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

Characterizing the Use of Prolonged-Release Once-Daily Tacrolimus (LCPT) across Canada

Background

Tacrolimus is the most common calcineurin inhibitor given to kidney and liver transplant recipients. Prolonged-release once-daily tacrolimus (LCPT) is the newest formulation of this drug, but prescribing practices for tacrolimus across Canada are unknown.

Objectives

To investigate the use of tacrolimus across Canada, by determining coverage for the drug, exploring prescribing practices and factors related to decision-making, and identifying management methods for patients with rapid metabolism of tacrolimus.

Methods

A mixed-methods, descriptive study using survey-based data collection and qualitative interviews was undertaken. The medical director and a pharmacist from each adult kidney and liver transplant centre in Canada were invited to complete an electronic questionnaire consisting of 8 open-ended questions concerning their respective transplant programs' coverage for and use of tacrolimus. Interested participants completed a one-on-one virtual follow-up interview to explore experiences.

Results

A total of 28 health care providers participated in the survey, of whom 18 completed an interview, achieving representation from 15 (79%) of 19 kidney transplant programs and 3 (38%) of 8 liver transplant programs. Prescribing habits varied, with immediate-release tacrolimus (IR-Tac) being the most commonly preferred formulation (due to provider experience), followed by extended-release tacrolimus (ER-Tac) and LCPT. Most survey respondents (26/28) indicated that their centres used LCPT for maintenance but not de novo immunosuppression. The most common reason for conversion to LCPT was to reduce tremors or to address suspected rapid metabolism; barriers to uptake of LCPT included perceived disadvantages related to cost and coverage.

Conclusions

Prescribing practices for tacrolimus varied across Canada. IR-Tac was the most commonly used formulation, followed by ER-Tac. LCPT was used primarily in the maintenance phase for people with neurotoxicity or rapid metabolism, but there was a lack of consistency in how rapid metabolism was defined.

Efficacy of the Once-Daily Tacrolimus Formulation LCPT Compared to the Immediate-Release Formulation in Preventing Early Post-Transplant Diabetes in High-Risk Kidney Transplant Patients: A Randomized, Controlled, Open-Label Pilot Study (EUDRACT: 2017-000718-52)

Background/Objectives: Post-transplant diabetes mellitus (PTDM) and prediabetes (PreDM) are common after renal transplantation and increase the risk of cardiovascular events and mortality. Compared to immediate-release tacrolimus (IR-Tac), the LCPT formulation, with delayed absorption, offers higher bioavailability and a smoother time-concentration curve, potentially reducing beta-cell stress. Methods: This randomized pilot trial compared de novo immunosuppression with IR-Tac (twice daily) and LCPT (once daily). At-risk recipients (age ≥ 60 years or 18-59 years with metabolic syndrome) were enrolled and followed for 3 months. The primary and secondary outcomes were the incidence of PTDM and PreDM, respectively. Results: 27 patients were randomized to IR-Tac and 25 to LCPT. The incidence of PTDM was comparable between groups [IR Tac: 18.5% (95% CI: 8.2-36.7%) vs. LCPT: 24% (95% CI: 11.5-43.4%); p = 0.7]. Although not statistically significant, the LCPT group exhibited a trend toward a reduction in PreDM incidence [IR-Tac: 40.7% (95% CI: 25-59%) vs. LCPT: 20% (95% CI: 9-39%); p = 0.1]. A sensitivity analysis showed similar results, with no significant differences in cumulative corticosteroid doses or baseline body mass index (BMI) between groups. The LCPT group showed a trend toward higher tacrolimus exposure at the end of the study [trough levels: IR-Tac group 8.3 (6.9-9.2) vs. LCPT group 9.4 (7.4-11.4) ng/mL; p = 0.05)], as well as fewer acute rejection episodes (none vs. three). Delayed graft function was more common in the IR-Tac group (37% vs. 8%; p = 0.01), and the eGFR was lower. Adverse events were comparable between groups. Conclusions: The potential biological activity of LCPT in preventing glucose metabolic alterations in at-risk patients warrants further investigation.

Effects of switching from twice-daily tacrolimus to once-daily extended-release meltdose tacrolimus on cellular immune response

Background

LCP-Tacro [LCPT], a novel once-daily, extended-release formulation of tacrolimus, has a reduced Cmax with comparable AUC exposure, requiring a ∼30% dose reduction in contrast to immediate-release tacrolimus (IR-Tac). Once-daily LCPT in de novo kidney transplantation has a comparable efficacy and safety profile to that of IR-Tac with advantages in bioavailability and absorption. The present investigation intends to analyze the effects of conversion from IR-Tac to LCPT on phenotype and function of T-cells and B-cells.

Methods

16 kidney transplant patients treated by triple standard immunosuppression with a stable graft function undergoing a switch from IR-Tac to LCPT were included in this observational prospective study. We measured the main immune cell types and performed an in-depth characterization of B cell, dendritic cells and T cells including regulatory T cells of the patients before, 4 and 8 weeks after IR-Tac to LCPT conversion using multi-parameter fl ow cytometry. Additionally, we analyzed T cells by assessing third-party antigens (Tetanus Diphtheria, TD)-reactive T cells, which could be analyzed by restimulation with tetanus vaccine.

Results

Overall, we found no significant alterations following LCPT conversion for the most immune cell populations with a few cell populations showing transient quantitative increase. Thus, 4 weeks after conversion, more regulatory T cells could be measured in the patients with a significant shift from memory to naïve Tregs. Furthermore, we found a transient B cell expansion 4 weeks after conversion from IR-Tac to LCPT. There were no changes in the percentage of other basic immune cell types and the antigen-reactive T cells were also not altered after changing the medication to LCP-tacrolimus.

Conclusion

Here, we demonstrate first insights into the immune system changes occurred under IR-Tac to LCPT conversion therapy in kidney transplant patients. While phenotypic and functional characteristics of the most immune cell populations did not change, we could observe an a transient expansion of regulatory T cells in peripheral blood following IR-Tac to LCTP conversion, which might additionally contribute to the overall immunosuppressive effect.

Impact of Switching From Immediate- or Prolonged-Release to Once-Daily Extended-Release Tacrolimus (LCPT) on Tremor in Stable Kidney Transplant Recipients: The Observational ELIT Study

Once-daily extended-release tacrolimus (LCPT) exhibits increased bioavailability versus immediate-release (IR-TAC) and prolonged release (PR-TAC) tacrolimus. Improvements in tremor were previously reported in a limited number of kidney transplant patients who switched to LCPT. We conducted a non-interventional, non-randomized, uncontrolled, longitudinal, prospective, multicenter study to assess the impact of switching to LCPT on tremor and quality of life (QoL) in a larger population of stable kidney transplant patients. The primary endpoint was change in The Essential Tremor Rating Assessment Scale (TETRAS) score; secondary endpoints included 12-item Short Form Survey (SF-12) scores, tacrolimus trough concentrations, neurologic symptoms, and safety assessments. Subgroup analyses were conducted to assess change in TETRAS score and tacrolimus trough concentration/dose (C0/D) ratio by prior tacrolimus formulation and tacrolimus metabolizer status. Among 221 patients, the mean decrease of TETRAS score after switch to LCPT was statistically significant (p < 0.0001 vs. baseline). There was no statistically significant difference in change in TETRAS score after switch to LCPT between patients who had received IR-TAC and those who had received PR-TAC before switch, or between fast and slow metabolizers of tacrolimus. The overall increase of C0/D ratio post-switch to LCPT was statistically significant (p < 0.0001) and from baseline to either M1 or M3 (both p < 0.0001) in the mITT population and in all subgroups. In the fast metabolizers group, the C0/D ratio crossed over the threshold of 1.05 ng/mL/mg after the switch to LCPT. Other neurologic symptoms tended to improve, and the SF-12 mental component summary score improved significantly. No new safety concerns were evident. In this observational study, all patients had a significant improvement of tremor, QoL and C0/D ratio post-switch to LCPT irrespective of the previous tacrolimus formulation administered (IR-TAC or PR-TAC) and irrespective from their metabolism status (fast or slow metabolizers).

Three-year outcomes of de novo tacrolimus extended-release tablets (LCPT) compared to twice-daily tacrolimus in adult heart transplantation

BACKGROUND

Extended-release tacrolimus for prophylaxis of allograft rejection in heart transplant (HT) recipients is currently not FDA-approved. One such extended-release formulation of tacrolimus known as LCPT allows once-daily dosing and improves bioavailability compared to immediate-release (IR-) tacrolimus. We compared long-term efficacy and safety of LCPT to IR-tacrolimus applied de novo in adult OHT recipients.

METHODS

25 prospective recipients on LCPT at our center from 2017 to 2019 were matched 1:2 with historical control recipients treated with IR-tacrolimus based on age, gender, and baseline creatinine. The primary composite outcome of death, acute cellular rejection, and/or new graft dysfunction within 3 years following transplant was compared between groups using non-inferiority analysis.

RESULTS

LCPT demonstrated non-inferiority to IR-tacrolimus, with a primary outcome risk reduction of 16% (90%CI, -37%, -1%, non-inferiority p = 0.002) up to 3 years following heart transplant. Up to 3-years post-transplant, 14 patients remained on once-daily LCPT and 10 patients were switched to IR-tacrolimus due to lack of insurance coverage. There were no significant differences in the rate of chronic kidney disease requiring dialysis, cytomegalovirus requiring treatment, cardiac allograft vasculopathy, and malignancy within 3 years following transplant.

CONCLUSION

LCPT is non-inferior in efficacy to IR-tacrolimus in heart transplantation with a similar safety profile. Narrowly-constrained FDA labels specific to kidney transplant remain a barrier to consistent access to many immunosuppressant medications for recipients of non-kidney solid organs. We recommend the FDA consider developing facile pathways for expanding the approved label of extended-release tacrolimus formulations to heart transplant recipients.

Early outcomes associated with de novo once-daily extended-release versus twice-daily immediate-release tacrolimus in a predominantly African American kidney transplant population: A single-center observational study

INTRODUCTION

The purpose of this study was to compare early outcomes of de novo LCPT (once-daily extended-release tacrolimus) to IR TAC (twice-daily immediate-release tacrolimus) in a predominantly African American (AA) adult kidney transplant population.

METHODS

This is a single center, retrospective cohort study. Patients were divided into two cohorts: IR TAC (administered between January 1, 2017, and January 31, 2019) and LCPT (administered between February 1, 2019, and May 31, 2020). Primary endpoints were changes in tacrolimus trough levels (ng/mL) and estimated glomerular filtration rate up to 12 months post-transplantation. Clinical endpoints included graft survival, delayed graft function, biopsy-proven rejection, CMV viremia, and BK. A propensity score weighted generalized linear mixed effects model was used for analysis.

RESULTS

The rate of change in tacrolimus levels was significantly higher in the LCPT cohort compared to the IR TAC cohort at 14 days post-discharge (.2455 ng/mL per day vs. .1073 ng/mL, respectively; p < .001). Subsequently, the LCPT cohort had a slightly higher rate of decline (-.015 ng/mL per day vs. -.010 ng/mL with IR TAC; p = .0894) up to 12 months post-discharge. Although eGFR was similar between the two cohorts at 12 months post-transplant, the rate of increase was slower in the LCPT cohort (.1371 mL/min per day vs. .1852 mL/min per day, p = .0314). No significant differences were found in graft survival, DGF, BPAR, CMV, or BK infection.

CONCLUSION

This study demonstrates that despite higher early trough levels with immediate post-transplant LCPT use, clinical outcomes are comparable to IR TAC at one-year post-transplant. Notably, LCPT use does not increase the incidence of DGF and that this formulation of CNI can be used as first line therapy post-transplant.

Comparison of a novel tablet formulation of tacrolimus and conventional capsule formulation in de novo kidney transplant recipients: a systematic review and meta-analysis

Background: The work aimed to compare the pharmacokinetic (PK) profiles and other outcomes reported in observational studies in de novo kidney transplant recipients (KTRs) receiving novel once-daily extended-release tablet tacrolimus (LCPT; LCP-tacrolimus; Envarsus XR) or receiving standard-of-care capsule tacrolimus (PR-Tac; prolonged-release tacrolimus; Advagraf/IR-Tac; immediate-release tacrolimus; Prograf). Methods: A systematic review was conducted for all randomized controlled trials (RCTs) and cohort studies investigating the outcomes in KTRs receiving LCPT or PR-Tac/IR-Tac. We systematically searched PubMed, Web of Science, and EMBASE, with no language restriction. The registered trials and references listed in relevant studies were also searched. Data were extracted for the PK profile, tacrolimus trough level (TTL), and changes in the estimated glomerular filtration rate (eGFR) and serum creatinine (Scr), biopsy-proven acute rejection (BPAR) rate, delayed graft function (DGF) rate, post-transplant diabetes mellitus (PTDM) rate, tremor rate (TR), death rate (DR), and rate of infection by cytomegalovirus (CMV). This study was registered with PROSPERO (registration number: CRD42023403787). Results: A total of seven eligible articles including 1,428 patients with 712 in the LCPT group versus 716 in the PR-Tac/IR-Tac group were included in this study for evidence synthesis. The baseline characteristics of the LCPT, PR-Tac, and IR-Tac groups were similar. The pooled analysis showed a higher PK profile in the LCPT group, and this result was consistent with those of all the included studies. In addition, no significant difference was observed for other outcomes. Conclusion: Considering heterogeneity between studies and potential bias, care providers should select agents based on patient-specific factors and their clinical experience for the immunosuppressive treatment of de novo KTRs.

Tremor Induced by Cyclosporine, Tacrolimus, Sirolimus, or Everolimus: A Review of the Literature

Calcineurin inhibitors such as cyclosporine and tacrolimus are immunosuppressant drugs that are known to induce tremors. Non-calcineurin inhibitors such as sirolimus and everolimus have also reportedly been accompanied by tremors, albeit less likely. However, the prevalence rates reported in the literature are notably wide, and the risk profiles for these drug-induced tremors are less understood. We searched PubMed to extract data on the risk of tremors with these drugs when prescribed for various transplant and non-transplant indications. We ascertained whether the risk of drug-induced tremor is influenced by the underlying diagnosis, dosing formulations, drug concentrations, and blood monitoring. We extracted data on treatment strategies and outcomes for tremors. Articles were primarily screened based on English language publications, abstracts, and studies with n ≥ 5, which included case series, retrospective studies, case-controlled studies, and prospective studies. We found 81 eligible studies comprising 33 cyclosporine, 43 tacrolimus, 6 sirolimus, and 1 everolimus that discussed tremor as an adverse event. In the pooled analysis of studies with n > 100, the incidence of tremor was 17% with cyclosporine, 21.5% with tacrolimus, and 7.8% with sirolimus and everolimus together. Regarding the underlying diagnosis, tremor was more frequently reported in kidney transplant (cyclosporine 28%, tacrolimus 30.1%) and bone marrow transplant (cyclosporine 40%, tacrolimus 41.9%) patients compared with liver transplant (cyclosporine 9%, tacrolimus 11.5%) and nontransplant indications (cyclosporine 21.5%, tacrolimus 11.3%). Most studies did not report whether the risk of tremors correlated with drug concentrations in the blood. The prevalence of tremors when using the twice-daily formulation of tacrolimus was nearly the same as the once-daily formulation (17% vs 18%). Data on individual-level risk factors for tremors were lacking. Except for three studies that found some benefit to maintaining magnesium levels, there were minimal data on treatments and outcomes. A large body of data supports a substantive and wide prevalence of tremor resulting from tacrolimus use followed by cyclosporine, especially in patients receiving a kidney transplant. However, there is little reporting on the patient-related risk factors for tremor, risk relationship with drug concentrations, treatment strategies, and outcomes.

Review of industrially recognized polymers and manufacturing processes for amorphous solid dispersion based formulations

Evolving therapeutic landscape through combinatorial chemistry and high throughput screening have resulted in an increased number of poorly soluble drugs. Drug delivery strategies quickly adapted to convert these drugs into successful therapies. Amorphous solid dispersion (ASD) technology is widely employed as a drug delivery strategy by pharmaceutical industries to overcome the challenges associated with these poorly soluble drugs. The development of ASD formulation requires an understanding of polymers and manufacturing techniques. A review of US FDA-approved ASD-based products revealed that only a limited number of polymers and manufacturing technologies are employed by pharmaceutical industries. This review provides a comprehensive guide for the selection and overview of polymers and manufacturing technologies adopted by pharmaceutical industries for ASD formulation. The various employed polymers with their underlying mechanisms for solution-state and solid-state stability are discussed. ASD manufacturing techniques, primarily implemented by pharmaceutical industries for commercialization, are presented in Quality by Design (QbD) format. An overview of novel excipients and progress in manufacturing technologies are also discussed. This review provides insights to the researchers on the industrially accepted polymers and manufacturing technology for ASD formulation that has translated these challenging drugs into successful therapies.

A comprehensive update of the metabolic and toxicological considerations for immunosuppressive drugs used during pancreas transplantation

INTRODUCTION

Despite significant advancements in immunosuppressive regimens and surgical techniques, the prevalence of adverse events related to immunosuppression remains a major challenge affecting the long-term survival rates of pancreas and kidney allografts.

AREAS COVERED

This article presents a comprehensive review of the literature and knowledge (Jan/2012-Feb/2023) concerning glucose metabolism disorders and nephrotoxicity associated with tacrolimus and mammalian target of rapamycin inhibitors (mTORi). Novel signaling pathways potentially implicated in these adverse events are discussed. Furthermore, we extensively examine the findings from clinical trials evaluating the efficacy and safety of tacrolimus, mTORi, and steroid minimization.

EXPERT OPINION

Tacrolimus-based regimens continue to be the standard treatment following pancreas transplants. However, prolonged use of tacrolimus and mTORi may lead to hyperglycemia and nephrotoxicity. Understanding and interpreting experimental data, particularly concerning novel signaling pathways beyond calcineurin-NFAT and mTOR pathways, can offer valuable insights for therapeutic interventions to mitigate hyperglycemia and nephrotoxicity. Additionally, critically analyzing clinical trial results can identify opportunities for personalized safety-based approaches to minimize side effects. It is imperative to conduct randomized-controlled studies to assess the impact of mTORi use and steroid-free protocols on pancreatic allograft survival. Such studies will aid in tailoring treatment strategies for improved transplant outcomes.

Intestinal Permeability in Patients Early after Kidney Transplantation Treated with Two Different Formulations of Once-Daily Tacrolimus

Adequate tacrolimus blood exposure is crucial in the early post-renal transplant period and a gut epithelial barrier integrity may play a role. We prospectively investigated several markers of intestinal permeability in recent kidney transplant recipients (KTRs) treated with different tacrolimus extended-release formulations. Within each of the 49 KTR pairs that received grafts from the same donor, an early randomized conversion was performed from twice-daily (Prograf) to once-daily tacrolimus formulation: Advagraf or Envarsus. Plasma zonulin, calprotectin, circulating lipopolysaccharide (LPS), LPS-binding protein (LBP), intestinal fatty acid binding protein (FABP-2), and CD-14 levels were measured. There was no difference in the recipient age, dialysis vintage, BMI, and residual diuresis between Advagraf and Envarsus groups. FABP-2 and LPS levels were significantly associated with tacrolimus trough level, 3-h level, and area under the curve (AUC) in the Envarsus but not in the Advagraf group. AUC was independently increased by LPS and decreased by age, FABP-2 concentration, and the use of Envarsus formulation as compared with Advagraf. Functional changes of gastrointestinal tract in patients treated with Envarsus may influence intestinal tacrolimus absorption to a greater extent than in Advagraf-treated KTRs and may lead to inadequate variability of tacrolimus exposure early after kidney transplantation.

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

INTRODUCTION

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Chronic kidney disease after lung transplantation in a changing era

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

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

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

A randomized crossover study comparing different tacrolimus formulations to reduce intrapatient variability in tacrolimus exposure in kidney transplant recipients

A high intrapatient variability (IPV) in tacrolimus exposure is a risk factor for poor long‐term outcomes after kidney transplantation. The main objective of this trial was to investigate whether tacrolimus IPV decreases after switching patients from immediate‐release (IR)‐tacrolimus to either extended‐release (ER)‐tacrolimus or LifeCyclePharma (LCP)‐tacrolimus. In this randomized, prospective, open‐label, cross‐over trial, adult kidney transplant recipients on a stable immunosuppressive regimen, including IR‐tacrolimus, were randomized for conversion to ER‐tacrolimus or LCP‐tacrolimus, and for the order in which IR‐tacrolimus and the once‐daily formulations were taken. Patients were followed 6 months for each formulation, with monthly tacrolimus predose concentration assessments to calculate the IPV. The IPV was defined as the coefficient of variation (%) of dose corrected predose concentrations. Ninety‐two patients were included for analysis of the primary outcome. No significant differences between the IPV of IR‐tacrolimus (16.6%) and the combined once‐daily formulations (18.3%) were observed (% difference +1.7%, 95% confidence interval [CI] −1.1% to ‒4.5%, p = 0.24). The IPV of LCP‐tacrolimus (20.1%) was not significantly different from the IPV of ER‐tacrolimus (16.5%, % difference +3.6%, 95% CI −0.1% to 7.3%, p = 0.06). In conclusion, the IPV did not decrease after switching from IR‐tacrolimus to either ER‐tacrolimus or LCP‐tacrolimus. These results provide no arguments to switch kidney transplant recipients from twice‐daily (IR) tacrolimus formulations to once‐daily (modified‐release) tacrolimus formulations when the aim is to lower the IPV.

Bioavailability of once-daily tacrolimus formulations used in clinical practice in the management of De Novo kidney transplant recipients: the better study

Multicenter, prospective, observational study to compare the relative bioavailability of once‐daily tacrolimus formulations in de novo kidney transplant recipients. De novo kidney transplant recipients who started a tacrolimus‐based regimen were included 14 days post‐transplant and followed up for 6 months. Data from 218 participants were evaluated: 129 in the LCPT group (Envarsus) and 89 in the PR‐Tac (Advagraf) group. Patients in the LCPT group exhibited higher relative bioavailability (C_min /total daily dose [TDD]) vs. PR‐Tac (61% increase; P < .001) with similar C_min and 30% lower TDD levels (P < .0001). The incidence of treatment failure was 3.9% in the LCPT group and 9.0% in the PR‐Tac group (P = .117). Study discontinuation rates were 6.2% in the LCPT group and 12.4% in the PR‐Tac group (P = .113). Adverse events, renal function and other complications were comparable between groups. The median accumulated dose of tacrolimus in the LCPT group from day 14 to month 6 was 889 mg. Compared to PR‐Tac, LCPT showed higher relative bioavailability, similar effectiveness at preventing allograft rejection, comparable effect on renal function, safety, adherence, treatment failure and premature discontinuation rates.

De novo tacrolimus extended-release tablets (LCPT) versus twice-daily tacrolimus in adult heart transplantation: Results of a single-center non-inferiority matched control trial

Extended-release tacrolimus for prophylaxis of allograft rejection in orthotopic heart transplant (OHT) recipients is currently not FDA-approved. One such extended-release formulation of tacrolimus known as LCPT allows once-daily dosing and improves bioavailability compared to immediate-release tacrolimus (IR-tacrolimus). We compared the efficacy and safety of LCPT to IR-tacrolimus applied de novo in adult OHT recipients. Twenty-five prospective recipients on LCPT at our center from 2017 to 2019 were matched 1:2 with historical control recipients treated with IR-tacrolimus based on age, gender, and baseline creatinine. The primary composite outcome of death, acute cellular rejection, and/or new graft dysfunction within 1 year was compared using non-inferiority analysis. LCPT demonstrated non-inferiority to IR-tacrolimus, with a primary outcome risk reduction of 20% (90% CI: -40%, -.5%; non-inferiority P = .001). Tacrolimus trough levels peaked at 2-3 months and were higher in LCPT (median 14.5 vs. 12.7 ng/ml; P = .03) with similar dose levels (LCPT vs. IR-tacrolimus: .08 vs. .09 mg/kg/day; P = .33). Cardiovascular-related readmissions were reduced by 62% (P = .046) in LCPT patients. The complication rate per transplant admission and all-cause readmission rate did not differ significantly. These results suggest that LCPT is non-inferior in efficacy to IR-tacrolimus with a similar safety profile and improved bioavailability in OHT.

A single-center, open-label, randomized cross-over study to evaluate the pharmacokinetics and bioavailability of once-daily prolonged-release formulations of tacrolimus in de novo liver transplant recipients

BACKGROUND

The narrow therapeutic window of tacrolimus (Tac) requires intense drug monitoring to achieve adequate efficacy while minimizing dose-related toxicities. Once-daily formulations of Tac (LCP-Tac and PR-Tac) have been recently designed for higher bioavailability and a more consistent exposure over time, as opposed to the twice-daily, administered immediate-release formulation of Tac (IR-Tac).

METHODS

This single-center, open-label, randomized cross-over pharmacokinetic (PK) study compares extended-release LCP-Tac with the prolonged-release formulation of tacrolimus (PR-Tac) in adult de novo liver transplant recipients. Eligible patients were screened and randomized 1:1 to the two treatment arms up to 30 days after liver transplantation. Patients were administered either LCP-Tac or PR-Tac for 14 days followed by another 14-day time interval of the other once-daily Tac medication. A 24hr-PK profile was obtained at the end of each time interval.

RESULTS

Nine patients (45%) completed the study resulting in a total of 18 Tac PK profiles. Overall, the profile of the mean concentrations indicated a flattened kinetic of LCP-Tac compared to PR-Tac, especially in the first 3 h after drug intake. The average cumulative dose per day to achieve equivalent trough levels was approximately 25% lower for LCP-Tac (8.7 mg) than for PR-Tac (11.7 mg). LCP-Tac resulted in a longer tmax and fewer peak-to-trough fluctuations compared to PR-Tac.

CONCLUSION

Despite methodological weaknesses that limit the conclusions, we have found a more consistent drug exposure for LCP-Tac in de novo LT recipients. LCP-Tac demonstrated a greater bioavailability compared to PR-Tac.

Tacrolimus Intrapatient Variability After Switching From Immediate or Prolonged-Release to Extended-Release Formulation, After an Organ Transplantation

Background and Purpose: Several formulations of tacrolimus are available, but evidence of the benefit of changing to the most recent formulations is lacking. Tacrolimus intra-patient variability (tacrolimus IPV) is an emerging risk factor associated with poor graft outcomes after solid organ transplantations. Here, we examined the modifications of tacrolimus IPV after switching to a different formulation of tacrolimus. Experimental Approach: We identified 353 solid organ transplant recipients that were switched in our center from immediate-release (IR-tacrolimus) or prolonged-release tacrolimus (PR-tacrolimus) to extended-release, LCP-tacrolimus (LCP-tacrolimus). Among them, 54 patients underwent at least 3 available tacrolimus blood concentrations before and after the switch, allowing us to investigate tacrolimus IPV. Key Results: The switch was considered as a safe procedure since only four of the 353 patients presented a graft rejection after the switch, and no patient was hospitalized for tacrolimus overdose. The tacrolimus IPV estimated by the coefficient of variation (CV-IPV) was stable before and after the switch to LCP-tacrolimus (CV-IPV: 29.0% (IQR 25-75 (15.5; 38.5) before and 24.0% (15.8; 36.5) after the switch, p = 0.65). Conclusion and Implications: Switching from IR- or PR-tacrolimus to LCP-tacrolimus is a safe procedure. However, the CV-tacrolimus IPV was not impacted by the change of formulation.

Therapeutic Drug Monitoring Strategies for Envarsus in De Novo Kidney Transplant Patients Using Population Modelling and Simulations

INTRODUCTION

Tacrolimus, the cornerstone of transplantation immunosuppression, is a narrow therapeutic index drug with a low and highly variable bioavailability. Therapeutic drug monitoring based on trough level assessment is mandatory in order to target a personalised exposure and avoid both rejection and toxicity. Population pharmacokinetic (POPPK) models might be a useful tool for improving early attainment of target range by guiding initial doses until steady state is reached and trough levels can be reliably used as surrogate marker of exposure. Here we present the first POPPK for predicting the initial doses of the once-daily prolonged release tacrolimus Envarsus (LCPT) in adult kidney recipients.

METHODS

The model was developed exploiting the data from a recent pharmacokinetic randomised clinical study, in which 69 de novo kidney recipients, 33 of whom treated with LCPT, underwent an intensive blood sampling strategy for tacrolimus including four complete pharmacokinetic profiles.

RESULTS

The complex and prolonged absorption of LCPT is well described by the three-phase model that incorporates body weight and CYP3A5 genotype as significant covariates accounting for a great proportion of the inter-patient variability: in particular, CYP3A5*1/*3 expressors had a 66% higher LCPT clearance. We have then generated by simulation a personalised dosing strategy based on the model that could improve the early attainment of therapeutic trough levels by almost doubling the proportion of patients within target range (69.3% compared to 36.1% with the standard body weight-based approach) on post-transplantation day 4 and significantly reduce the proportion of overexposed patients at risk of toxicity.

CONCLUSIONS

A POPPK model was successfully developed for LCPT in de novo kidney recipients. The model could guide a personalised dosing strategy early after transplantation. For the model to be translated into clinical practice, its beneficial impact of earlier attainment of therapeutic trough levels should be demonstrated on hard clinical outcomes in further studies.

Efficacy and Safety of Once-Daily LCP-Tacrolimus Versus Twice-Daily Immediate-Release Tacrolimus in Adult Hispanic Stable Kidney Transplant Recipients: Sub-Group Analysis from a Phase 3 Trial

BACKGROUND The pharmacokinetics and metabolism of tacrolimus, an immunosuppressant commonly used to prevent transplant rejection, can differ in specific subpopulations. This analysis examined treatment outcomes and safety of immediate-release tacrolimus (IR-Tac) and LCP-tacrolimus (LCPT) in stable Hispanic kidney transplant recipients. MATERIAL AND METHODS This was a post hoc analysis of clinical trial data from Hispanic adult stable kidney transplant recipients randomized to remain on IR-Tac or convert from IR-Tac to a reduced dose of LCPT (NCT00817206). Composite treatment failure was evaluated at 12 months. Estimated glomerular filtration rate and tacrolimus trough concentrations were evaluated over 12 months. RESULTS Fifty-five stable (LCPT n=26, IR-Tac n=29) kidney transplant recipients who self-identified as Hispanic or Latino were included in this analysis. Composite treatment failure occurred in 1 patient (4%) who converted to LCPT and 1 (3%) who remained on IR-Tac. The estimated glomerular filtration rate was stable over time and similar in the 2 treatment groups (P=0.08). Tacrolimus trough levels for both groups were similar over time in the 2 treatment groups (P=0.98). Treatment-emergent adverse events were similar in patients who converted to LCPT and in those who remained on IR-Tac. CONCLUSIONS Efficacy and safety were similar in Hispanic kidney transplant recipients who converted from IR-Tac to LCPT and in those remaining on IR-Tac.

Population pharmacokinetics and genetics of oral meltdose tacrolimus (Envarsus) in stable adult liver transplant recipients

AIMS

Meltdose tacrolimus (Envarsus) is marketed as a formulation with a more consistent exposure. Due to the narrow therapeutic window, therapeutic drug monitoring is essential to maintain adequate exposure. The primary objective of this study was to develop a population pharmacokinetic (PK) model of Envarsus among liver transplant patients and select a limited sampling strategy (LSS) for AUC estimation. The secondary objective was to investigate potential covariates including CYP3A/IL genotype suitable for initial dose optimization when converting to Envarsus.

METHODS

Adult liver transplant patients were converted from prolonged release tacrolimus (Advagraf) to Envarsus and blood samples were obtained using whole blood and dried blood spot sampling. Subsequently the population PK parameters were estimated using nonlinear-mixed effect modelling. Demographic factors, and recipient and donor CYP3A4, CYP3A5, IL-6, -10 and -18 genotype were tested as potential covariates to explain interindividual variability.

RESULTS

Fifty-five patients were included. A 2-compartment model with delayed absorption was the most suitable to describe population PK parameters. The population PK parameters were as follows: clearance, 3.27 L/h; intercompartmental clearance, 9.6 L/h; volume of distribution of compartments 1 and 2, 95 and 500 L, respectively. No covariates were found to significantly decrease interindividual variability. The best 3-point LSS was t = 0,4,8 with a median bias of 1.8% (-12.5-12.5).

CONCLUSIONS

The LSS can be used to adequately predict the AUC. No clinically relevant covariates known to influence the PK of Envarsus, including CYP3A status, were identified and therefore do not seem useful for initial dose optimization.

Real-World Administration of Once-Daily MeltDose® Prolonged-Release Tacrolimus (LCPT) Allows for Dose Reduction of Tacrolimus and Stabilizes Graft Function Following Liver Transplantation

The calcineurin inhibitor tacrolimus is included in most immunosuppressive protocols after liver transplantation. This retrospective, observational 24-month study investigated the tolerability of once-daily MeltDose^® prolonged-release tacrolimus (LCPT) after switching from twice-daily immediate-release tacrolimus (IR-Tac) in a real-world cohort of 150 patients with previous liver transplantation. No graft rejection or new safety signals were observed. Only 7.3% of patients discontinued LCPT due to side effects. In the overall patient population, median liver transaminases, total cholesterol, triglycerides, glucose, and HbA_1c remained constant after switching to LCPT. Total cholesterol significantly decreased (p ≤ 0.002) in patients with initially elevated levels (>200 mg/dL). A total of 71.8% of 96 patients maintained a glomerular filtration rate > 60 mL/min/1.73 m² throughout the study, while 44.7% of patients were classified as fast metabolizers and 55.3% as slow metabolizers. Median daily tacrolimus dose could be reduced by 50% in fast metabolizers and by 30% in slow metabolizers, while trough levels were maintained in the target range (4–6 ng/mL). In conclusion, our observational study confirmed previous evidence of good overall tolerability and a favorable outcome for the patients after switching from IR-Tac to LCPT after liver transplantation.

Predictors of tacrolimus pharmacokinetic variability: current evidences and future perspectives

INTRODUCTION

In kidney transplantation, tacrolimus (TAC) is at the cornerstone of current immunosuppressive strategies. Though because of its narrow therapeutic index, it is critical to ensure that TAC levels are maintained within this sharp window through reactive adjustments. This would allow maximizing efficiency while limiting drug-associated toxicity. However, TAC high intra- and inter-patient pharmacokinetic (PK) variability makes it more laborious to accurately predict the appropriate dosage required for a given patient.

AREAS COVERED

This review summarizes the state-of-the-art knowledge regarding drug interactions, demographic and pharmacogenetics factors as predictors of TAC PK. We provide a scoring index for each association to grade its relevance and we present practical recommendations, when possible for clinical practice.

EXPERT OPINION

The management of TAC concentration in transplanted kidney patients is as critical as it is challenging. Recommendations based on rigorous scientific evidences are lacking as knowledge of potential predictors remains limited outside of DDIs. Awareness of these limitations should pave the way for studies looking at demographic and pharmacogenetic factors as well as gut microbiota composition in order to promote tailored treatment plans. Therapeutic approaches considering patients' clinical singularities may help allowing to maintain appropriate concentration of TAC.

Effect of Concentration/Dose Ratio in De Novo Kidney Transplant Recipients Receiving LCP-Tacrolimus or Immediate-Release Tacrolimus: Post Hoc Analysis of a Phase 3 Clinical Trial

Background

A previous phase 3 clinical trial in de novo adult kidney transplant recipients (NCT01187953) compared the efficacy and safety of once-daily LCP-tacrolimus (LCPT) and twice-daily immediate-release tacrolimus (IR-Tac). However, whether the rate of tacrolimus metabolism affects outcomes between LCPT and IR-Tac was not examined.

Material/Methods

Patients were initiated on 0.17 mg/kg/day LCPT or 0.1 mg/kg/day IR-Tac, with doses adjusted over time to maintain target therapeutic trough concentrations. This post hoc analysis examined dosing trends, relative efficacy, and safety of LCPT (n=247) and IR-Tac (n=249) in slow, intermediate, and rapid metabolizers as defined by concentration/dose ratios at day 30.

Results

For all metabolizer subgroups, minimum target tacrolimus trough concentrations were obtained more rapidly with LCPT than with IR-Tac. Slow metabolizers were more likely to exceed target trough concentrations with LCPT, while rapid metabolizers were more likely to fall below target trough concentrations with IR-Tac. Regardless of metabolizer status, significant differences were not detected between LCPT and IR-Tac for treatment failure, death, graft failure, biopsy-proven acute rejection, estimated glomerular filtration rate, or other clinical outcomes.

Conclusions

Although within metabolizer subgroups, attainment of target trough concentrations in the first week differed between LCPT and IR-Tac, these results suggest that, regardless of metabolizer phenotype, clinical outcomes do not differ between these formulations when dose adjustments are made.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT01187953

Conversion from Standard-Release Tacrolimus to MeltDose® Tacrolimus (LCPT) Improves Renal Function after Liver Transplantation

Renal impairment is a typical side effect of tacrolimus (Tac) treatment in liver transplant (LT) recipients. One strategy to avoid renal dysfunction is to increase the concentration/dose (C/D) ratio by improving drug bioavailability. LT recipients converted from standard-release Tac to MeltDose^® Tac (LCPT), a novel technological formulation, were able to reduce the required Tac dose due to higher bioavailability. Hence, we hypothesize that such a conversion increases the C/D ratio, resulting in a preservation of renal function. In the intervention group, patients were switched from standard-release Tac to LCPT. Clinical data were collected for 12 months after conversion. Patients maintained on standard-release Tac were enrolled as a control group. Twelve months after conversion to LCPT, median C/D ratio had increased significantly by 50% (p < 0.001), with the first significant increase seen 3 months after conversion (p = 0.008). In contrast, C/D ratio in the control group was unchanged after 12 months (1.75 vs. 1.76; p = 0.847). Estimated glomerular filtration rate (eGFR) had already significantly deteriorated in the control group at 9 months (65.6 vs. 70.6 mL/min/1.73 m² at study onset; p = 0.006). Notably, patients converted to LCPT already had significant recovery of mean eGFR 6 months after conversion (67.5 vs. 65.3 mL/min/1.73 m² at study onset; p = 0.029). In summary, conversion of LT recipients to LCPT increased C/D ratio associated with renal function improvement.

The use of LCP-Tacrolimus (Envarsus XR) in simultaneous pancreas and kidney (SPK) transplant recipients

BACKGROUND

Extended release LCP-tacrolimus (LCPT) allows once-daily dosing in transplant recipients. The improved bioavailability may be beneficial for simultaneous pancreas-kidney recipients (SPK).

METHODS

This is a study of 39 SPK recipients on standard immediate-release tacrolimus (IR-TAC, n = 21) or LCPT (n = 18). Coefficient of variability (CV = 100∗standard deviation/mean) was calculated to assess drug levels. Hemoglobin A1c (HbA1c), tacrolimus and creatinine levels were measured postoperatively.

RESULTS

There was no difference in tacrolimus CV in the IR-TAC and LCPT groups at 1 month or 3 months postoperatively; however, a greater difference was observed at 1 year (41.0 vs. 33.1%; p = 0.19). There were six episodes of acute rejection in the IR-TAC group compared to zero episodes in the LCPT group (p = 0.01). HbA1c was significantly higher in the IR-TAC group compared to LCPT at 3 (5.5 vs. 4.9%, p = 0.01), 6 (5.6 vs. 4.9%, p = 0.01) and 12 months (5.8 vs. 5.1%, p = 0.07).

CONCLUSIONS

Significantly lower rates of rejection were observed in patients receiving LCPT. The once daily dosing may facilitate medication adherence and result in improved long-term outcomes.

Effectiveness and safety of the conversion to MeltDose® extended-release tacrolimus from other formulations of tacrolimus in stable kidney transplant patients: A retrospective study

Tacrolimus is the cornerstone of immunosuppressive therapy after kidney transplantation. Its narrow therapeutic window mandates serum level strict monitoring and dose adjustments to ensure the optimal risk‐benefit balance. This observational retrospective study analyzed the effectiveness and safety of conversion from twice‐daily immediate‐release tacrolimus (IR‐Tac) or once‐daily prolonged‐release tacrolimus (PR‐Tac) to the recent formulation once‐daily MeltDose^® extended‐release tacrolimus (LCP‐Tac) in 365 stable kidney transplant recipients. We compared kidney function three months before and three months after the conversion. Three months after conversion, the total daily dose was reduced ~35% (P < .0001), and improved bioavailability and stable serum LCP‐Tac concentrations were observed. There was no increase in the number of patients requiring tacrolimus dose adjustments after conversion. Renal function was unaltered, and no cases of BPAR were reported. Reports of tremors, as collected in the clinical histories for each patient, decreased from pre‐conversion (20.8%) to post‐conversion (11.8%, P < .0001). LCP‐Tac generated a cost reduction of 63% compared with PR‐Tac. In conclusion, the conversion strategy to LCP‐Tac from other tacrolimus formulations in stable kidney transplant patients showed safety and effectiveness in a real‐world setting, confirming the data from RCTs. The specific pharmacokinetic properties of LCP‐Tac could be potentially advantageous in patients with tacrolimus‐related adverse events.