Budget impact of switching from an immediate-release to a prolonged-release formulation of tacrolimus in renal transplant recipients in the UK based on differences in adherence

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.

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.

Conversion From Twice-Daily to Once-Daily Tacrolimus Among Egyptian Living-Donor Kidney Allograft Recipients: A Single-Center Experience

OBJECTIVES

Adherence to immunosuppression and minimization of drug exposure are important con-siderations in preventing rejection and maximizing transplant outcomes. The once-daily tacrolimus protocol confers potential benefit by simplifying immunosuppressive regimens, thereby improving adherence among transplant recipients. Studies of stable transplant recipients have suggested that once-daily tacrolimus is bioequivalent to twice-daily tacrolimus and is noninferior to twice-daily tacrolimus with a concentration-dependent rejection risk. Our aim was to evaluate the safety and efficacy of conversion from twice-daily tacrolimus formulation to a once-daily formulation among a cohort of adult living related-donor renal transplant patients as a single-center experience.

MATERIALS AND METHODS

This prospective, one arm, single-center study included 238 patients with at least 12 months posttransplant follow-up and no rejection episodes in the last 3 months. Conversion from twice-daily to once-daily formulation was based on a 1:1 ratio.

RESULTS

The mean tacrolimus dose was 4.7 ± 2.7 mg/day preconversion versus 4.9 ± 3.2 mg/day postconversion (P = .8). The mean tacrolimus level was 7.4 ± 3.4 versus 6.1 ± 2.8 ng/mL (P = .75). Of total patients, 45% were maintained on a tacrolimus dose of less than 2 ng/dL. Renal function was comparable before and after conversion (mean serum creatinine was 1.25 ± 0.88 vs 1.23 ± 0.78 mg/dL; P = .9). The incidence of biopsy-proven acute rejection was 19.7% preconversion versus 4.2% postconversion. Graft and patient survival rates were comparable between the 2 tacrolimus formulations. Once-daily tacrolimus also had favorable effects on blood pressure, lipid profile, and glucose tolerance.

CONCLUSIONS

Conversion from conventional tacrolimus (twice daily) to once-daily tacrolimus may be a valuable option with comparable patient and graft survival and may lead to improved adherence that may be reflective of better long-term results. It should be considered for de novo immunosuppression among living-donor renal allotransplant recipients.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

LIMITATIONS

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

FUTURE WORK

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

CONCLUSION

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

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013189.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Clinical Evaluation of Modified Release and Immediate Release Tacrolimus Formulations

The science of drug delivery has evolved considerably and has led to the development of multiple sustained release formulations. Each of these formulations can present particular challenges in terms of clinical evaluation and necessitate careful study to identify their optimal use in practice. Tacrolimus is an immunosuppressive agent that is widely used in organ transplant recipients. However, it is poorly soluble, has an unpredictable pharmacokinetic profile subject to important genetic polymorphisms and drug-drug interactions, and has a narrow therapeutic index. For these reasons, it represents an agent that could benefit from modified release formulations to overcome these limitations. The objective of this review is to discuss the clinical evaluation of immediate and modified release tacrolimus formulations in renal transplant recipients. Clinical trials from early development of immediate release tacrolimus to formulation-specific post-marketing trials of modified release tacrolimus formulations are reviewed with an emphasis on key elements relating to trial design end endpoint assessment. Particular elements that can be addressed with formulation alterations, such as pharmacokinetics, pharmacogenomics, and toxicity and corresponding clinical evaluations are discussed. In addition, current knowledge gaps in the clinical evaluation of immediate and modified release tacrolimus formulations are discussed to highlight potential avenues for the future development of different tacrolimus formulations with outcomes relevant to the regulators, the transplant community, and to transplant recipients. This review shows that new formulations may alter tacrolimus bioavailability, alleviate certain adverse events while potentially enhancing patient convenience.

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.

Cost utility analysis of immunosuppressive regimens in adult renal transplant recipients in England and Wales

BACKGROUND

End-stage renal disease is the irreversible final stage of chronic kidney disease and is fatal when not managed by either transplantation or dialysis. Transplantation is generally preferred over dialysis. However, to prevent graft rejection or loss, lifelong immunosuppression is required. Tacrolimus is currently the cornerstone of post-transplantation immunosuppression. The study aim was to carry out an economic evaluation of immunosuppression, including more recent agents such as a once-daily prolonged-release formulation of tacrolimus (Advagraf™) and belatacept, relative to a twice-daily immediate-release formulation of tacrolimus (Prograf™).

METHODS

A MODEL WAS CONSTRUCTED COMPRISING SIX STATES: onset of biopsy-confirmed acute rejection, functioning graft with or without a biopsy-confirmed acute rejection, non-functioning graft (dialysis), re-transplantation, and death. Data on clinical effectiveness were derived from a systematic literature review and the model captured the effects of patient adherence to immunosuppressant therapy on graft survival using relative risk of graft survival and published data on adherence in patients using Advagraf and Prograf. In the base case, the time horizon was 25 years and one-way and probabilistic sensitivity analyses were conducted.

RESULTS

The analysis demonstrated that Prograf was cost-effective when compared with cyclosporin and belatacept and was more effective than sirolimus, but would not be considered cost-effective against sirolimus. The modeled improvement in the adherence profile of patients using Advagraf relative to Prograf resulted in both improved clinical outcomes and reduced costs.

CONCLUSION

Prograf was more clinically effective than cyclosporin, belatacept, and sirolimus, supporting its current positioning as the mainstay of immunosuppressive therapy in renal transplant recipients. Based on improved patient adherence with Advagraf, the model projected that Advagraf would be both more effective and less costly than Prograf. Replacing Prograf with Advagraf as the standard of care for post-transplant immunosuppression could likely result in both cost savings and improved clinical outcomes.