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)

Medication adherence interventions in transplantation lack information on how to implement findings from randomized controlled trials in real-world settings: A systematic review

BACKGROUND

Growing numbers of randomized controlled trials (RCTs) are showing the effectiveness of interventions to improve medication adherence in transplantation recipients. However, real-world implementation is still a major challenge. This systematic review assesses the range of information available in RCTs supporting these interventions' clinical adoption in adult transplant populations.

METHODS

We included RCTs of interventions that a) targeted any phase of medication adherence in solid organ or allogeneic stem cell transplantation recipients and b) were published between January 2015 and November 2020. We excluded study protocols, conference abstracts and studies focusing only on pediatric populations. We identified relevant database and trial registries as well as traced references backward and citations forward. Implementation-relevant information was evaluated using adapted versions of Peters' ten criteria: 1. healthcare/organizational context; 2. social/economic/policy context; 3. patient involvement; 4. other stakeholder involvement; 5. sample representativeness; 6. trial conducted in a real-world-setting; 7. presence of feasibility study; 8. implementation strategy; 9. process evaluation; 10. implementation outcomes, using a stoplight color-rating system.

RESULTS

Screening 17'004 titles/abstracts resulted in 23 eligible RCTs, including 2'339 patients (n = 19-209/study). All included studies focused on the implementation phase of medication adherence. The best-reported criteria were feasibility study (43%), representative sample (17%) and conducted in a real-world-setting (17%). Least reported were context (9%), implementation strategies (4%), process evaluation (4%).

CONCLUSIONS

RCTs testing medication adherence interventions tend to report limited implementation-relevant information. This hinders their translation to real-world transplant settings. Integrating implementation science principles early in the conceptualization of RCTs would fuel real-world-translation, reducing research waste.

Impact of Once- Versus Twice-Daily Tacrolimus Dosing on Medication Adherence in Stable Renal Transplant Recipients: A Canadian Single-Center Randomized Controlled Trial

Background:

Prevalence of immunosuppressant nonadherence in renal transplant recipients is high despite negative clinical outcomes associated with nonadherence. Simplification of dosing has been demonstrated to improve adherence in renal transplant recipients as measured through electronic monitoring and self-report.

Objective:

The purpose of this study was to replicate and extend previous findings by measuring adherence with multiple methods in a Canadian sample.

Design:

The study design was a randomized controlled medication dosing trial in adult renal transplant patients. The trial length was 4 months.

Setting:

This study was conducted within the Solid Organ Transplant (SOT) Clinic at Vancouver General Hospital (VGH; Vancouver, Canada).

Patients:

A total of 46 adult renal recipients (at least 1 year post-transplant) were recruited through the SOT clinic. With 8 withdrawals, 38 individuals completed all phases of the study.

Measurements:

Medication adherence was measured for a period of 4 months using multiple methods, including electronic monitoring (MEMS [Medication Event Monitoring System]), pharmacy refill data (medication possession ratio [MPR]), and by self-report using the Adherence subscale of the Transplant Effects Questionnaire (TEQ).

Methods:

Participants were randomized to twice-daily (n = 19) or once-daily tacrolimus dosing (n = 19) and followed over a 4-month period via monthly clinic study visits. Comparisons between the treatment groups were performed using the Mann-Whitney U and chi-square tests, for continuous and categorical variables, respectively.

Results:

As outlined in Table 3, the once-daily dosing group showed significantly better MEMS Dose Adherence (P = .001), whereas MEMS Timing Adherence showed a tendency toward better adherence for this group, but was not significant (P = .052). MEMS Days Adherent (P = .418), MPR% (P = .123), and self-reported adherence (P = .284) did not differ between the once- and twice-daily dosing groups when measured as continuous variables. The MPR% was significantly better for the once-daily dosing group when measured dichotomously but not continuously (P = .044). Notably, most of those exposed to once-daily dosing (63.2%) preferred this to the twice-daily regimen.

Limitations:

Limitations included small sample size and short follow-up period, precluding the examination of clinical outcome differences.

Conclusions:

Results for dose adherence replicate the finding that dose simplification increases adherence to immunosuppressants as measured through electronic monitoring. Such an advantage for the once-daily dosing group was not seen across the 2 other electronic monitoring measurement variables (days and timing adherence). This study extends previous research by examining adherence in once versus twice-daily dosing via prescription refill data in a Canadian sample. Given the gravity of potential health outcomes associated with nonadherence, although results indicate inconsistencies in significance testing across measurement methods, the medium to large effect sizes seen in the data favoring better adherence with once-daily dosing provide an indication of the potential clinical significance of these findings.

Trial registration:

This study was registered with ClinicalTrials.gov (NCT01334333) on April 11, 2011.

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.

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.