [95%CI] 1.01–1.58). Tacrolimus was superior to ciclosporin in terms of hypertension (RR with ciclosporin 1.26; 95%CI 1.07–1.47), but inferior in terms of NODAT (RR with ciclosporin 0.60; 95%CI 0.47–0.77). There were no significant differences between ciclosporin and tacrolimus in terms of graft loss or AR.

Conclusions

Meta-analysis of RCTs published since 2000 showed tacrolimus to be superior to ciclosporin in terms of patient mortality and hypertension, while ciclosporin was superior in terms of NODAT. No significant differences were identified in terms of graft loss or AR. These findings provide further evidence supporting the use of tacrolimus as the cornerstone of immunosuppressive therapy in liver transplant recipients.

Risk Factors for the Adverse Events after Conversion from Twice-Daily to Once-Daily Tacrolimus in Stable Liver Transplantation Patients

Despite the therapeutic equivalence between twice-daily and once-daily tacrolimus, patient safety after conversion is still a concern. We reviewed 218 liver transplantation (LT) patients who converted twice-daily to once-daily tacrolimus between May 2011 and January 2014. Thirty (13.8%) patients had adverse events after conversion, with a liver function test (LFT) abnormality being the most common adverse event (n = 17). Despite the decrease in serum tacrolimus of > 30% after conversion, none of the patients who were converted to a dosage ratio (once-daily tacrolimus dosage: twice-daily tacrolimus dosage) > 1 had an LFT abnormality. Most patients with an LFT abnormality improved after increasing the once-daily tacrolimus dosage (n = 2), returned to a previous medication, and/or added another immunosuppressant (n = 15). One patient had acute cellular rejection, which improved after steroid pulse treatment, and another patient had graft failure. In patients with a dosage ratio ≤ 1, the conversion time within 5 years after LT was the only significant risk factor for an LFT abnormality after conversion (odds ratio: 11.850, 95% confidence interval: 1.321-106.325, P = 0.027). In conclusion, the dosage ratio and time after LT should be carefully considered during conversion from twice-daily to once-daily tacrolimus.

Favorable longterm outcomes of liver transplant recipients treated de novo with once-daily tacrolimus: Results of a single-center cohort

The once-daily prolonged-release formulation of tacrolimus has been recently related with significant graft and patient mid-term survival advantages; however, practical information on the de novo administration after liver transplantation and longterm outcomes is currently lacking. This study is a 5-year retrospective analysis of a single-center cohort of liver transplant recipients treated de novo with once-daily tacrolimus (April 2008/August 2011). The study cohort consisted of 160 patients, including 23 with pretransplant renal dysfunction, with a median follow-up of 57.6 months (interquartile range, 46.6-69.0). Tacrolimus target trough levels were 5-10 ng/mL during the first 3 months after transplant, reducing progressively to <7 ng/mL after the first posttransplant year. Once-daily tacrolimus was withdrawn in 35 (21.8%) patients during follow-up, mostly due to renal dysfunction and/or metabolic syndrome. The biopsy-proven acute rejection rate was 12.5% with no cases of steroid-resistant rejection. The cumulative incidence of de novo diabetes, hypertension, and dyslipidemia were 16.9%, 31.2%, and 6.5%, respectively. Hepatocellular carcinoma recurrence rate was 2.8%. Renal function remained stable after the sixth month after transplant with a mean estimated glomerular filtration rate of 77.7 ± 19.6 mL/minute/1.73 m(2) at 5 years. None of our patients developed chronic kidney disease stage 4 or 5. Patient survival at 1, 3, and 5 years was 96.3%, 91.9%, and 88.3%, respectively. Overall survival of patients with Model for End-Stage Liver Disease (MELD) score > 25 points was not significantly different. In conclusion, our study suggests that immunosuppression based on de novo once-daily tacrolimus is feasible in routine clinical practice, showing favorable outcomes and outstanding longterm survival even in patients with high MELD scores. Liver Transplantation 22 1391-1400 2016 AASLD.

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.

Overview of extended release tacrolimus in solid organ transplantation

Tacrolimus (Prograf^©, Astellas Pharma Europe Ltd, Staines, United Kingdom; referred to as tacrolimus-BID) is an immunosuppressive agent to prevent and treat allograft rejection in kidney transplant recipients in combination with mycophenolate mofetil, corticosteroids, with or without basiliximab induction. The drug has also been studied in liver, heart and lung transplant; however, these are currently off-label indications. An extended release tacrolimus formulation (Advagraf^©, Astagraf XL^©) allows for once-daily dosing, with the potential to improve adherence. Extended release tacrolimus has similar absorption, distribution, metabolism and excretion to tacrolimus-BID. Phase I pharmacokinetic trials comparing extended release tacrolimus and tacrolimus-BID have demonstrated a decreased maximum concentration (C_max) and delayed time to maximum concentration (t_max) with the extended release formulation; however, AUC_0-24 was comparable between formulations. Overall extended release tacrolimus has a very similar safety and efficacy profile to tacrolimus-BID. It is not recommended in the use of liver transplant patient’s due to the increased risk of mortality in female recipients. There has been minimal data regarding the use of extended release tacrolimus in heart and lung transplant recipients. With the current data available for all organ groups the extended release tacrolimus should be dosed in a 1:1 fashion, the exception may be the cystic fibrosis population where their initial dose may need to be higher.

A Pilot Study of the Pharmacokinetics of the Modified-Release Once-Daily Tacrolimus Formulation Administered to Living-Donor Liver Transplant Recipients

OBJECTIVES

Sustained-release once-daily tacrolimus pharmacokinetics have not yet been characterized in de novo living-donor liver transplant recipients. Here, a 12-week, phase IV, single center, open-label, prospective pilot study was conducted to investigate the pharmacokinetics of this formulation in these patients.

MATERIALS AND METHODS

Patients received continuous intravenous infusion of tacrolimus on days 0 to 5 after transplant, which was followed by oral once-daily sustained-release tacrolimus. Two 24-hour pharmacokinetics profiles were generated for 10 patients on days 6 and 14. Secondary endpoints were minimum (trough level) and maximum whole blood concentrations, time to maximum concentration, and incidences of acute rejection, patient and graft survival, and adverse events.

RESULTS

Mean doses (± standard deviation) of sustained-release tacrolimus on days 6 and 14 were 0.14 ± 0.03 and 0.17 ± 0.04 mg/kg. Levels were within the recommended range throughout the study. When the actual dose was examined, area under the curve from 0 to 24 hours on day 14 was 1.8-fold higher than that on day 6 (423.9 vs 235.7 ng × h/mL). When tacrolimus was normalized to 0.1 mg/kg, area under the curve from 0 to 24 hours on day 14 was 1.5-fold higher than on day 6 (279.3 vs 183.4 ng × h/mL). When we used the actual dose, we found the correlation coefficient between area under the curve from 0 to 24 hours and trough level to be higher on day 6 (r = 0.87) than on day 14 (r = 0.691). No acute rejections, graft losses, patient deaths, or drug-related adverse events were reported.

CONCLUSIONS

Initial intravenous followed by sustained-release tacrolimus was safe and efficacious in living-donor liver transplant recipients. The mean area under the curve from 0 to 24 hours on day 14 was higher than previously reported; this difference may reflect cautious dosing regimens.

Evaluating the Cost-Effectiveness of Prolonged-Release Tacrolimus Relative to Immediate-Release Tacrolimus in Liver Transplant Patients Based on Data from Routine Clinical Practice

Background

As of 2014, there were approximately 8300 patients with a functioning liver transplant in the UK Transplant Registry, with 880 liver transplants performed in 2013–2014 alone. Tacrolimus, typically used in combination with steroids and mycophenolate mofetil, currently represents the cornerstone of post-transplant immunosuppression in liver transplant recipients.

Objectives

The objective of the present study was to evaluate the cost-effectiveness of prolonged-release (PR) tacrolimus (Advagraf^®, Astellas Pharma Inc., Tokyo, Japan) versus branded immediate-release (IR) tacrolimus (Prograf^®, Astellas Pharma Inc., Tokyo, Japan) in liver transplant recipients in the UK.

Methods

A model was developed in Microsoft Excel to estimate costs associated with immunosuppressive medications and retransplantation. Three-year patient and graft survival data were taken from a recent retrospective registry analysis and dose data were taken from prescribing information. Costs in 2014 pounds sterling were taken from the British National Formulary and the National Health Service National Tariff.

Results

Over a 3-year time horizon, the numbers needed to treat with PR tacrolimus relative to IR tacrolimus were 14 to avoid one graft loss and 18 to avoid one death. The model was sensitive to dosing assumptions, with incremental cost estimates varying between a saving of £1642 (standard deviation £885) per patient, assuming the same per-kilogram dosing of PR tacrolimus (Advagraf^®) and IR tacrolimus (Prograf^®) and an increase of £1350 (£964) using RCT dose data.

Conclusion

Data from a recent analysis of routine clinical practice data in liver transplant recipients on PR tacrolimus and IR tacrolimus showed significant differences in long-term graft survival in favor of PR tacrolimus. Modeling these data in the UK showed that, over a 3-year time horizon, one graft would be saved for every 14 patients treated with PR tacrolimus with minimal impact on costs when compared with branded IR tacrolimus (Prograf^®).

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.

Evaluating the Cost-Effectiveness of Prolonged-Release Tacrolimus Relative to Immediate-Release Tacrolimus in Liver Transplant Patients Based on Data from Routine Clinical Practice

BACKGROUND

As of 2014, there were approximately 8300 patients with a functioning liver transplant in the UK Transplant Registry, with 880 liver transplants performed in 2013-2014 alone. Tacrolimus, typically used in combination with steroids and mycophenolate mofetil, currently represents the cornerstone of post-transplant immunosuppression in liver transplant recipients.

OBJECTIVES

The objective of the present study was to evaluate the cost-effectiveness of prolonged-release (PR) tacrolimus (Advagraf^®, Astellas Pharma Inc., Tokyo, Japan) versus branded immediate-release (IR) tacrolimus (Prograf^®, Astellas Pharma Inc., Tokyo, Japan) in liver transplant recipients in the UK.

METHODS

A model was developed in Microsoft Excel to estimate costs associated with immunosuppressive medications and retransplantation. Three-year patient and graft survival data were taken from a recent retrospective registry analysis and dose data were taken from prescribing information. Costs in 2014 pounds sterling were taken from the British National Formulary and the National Health Service National Tariff.

RESULTS

Over a 3-year time horizon, the numbers needed to treat with PR tacrolimus relative to IR tacrolimus were 14 to avoid one graft loss and 18 to avoid one death. The model was sensitive to dosing assumptions, with incremental cost estimates varying between a saving of £1642 (standard deviation £885) per patient, assuming the same per-kilogram dosing of PR tacrolimus (Advagraf^®) and IR tacrolimus (Prograf^®) and an increase of £1350 (£964) using RCT dose data.

CONCLUSION

Data from a recent analysis of routine clinical practice data in liver transplant recipients on PR tacrolimus and IR tacrolimus showed significant differences in long-term graft survival in favor of PR tacrolimus. Modeling these data in the UK showed that, over a 3-year time horizon, one graft would be saved for every 14 patients treated with PR tacrolimus with minimal impact on costs when compared with branded IR tacrolimus (Prograf^®).

Once-daily prolonged release tacrolimus in liver transplantation: Experts' literature review and recommendations

The efficacy and safety of tacrolimus (Tac) twice daily (bid) and once a day (qd) formulations are considered to be similar. However, the available information regarding initiation of Tac qd is sparse, and practical information is lacking. On the basis of a literature review, clinical efficacy, and safety trials, French experts in the liver transplantation field were asked to highlight pharmacokinetic (PK) differences between both formulations to assess efficacy and safety of the qd formulation in the context of de novo initiation or conversion and to provide their recommendations for initiation and day-to-day management of Tac qd. The same efficacy and safety profile is found for both immediate-release and prolonged-release Tac. PK differences carry on absorption because of the difference in formulations but not on metabolism or excretion. Tac qd offers a better reproducibility in exposure than Tac bid but is associated with an increased risk of disturbed absorption in case of a change in intestinal motility. The same therapeutic drug monitoring with Tac qd and bid could be applied, based on minimal concentration (trough level; C(min)), as there is a similar strong correlation between C(min) and the area under the curve (AUC) for both formulations. Different protocols for Tac qd initiation were described through numerous studies, except for early conversion: initiation on day 0, using 0.10 to 0.20 mg/kg/day as monotherapy, or lower dosages in case of concomitant immunosuppressant treatment or poor graft quality; early conversion from day 5 to 6 months, preferably before hospital discharge, using a 1 to 1.3 mg/kg/day schedule and with first C(min) assessment 48 hours after the conversion; and later conversion (>6 months posttransplantation) using a milligram-to-milligram dosage schedule, and with dose adjustment based on weekly C(min) measurement. Experts underline that an increase in treatment adherence was expected using Tac qd in liver recipients. In conclusion, Tac qd has the same efficacy and safety profile as Tac bid. De novo introduction or later conversion are well documented but could differ from day-to-day practice.

Improved survival in liver transplant recipients receiving prolonged-release tacrolimus in the European Liver Transplant Registry

This study was a retrospective analysis of the European Liver Transplant Registry (ELTR) performed to compare long-term outcomes with prolonged-release tacrolimus versus tacrolimus BD in liver transplantation (January 2008-December 2012). Clinical efficacy measures included univariate and multivariate analyses of risk factors influencing graft and patient survival at 3 years posttransplant. Efficacy measures were repeated using propensity score-matching for baseline demographics. Patients with <1 month of follow-up were excluded from the analyses. In total, 4367 patients (prolonged-release tacrolimus: n = 528; BD: n = 3839) from 21 European centers were included. Tacrolimus BD treatment was significantly associated with inferior graft (risk ratio: 1.81; p = 0.001) and patient survival (risk ratio: 1.72; p = 0.004) in multivariate analyses. Similar analyses performed on the propensity score-matched patients confirmed the significant survival advantages observed in the prolonged-release tacrolimus- versus tacrolimus BD-treated group. This large retrospective analysis from the ELTR identified significant improvements in long-term graft and patient survival in patients treated with prolonged-release tacrolimus versus tacrolimus BD in primary liver transplant recipients over 3 years of treatment. However, as with any retrospective registry evaluation, there are a number of limitations that should be considered when interpreting these data.

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.

Lower variability in 24-hour exposure during once-daily compared to twice-daily tacrolimus formulation in kidney transplantation

INTRODUCTION

Tacrolimus has originally been registered as a twice-daily formulation (Prograf, Tac BID), although a once-daily formulation (Advagraf, Tac QD) is also available. A reduced intrapatient variability of Tac Cmin, a surrogate marker for 24-hour drug exposure (AUC0-24), has been suggested. The variability of AUC0-24 has never been studied prospectively yet. The purpose of this study was to investigate the change in intrapatient variability of Tac AUC0-24 after converting from Tac BID to Tac QD.

METHODS

Forty renal transplant patients on Tac BID were converted on a 1:1 (mg/mg) basis to Tac QD in an investigator-driven comparative pharmacokinetic (PK) study. AUC0-24 was determined five times before and after conversion. Duplicate samples were collected by the patients themselves using the dried blood spot method. The main outcome measure is the change in intrapatient variability of AUC0-24 expressed as coefficient of variation (CV). Moreover, the influence of Cyp3A5 genotype polymorphism on the change in CV was studied.

RESULTS

In total, 400 AUC0-24 profiles were available for analysis. Conversion to Tac QD resulted in a significant improvement in intra-patient CV from 14.1% to 10.9% (P=0.012). Patients with the Cyp3A5*1/*3 genotype (n=11) had a numerically larger improvement in CV than patients with the CYP3A5*3/*3 genotype.

CONCLUSION

Intrapatient CV of Tac AUC0-24 improved after converting from Tac BID to Tac QD in stable renal transplant patients, especially in patients with the CYP3A5*1/3 genotype. Given the very strict protocol of this PK study, this improvement is most likely due to the different intrinsic PK properties of Tac QD and Tac BID.

Conversion from twice daily tacrolimus capsules to once daily extended-release tacrolimus (LCP-Tacro): phase 2 trial of stable liver transplant recipients

LCP-Tacro is an extended-release formulation of tacrolimus designed for once-daily dosing. Studies in renal transplantation demonstrate greater bioavailability with similar safety and efficacy vs. twice-daily tacrolimus capsules. In this phase 2 study, adult stable liver transplant patients on tacrolimus capsules (Prograf) twice-daily were converted to tacrolimus tablets (LCP-Tacro) once-daily; patients continued on LCP-Tacro once-daily for days 8-21; target trough levels were 5-15 ng/mL; 24-hour pharmacokinetic (PK) assessments were done on days 7 (baseline pre-switch), 14, and 21. A 6 month extension study phase evaluated PK and safety following a total of 52 weeks of LCP-Tacro. Fifty-seven patients completed LCP-Tacro dosing in the core study; 43 completed the extension phase. The mean conversion ratio was 0.71 (Prograf:LCP-Tacro). PK data demonstrated consistent exposure (AUC) at the lower conversion dose. Cmax , Cmax /Cmin ratio, percent fluctuation and swing were significantly (P<0.001) lower and Tmax significantly (P<0.001) longer for LCP-Tacro vs. Prograf. AUC24 and Cmin correlation coefficients after 7 and 14 days of therapy were ≥0.93. There were no significant differences in PK parameters at week 26 vs. 14. One patient experienced an unrelated serious adverse event (SAE) during the core study and discontinued. There were six unrelated SAEs in the extension and 1 possibly related (rejection) that resolved; there were 3 discontinuations due to AEs during the extension. In this study, patients were safely converted from Prograf twice-daily to LCP-Tacro. The greater bioavailability of LCP-Tacro allowed for once-daily dosing and similar (AUC) exposure at a dose approximately 30% less than the total daily dose of Prograf. LCP-Tacro displayed significantly lower peak and peak-trough fluctuations. LCP-Tacro administered over one year was well tolerated with no new safety concerns.

Tacrolimus effects and side effects after liver transplantation: is there a difference between immediate and extended release?

BACKGROUND

Immunosuppressive therapy after orthotopic liver transplantation (OLT) requires a high degree of patient compliance to guarantee safety and avoid side effects. In 2007, prolonged-release tacrolimus was launched in Europe to improve compliance. In this prospective observational crossover single-center trial, we analyzed effects and side effects of prolonged-release tacrolimus in OLT patients.

METHODS

LT patients at our center were included if they were older than l8 years of age, had had the procedure at least 6 months prior, and were outpatients currently on twice-daily tacrolimus. Patients were observed for 6 months before switching to once-daily tacrolimus. Patient history, clinical examination, and laboratory examinations were recorded on inclusion as well as after 3, 6, 9, 12, and 18 months.

RESULTS

The rates of rejection, hypertension, hypercholesterolemia, and diabetes mellitus were compared during twice-daily and once-daily tacrolimus. Similarly, laboratory parameters were identical during both periods with the exception of glycated hemoglobin, which was significantly elevated under once-daily tacrolimus (P = .00l).

CONCLUSION

Converting patients to extended-release tacrolimus with was safe in terms of rejection, hypertension, and hypercholesterolemia as well as renal and liver functions. Further investigations concerning pharmacokinetics and glucose metabolism will be needed to evaluate prolonged-release tacrolimus.

Pharmacokinetic study of conversion from tacrolimus twice-daily to tacrolimus once-daily in stable lung transplantation

BACKGROUND

Tacrolimus twice-daily (TAC BID) is widely used in lung transplantation (LT), but there are little data on the use of tacrolimus once-daily (TAC QD) in this population. The objective of this study was to compare the pharmacokinetics (PK) of TAC BID and TAC QD in stable, adult LT patients.

METHODS

Phase II, open-label, single-center, single-arm, prospective pilot PK study. Nineteen LT recipients with more than 6 months of postoperative follow-up and on TAC BID-based therapy were converted to TAC QD on a 1:1 (mg/mg) basis. Patients had been stable during the previous 3 months, and cystic fibrosis patients were excluded. One 24-hr PK profile was obtained on day -14 while patients were under TAC BID. A second PK profile was obtained 14 to 28 days after switching (day 0) to the same dose of TAC QD. Pre- and post-switch 24-hr PK profiles were compared.

RESULTS

Mean AUC0-24 hr was 279.8 ng mL/hr for TAC BID and 278.7 ng mL/hr for TAC QD (P=0.92). AUC0-12 hr of TAC BID was higher than the AUC12-24 hr. There was a good correlation between AUC0-24 hr and C24 for both QD (r=0.96) and BID (r=0.94) formulations. There were no differences in the adverse events occurring with the two formulations.

CONCLUSIONS

Tacrolimus bioavailability in steady state is similar in BID and QD formulations after conversion in stable LT recipients, excluding those with cystic fibrosis. Thus, our results indicate TAC BID can be safely switched to the more convenient QD formulation in this population.

Increased adherence eight months after switch from twice daily calcineurin inhibitor based treatment to once daily modified released tacrolimus in heart transplantation

Background

Modified-release tacrolimus (TAC) is a new, once-daily oral formulation of the established immunosuppressive agent TAC. This study evaluated long-term patient adherence, as well as safety and efficacy, in stable patients after heart transplantation (HTx) who switched from a conventional twice daily calcineurin inhibitor-based regimen (TAC or cyclosporine A [CsA]) to a once-daily modified-release TAC regimen.

Methods

Stable patients were switched from conventional TAC or CsA (twice-daily dosing) to modified-release TAC (once-daily dosing) according to manufacturer’s recommendations using a pre-experimental design. Self-reported adherence was assessed at baseline and 8 months after the switch with the Basel Assessment of Adherence with Immunosuppressive Medication Scale (BAASIS). Additionally, routine laboratory values were analyzed 8 months after switch.

Results

Of 76 patients (58 male, 18 female) initially included, 72 were available for statistical analysis, as modified-release TAC was discontinued due to diarrhea in one patient and gastrointestinal discomfort in three patients. Overall nonadherence at baseline for any of the four BAASIS items was 75.0% versus 40.3% after 8 months (P<0.0001). After 8 months, adherence was improved in 41 patients (56.9%), unchanged in 27 (37.5%), and reduced in four patients (5.6%). The BAASIS visual analog scale score improved significantly from 87.0% ± 13.5% to 97.5% ± 5.7% (P<0.0001). No significant changes were observed for hematological, renal, or liver function parameters after 8 months (all P=not significant).

Conclusion

To our knowledge, this is the first study in stable patients after HTx to demonstrate a significant improvement in long-term (ie, 8-month) patient adherence after the switch to modified-release TAC. Modified-release TAC was generally well tolerated. Further studies are currently underway to investigate long-term safety after HTx of various calcineurin inhibitors for prevention of rejection and occurrence of side effects.

Increased medication compliance of liver transplant patients switched from a twice-daily to a once-daily tacrolimus-based immunosuppressive regimen

BACKGROUND

Compliance with immunosuppressive therapy plays a major role in the long-term success of liver transplantation. Thus, the development of strategies to promote compliance of liver transplant patients and its evaluation over time are of particular interest.

OBJECTIVE

The main objective of this study was to compare medication compliance rates among liver transplant patients over time after transplantation where switched from a twice- to once-daily tacrolimus-based regimen.

METHODS

Sixty-five liver transplant patients being administered tacrolimus-based therapy were classified into three subgroups with regard to time posttransplantation. Medication compliance with tacrolimus-based therapy was measured using an electronic medication event monitoring system over a 12-month period: for 6 months tacrolimus was administered twice-daily and for 6 months, once-daily. Dosing, taking, and timing compliance as well as drug holidays were compared intra-individually between twice- and once-daily intake and among the three subgroups. In addition, patient compliance and quality of life were evaluated using questionnaires.

RESULTS

A per protocol analysis of electronically obtained data showed 63 patients to be eligible. The resulting dosing, taking, and timing compliance rates of the patients were higher during the once-daily dosing period. No significant differences in compliance rates with tacrolimus therapy were observed among three subgroups independent of the dosing regimen. More patients failed the correct timing of the evening compared to the morning dose. Missing doses occurred particularly during weekends. Compliance variables measured by questionnaires (Morisky score, self-report, Medication Experience Scale for Immunosuppressants (MESI) score) and the Hospital Anxiety and Depression Scale score were similar in the two dosing periods. The short-form health survey (SF-36) score was higher with once-daily intake.

CONCLUSION

The high measured compliance rates did not vary significantly dependent upon the time after transplantation. Nevertheless, compliance rates were greater using once-daily tacrolimus dosing.

Conversion from twice daily tacrolimus to once daily tacrolimus in long-term stable liver transplant recipients: a single-center experience with 394 patients

After organ transplantation, strategies for simplifying the therapeutic regimen may improve adherence and prevent acute organ rejection and/or late graft loss. The aim of the present study was to evaluate the safety and efficacy of conversion from a tacrolimus (TAC) twice daily (bid) formulation to a once daily (qd) formulation in a large cohort of adult liver transplantation (LT) patients. This retrospective, observational, single-center study included 394 LT patients with at least 6 months' posttransplant follow-up and no rejection episodes in the last 3 months. The conversion from a bid formulation to a qd formulation was based on a 1:1 ratio. The mean age at the time of conversion was 53 years (range = 18-72 years); 66% were men. The main indication for LT was alcoholic cirrhosis (41%). The mean conversion time after LT was 74 months (range = 6-218 months). The mean serum TAC trough level decreased after conversion (6.1 ± 5.6 ng/mL before conversion versus 4.9 ± 2.5 ng/mL after conversion, P < 0.05). After a mean follow-up of 24 months after conversion, 6 patients had converted to cyclosporine, 14 patients had stopped all calcineurin inhibitors, 16 patients had returned to TAC bid, and 358 patients were still on TAC qd. Acute rejection episodes were observed in 7 patients. In conclusion, the results of our experience indicate that the conversion from a TAC bid formulation to a qd formulation is a safe and effective strategy for the management of stable LT patients.

Comparison of pharmacokinetics and pharmacogenetics of once- and twice-daily tacrolimus in the early stage after renal transplantation

BACKGROUND

This study investigated pharmacokinetic and pharmacogenetic differences between a modified-release once-daily formulation of tacrolimus (Tac-QD) and the original formulation requiring twice-daily intake (Tac-BID) in de novo renal transplant recipients.

METHODS

Forty-seven and 25 patients who received Tac-BID and Tac-QD, respectively, were enrolled. The pharmacokinetics and CYP3A5 6986A>G and ABCB1 3435C>T pharmacogenetics of each formulation were analyzed on day 28 posttransplantation.

RESULTS

The dose-adjusted trough level (C0) and area under the concentration-time curve (AUC0-24) of tacrolimus were approximately 25% lower for Tac-QD than Tac-BID. However, there was a good correlation between the AUC0-24 and C0 in the Tac-BID and Tac-QD groups (r=0.575, P<0.001; and r=0.638, P<0.001, respectively) and a similar coefficient in each regression equation. The dose-adjusted AUC0-24 was approximately 25% lower in carriers of the CYP3A*1 allele (CYP3A5 expressers), but not individuals with the CYP3A*3/*3 genotype (nonexpressers), for TAC-QD than Tac-BID. In the Tac-QD group, the interpatient variability for dose-adjusted parameters was small, and the interquatile ranges of dose-adjusted parameters differed between CYP3A5 expressers and nonexpressers and did not overlap. The ABCB1 polymorphism was not associated with any pharmacokinetic parameters of Tac-QD.

CONCLUSIONS

C0-guided monitoring may lead to similar AUC0-24 values for both formulations. However, to maintain the same AUC0-24 value, a higher dose of Tac-QD than Tac-BID may be needed, especially for CYP3A5 expressers, in the early stage posttransplantation. The narrow interindividual variability of Tac-QD pharmacokinetics and its difference between CYP3A5 expressers and nonexpressers might contribute to a dosing strategy based on CYP3A5 genotype.

Pharmacokinetics in stable kidney transplant recipients after conversion from twice-daily to once-daily tacrolimus formulations

BACKGROUND

A prolonged-release formulation of tacrolimus for once-daily administration (Tacrolimus QD) has been developed to offer potential improvements in patient adherence. This study compared the pharmacokinetics (PK) of tacrolimus in stable kidney transplant recipients before and after conversion from twice-daily tacrolimus (Tacrolimus BID) to Tacrolimus QD.

METHODS

This was an open-label, multicenter replicate design study in stable adult kidney transplant recipients (≥6 months posttransplantation) maintained on Tacrolimus BID. Patients underwent four sequential 14-day treatment periods of alternating Tacrolimus BID and QD (mg:mg conversion). Four 24-hour PK profiles were collected, one on the last day of each treatment period. Adverse events were also reported.

RESULTS

A total of 60 of 69 patients completed all 4 PK profiles. Steady-state tacrolimus area under the curve from 0 to 24 hours and Cmin were comparable for both formulations, with treatment ratio means (90% confidence intervals) of 92.9% (89.8%-96.0%) and 90.9% (87.3%-94.6%), respectively (acceptance interval: 80%-125%). Both formulations were well tolerated, with renal function remaining stable over the 8-week period. There was a good correlation between area under the curve from 0 to 24 hours and Cmin for Tacrolimus QD and BID (r = 0.88 and 0.82, respectively). The relationship between these two parameters was also similar.

CONCLUSIONS

The results of this study provide evidence for safe conversion from Tacrolimus BID to QD with appropriate trough concentration monitoring.

The once-daily formulation of tacrolimus: a step forward in kidney transplantation?

Nonadherence is a critical issue in transplantation. Recently, Astellas designed a once-daily-extended release formulation of tacrolimus (Tac). Despite initial reports showing bioequivalence of Tac once-daily (Advagraf) with the original formulation requiring twice-daily intake (Tac twice-daily, Prograf), several groups have now shown a sustained decrease in Tac exposure upon conversion from Prograf to Advagraf. Here, we discuss the possible reasons for this observation and how it could affect the expected benefits of Advagraf, and we comment on the fact that a similar lack of bioequivalence might prevail with generic immunosuppressive drugs.