γ-Cyclodextrin hydrogel for the sustained release of josamycin for potential ocular application.

Glaucoma is the leading cause of blindness worldwide. However, its surgical treatment, in particular via trabeculectomy, can be complicated by fibrosis. In current clinical practice, application of the drug, Mitomycin C, prevents or delays fibrosis, but can lead to additional side effects, such as bleb leakage and hypotony. Previous in silico drug screening and in vitro testing has identified the known antibiotic, josamycin, as a possible alternative antifibrotic medication with potentially fewer side effects. However, a suitable ocular delivery mechanism for the hydrophobic drug to the surgical site does not yet exist. Therefore, the focus of this paper is the development of an implantable drug delivery system for sustained delivery of josamycin after glaucoma surgery based on crosslinked γ-cyclodextrin. γ-Cyclodextrin is a commonly used solubilizer which was shown to complex with josamycin, drastically increasing the drug's solubility in aqueous solutions. A simple γ-cyclodextrin crosslinking method produced biocompatible hydrogels well-suited for implantation. The crosslinked γ - cyclodextrin retained the ability to form complexes with josamycin, resulting in a 4-fold higher drug loading efficiency when compared to linear dextran hydrogels, and prolonged drug release over 4 days.

Long-term Prolonged-release Tacrolimus-based Immunosuppression in De Novo Kidney Transplant Recipients: 5-Y Prospective Follow-up of Patients in the ADVANCE Study.

Although prolonged-release tacrolimus (PR-T) is widely approved for posttransplantation immunosuppression in kidney recipients, large-scale studies are required to assess long-term outcomes. We present follow-up data from the Advagraf-based Immunosuppression Regimen Examining New Onset Diabetes Mellitus in Kidney Transplant Recipients (ADVANCE) trial, in which kidney transplant patients (KTPs) received corticosteroid minimization with PR-T. Methods: ADVANCE was a 24-wk, randomized, open-label, phase-4 study. De novo KTPs received PR-T with basiliximab and mycophenolate mofetil and were randomized to receive an intraoperative corticosteroid bolus plus tapered corticosteroids until day 10 (arm 1) or an intraoperative corticosteroid bolus (arm 2). In this 5-y, noninterventional follow-up, patients received maintenance immunosuppression according to standard practice. The primary endpoint was graft survival (Kaplan-Meier). Secondary endpoints included patient survival, biopsy-confirmed acute rejection-free survival, and estimated glomerular filtration rate (4-variable modification of diet in renal disease). Results: Follow-up study included 1125 patients. Overall graft survival at 1 and 5 y posttransplantation was 93.8% and 88.1%, respectively, and was similar between treatment arms. At 1 and 5 y, patient survival was 97.8% and 94.4%, respectively. Five-year graft and patient survival rates in KTPs who remained on PR-T were 91.5% and 98.2%, respectively. Cox proportional hazards analysis demonstrated similar risk of graft loss and death between treatment arms. Five-year biopsy-confirmed acute rejection-free survival was 84.1%. Mean ± standard deviation values of estimated glomerular filtration rate were 52.7 ± 19.5 and 51.1 ± 22.4 mL/min/1.73 m2 at 1 and 5 y, respectively. Fifty adverse drug reactions were recorded, probably tacrolimus-related in 12 patients (1.5%). Conclusions: Graft survival and patient survival (overall and for KTPs who remained on PR-T) were numerically high and similar between treatment arms at 5 y posttransplantation.

Long-term, Prolonged-release Tacrolimus-based Immunosuppression in De Novo Liver Transplant Recipients: 5-year Prospective Follow-up of Patients in the DIAMOND Study.

BACKGROUND: Immunosuppression with calcineurin inhibitors (CNIs) is reportedly associated with risk of renal impairment in liver transplant recipients. It is believed that this can be mitigated by decreasing initial exposure to CNIs or delaying CNI introduction until 3-4 d posttransplantation. The ADVAGRAF studied in combination with mycophenolate mofetil and basiliximab in liver transplantation (DIAMOND) trial evaluated different administration strategies for prolonged-release tacrolimus (PR-T). METHODS: DIAMOND was a 24-wk, open-label, phase 3b trial in de novo liver transplant recipients randomized to: PR-T 0.2 mg/kg/d (Arm 1); PR-T 0.15-0.175 mg/kg/d plus basiliximab (Arm 2); or PR-T 0.2 mg/kg/d delayed until day 5 posttransplant plus basiliximab (Arm 3). In a 5-y follow-up, patients were maintained on an immunosuppressive regimen according to standard clinical practice (NCT02057484). Primary endpoint: graft survival (Kaplan-Meier analysis). RESULTS: Follow-up study included 856 patients. Overall graft survival was 84.6% and 73.5% at 1 and 5 y post transplant, respectively. Five-year rates for Arms 1, 2, and 3 were 74.7%, 71.5%, and 74.5%, respectively. At 5 y, death-censored graft survival in the entire cohort was 74.7%. Overall graft survival in patients remaining on PR-T for ≥30 d was 79.1%. Graft survival in patients who remained on PR-T at 5 y was 87.3%. Patient survival was 86.6% at 1 y and 76.3% at 5 y, with survival rates similar in the 3 treatment arms at 5 y. Estimated glomerular filtration rate at the end of the 24-wk initial study and 5 y posttransplant was 62.1 and 61.5 mL/min/1.73 m2, respectively, and was similar between the 3 treatment arms at 5 y. Overall, 18 (2.9%) patients had ≥1 adverse drug reaction, considered possibly related to PR-T in 6 patients. CONCLUSIONS: In the DIAMOND study patient cohort, renal function, graft survival, and patient survival were similar between treatment arms at 5 y posttransplant.

Validation of a Capillary Dry Blood Sample MITRA-Based Assay for the Quantitative Determination of Systemic Tacrolimus Concentrations in Transplant Recipients.

BACKGROUND: Tacrolimus is a narrow therapeutic index medication, which requires therapeutic drug monitoring to optimize dosing based on systemic exposure. MITRA microsampling offers a convenient, minimally invasive approach for the collection of capillary blood samples from a finger prick versus conventional venous blood sampling for quantitation of tacrolimus blood concentrations. However, the suitability of MITRA microsampling for the determination of tacrolimus concentrations requires assessment in clinical settings. METHODS: Paired venous (2 mL) and capillary (10 µL) blood samples were collected pre-tacrolimus dose and 1 and 3 hours postdose during routine outpatient visits from stable adult liver or kidney transplant patients receiving prolonged-release tacrolimus. Tacrolimus concentrations were determined by liquid chromatography-tandem mass spectrometry, and the concentrations obtained by the 2 sampling methods were compared by linear regression and Bland-Altman agreement analyses. RESULTS: Samples were available for 82 transplant recipients (kidney, n = 41; liver, n = 41). A high correlation was observed between tacrolimus concentrations in capillary and venous blood samples (Pearson correlation coefficient, 0.97; Lin concordance coefficient, 0.87; slope of the fitted line, >1.0). Tacrolimus concentrations in capillary samples were 22.5% higher on average than in the corresponding venous blood samples (95% limits of agreement, 0.5%-44.6%). Similar results were observed in both transplant subgroups. CONCLUSIONS: MITRA finger prick sampling provides a convenient alternative to venipuncture for therapeutic drug monitoring in transplant recipients maintained on prolonged-release tacrolimus. When using the finger prick MITRA method, the positive bias in tacrolimus concentrations observed with this technique, when compared with venipuncture, needs to be taken into consideration.

Quantitation of Tacrolimus in Human Whole Blood Samples Using the MITRA Microsampling Device.

BACKGROUND: The calcineurin inhibitor tacrolimus is a narrow therapeutic index medication, which requires therapeutic drug monitoring to optimize dose on the basis of systemic exposure. MITRA microsampling offers a minimally invasive approach for the collection of capillary blood samples from a fingerprick as an alternative to conventional venous blood sampling for quantitation of tacrolimus concentrations. METHODS: A bioanalytical method for the quantitation of tacrolimus in human whole blood samples collected on MITRA tips was developed, using liquid-liquid extraction followed by liquid chromatography with tandem mass spectrometry detection. Validation experiments were performed according to the current Food and Drug Administration and European Medicines Agency guidelines on validation of bioanalytical methods. Validation criteria included assay specificity and sensitivity, interference, carryover, accuracy, precision, dilution integrity, matrix effect, extraction recovery, effect of hematocrit and hyperlipidemia, and stability. RESULTS: All assay validation results were within the required acceptance criteria, indicating a precise and accurate tacrolimus quantitation method. The validated assay range was 1.00-50.0 ng/mL. No interference, carryover or matrix effect was observed. Extraction recovery was acceptable across the assay range. Samples were stable for up to 96 days at -20°C and 20°C, and 28 days at 40°C. Hematocrit, hyperlipidemia, and lot-to-lot differences in the nominal absorption volume of the 10-µL MITRA tips were shown not to influence tacrolimus quantitation by this assay method. CONCLUSIONS: The bioanalytical method validated in this study is appropriate and practical for the quantitation of tacrolimus in human whole blood samples collected using the MITRA microsampling device.

Intermittent micafungin for prophylaxis in a rat model of chronic Candida albicans gut colonization.

BACKGROUND: During antifungal prophylaxis, micafungin is generally infused IV once daily over 1 h. In practice, less-frequent dosing could improve the quality of life in patients requiring long-term treatment or prophylaxis. The feasibility of this approach was assessed using humanized doses of daily or infrequent micafungin regimens. OBJECTIVES: To evaluate the effectiveness of intermittent high-dose micafungin, simulating human exposure, for prophylaxis of invasive candidiasis in a rat model of chronic Candida albicans gastrointestinal colonization and systemic dissemination. METHODS: Two weeks post-infection with an oral challenge of C. albicans, Sprague-Dawley rats were immunocompromised with a cytotoxic drug and a steroid. Rats received IV infusions of: daily vehicle control; daily subcutaneous micafungin (20 mg/kg SC); high-dose micafungin (20 mg/kg bolus SC + 80 mg/kg infusion/72 h, to simulate intermittent human dosing of 300 mg/72 h); or daily fluconazole by mouth (10 mg/kg PO). The effects of antifungal prophylaxis on faecal fungal burden and systemic C. albicans dissemination were evaluated. RESULTS: A rat model of chronic C. albicans gastrointestinal colonization and systemic dissemination was established, characterized by a sustained microbiological burden over 29 days and fungal recovery from normally sterile tissues. Using this model, intermittent high-dose micafungin (delivered via iPrecio pumps) to simulate humanized doses of 300 mg/72 h was significantly more effective than vehicle control, as effective as once-daily micafungin and similar to daily fluconazole at reducing faecal burden and preventing systemic dissemination. CONCLUSIONS: These data indicate that intermittent high-dose micafungin can be as effective as daily therapy, supporting clinical assessment in high-risk patients requiring long-term antifungal prophylaxis.

Long-Term Kidney Transplant Outcomes: Role of Prolonged-Release Tacrolimus.

Tacrolimus has significantly improved outcomes for kidney transplant patients and remains the cornerstone of immunosuppressive therapy. While improvements in short-term outcomes in transplantation have been achieved in recent years, maintaining long-term graft survival remains a challenge in kidney transplantation. Minimizing risk factors for poor long-term kidney graft function and survival, and modifying tacrolimus regimens in the early and maintenance phases post-transplantation are essential to maintain long-term kidney transplant outcomes. Tacrolimus has a narrow therapeutic window, resulting in a tightly defined range of optimal drug exposure. Underimmunosuppression is associated with long-term risks, such as the development of donor-specific antibodies and antibody-mediated rejection, with a high possibility of a decline in kidney function and progression to graft failure. Conversely, prolonged overimmunosuppression carries a risk of drug-related adverse events. This review provides an overview of the differences in the formulation, delivery, and pharmacokinetic profiles between immediate- and prolonged-release tacrolimus and evaluates the effect of prolonged-release tacrolimus on the risk factors for poor outcomes in kidney transplantation. Recent evidence is used to provide guidance on target tacrolimus trough levels in the early and maintenance phases post-transplantation, with a view to improving long-term kidney graft function.

Long-term, prolonged-release tacrolimus-based immunosuppression in de novo kidney transplant recipients: 5-year prospective follow-up of the ADHERE study patients.

The objectives of this study were to assess long-term graft survival, patient survival, renal function, and acute rejections in de novo kidney transplant recipients, treated with once-daily prolonged-release tacrolimus-based therapy. The study was a 5-year non-interventional prospective follow-up of patients from the ADHERE study, a Phase IV 12-month open-label assessment of patients randomized to receive prolonged-release tacrolimus in combination with mycophenolate mofetil (MMF) (Arm 1) or sirolimus (Arm 2). From 838 patients in the randomized study, 587 were included in the long-term follow-up, of whom 510 completed the study at year 5. At 1 year post-transplant, graft and patient survival rates were 93.0% and 97.8%, respectively, and at 5 years were 84.0% and 90.8%, respectively. Cox proportional hazards analysis showed no association between graft loss, initial randomized treatment arm, donor age, donor type, or sex. The 5-year acute rejection-free survival rate was 77.4%, and biopsy-confirmed acute rejection-free survival rate was 86.0%. Renal function remained stable over the follow-up period: mean ± SD eGFR 4-variable modification diet in renal disease formula (MDRD4) was 52.3 ± 21.6 ml/min/1.73 m2 at 6 months and 52.5 ± 23.0 ml/min/1.73 m2 at 5 years post-transplant. These findings support the role of long-term once-daily prolonged-release tacrolimus-based immunosuppression, in combination with sirolimus or MMF, for renal transplant recipients in routine clinical practice.

Efficacy and safety of tacrolimus in de novo pediatric transplant recipients randomized to receive immediate- or prolonged-release tacrolimus.

BACKGROUND AND AIMS: This multicenter trial compared immediate-release tacrolimus (IR-T) vs prolonged-release tacrolimus (PR-T) in de novo kidney, liver, and heart transplant recipients aged <16 years. Each formulation had similar pharmacokinetic (PK) profiles. Follow-up efficacy and safety results are reported herein. MATERIALS AND METHODS: Patients, randomized 1:1, received once-daily, PR-T or twice-daily, IR-T within 4 days of surgery. After a 4-week PK assessment, patients continued randomized treatment for 48 additional weeks. At Year 1, efficacy assessments included the number of clinical acute rejections, biopsy-confirmed acute rejection (BCAR) episodes (including severity), patient and graft survival, and efficacy failure (composite of death, graft loss, BCAR, or unknown outcome). Adverse events were assessed throughout. RESULTS: The study included 44 children. At Year 1, mean ± standard deviation tacrolimus trough levels were 6.6 ± 2.2 and 5.4 ± 1.6 ng/mL, and there were 2 and 7 acute rejection episodes in the PR-T and IR-T groups, respectively. No cases of graft loss or death were reported during the study. The overall efficacy failure rate was 18.2% (PR-T n = 1; IR-T n = 7). CONCLUSIONS: In pediatric de novo solid organ recipients, the low incidence of BCAR and low efficacy failure rate suggest that PR-T-based immunosuppression is effective and well tolerated to 1-year post-transplantation.

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.

The Effect of Donor Age and Recipient Characteristics on Renal Outcomes in Patients Receiving Prolonged-Release Tacrolimus After Liver Transplantation: Post-Hoc Analyses of the DIAMOND Study.

BACKGROUND The DIAMOND study of de novo liver transplant patients showed that prolonged-release tacrolimus exposure in the acute post-transplant period maintained renal function over 24 weeks of treatment. To assess these findings further, we performed a post-hoc analysis in patients according to baseline kidney function, Model for End-stage Liver Disease [MELD] scores, and donor age. MATERIAL AND METHODS Patients received prolonged-release tacrolimus (initial-dose, Arm 1: 0.2 mg/kg/day, Arm 2: 0.15-0.175 mg/kg/day, Arm 3: 0.2 mg/kg/day delayed until Day 5), mycophenolate mofetil and 1 steroid bolus. Arms 2 and 3 also received basiliximab. The recommended tacrolimus target trough levels to Day 42 post-transplantation were 5-15 ng/mL in all arms. In this post-hoc analysis, change in renal outcome, based on estimated glomerular filtration rate (eGFR), Modified Diet in Renal Disease-4 (MDRD4), values from baseline to Week 24 -post-transplantation, were assessed according to baseline patient factors: eGFR (≥60 and ˂60 mL/min/1.73 m²), MELD score (˂25 and ≥25) and donor age (˂50 and ≥50 years). RESULTS Baseline characteristics were comparable (Arms 1-3: n=283, n=287, n=274, respectively). Patients with baseline renal function, eGFR ≥60 mL/min/1.73 m², experienced a decrease in eGFR in all tacrolimus treatment arms. In patients with lower baseline renal function (eGFR ˂60 mL/min/1.73 m²), an advantage for renal function was observed with both the early lower-dose and delayed higher-dose tacrolimus regimens compared with the early introduction of higher-dose tacrolimus. At Week 24, renal function was higher in the early-lower tacrolimus arm with older donors, and the delayed higher-dose tacrolimus arm with younger donors, both compared with early higher-dose tacrolimus. CONCLUSIONS Pre-transplantation factors, such as renal function and donor age, could guide the choice of prolonged-release tacrolimus regimen following liver transplantation.

A Novel, Dose-Adjusted Tacrolimus Trough-Concentration Model for Predicting and Estimating Variance After Kidney Transplantation.

BACKGROUND AND OBJECTIVE: Given that a high intrapatient variability (IPV) of tacrolimus whole blood concentration increases the risk for a poor kidney transplant outcome, some experts advocate routine IPV monitoring for detection of high-risk patients. However, attempts to estimate the variance of tacrolimus trough concentrations (TTC) are limited by the need for patients to receive a fixed dose over time and/or the use of linear statistical models. A goal of this study is to overcome the current limitations through the novel application of statistical methodology generalizing the relationship between TTC and dose through the use of nonparametric functional regression modeling. METHODS: With TTC as a response and dose as a covariate, the model employs an unknown bivariate function, allowing for the potentially complex, nonlinear relationship between the two parameters. A dose-adjusted variance of TTC is then derived based on standard functional principal component analysis (FPCA). To assess the model, it was compared against an FPCA-based model and linear mixed-effects models using prediction error, bias, and coverage probabilities for simulated data as well as phase III data from the Astellas new drug application studies for extended-release tacrolimus. RESULTS: Our numerical investigation indicates that the new model better predicts dose-adjusted TTCs compared with the prediction of linear mixed effects models. Estimated coverage probabilities also indicate that the new model accurately accounts for the variance of TTC during the periods of large fluctuation in dose, whereas the linear mixed effects model consistently underestimates the coverage probabilities because of the inaccurate characterization of TTC fluctuation. CONCLUSION: This is the first known application of a functional regression model to assess complex relationships between TTC and dose in a real clinical setting. This new method has applicability in future clinical trials including real-world data sets due to flexibility of the nonparametric modeling approach.

Pharmacokinetic Profile of Prolonged-Release Tacrolimus When Administered via Nasogastric Tube in De Novo Liver Transplantation: A Sub-Study of the DIAMOND Trial.

BACKGROUND For patients unable to swallow during the immediate post-transplant period, immunosuppressant therapy may be initiated by administering prolonged-release tacrolimus as a suspension via a nasogastric tube. MATERIAL AND METHODS In this sub-study of the DIAMOND randomized controlled trial of prolonged-release tacrolimus in de novo liver transplant recipients, we investigated the pharmacokinetic (PK) profile of prolonged-release tacrolimus when administered via nasogastric tube immediately post-transplant. PK analyses were performed on whole-blood samples collected on Day 1 of tacrolimus administration and on Day 3 post-transplantation. Endpoints included AUC0-24, Cmax, Tmax, and Cmin. RESULTS In total, 10 patients were included in the PK sub-study. The overall mean daily dose of prolonged-release tacrolimus administered via nasogastric tube was higher on Day 1 (0.179 mg/kg) vs. Day 3 (0.140 mg/kg). Mean AUC0-24 was higher and less variable on Day 3 vs. Day 1 (AUC0-24 (coefficient of variation; CV): 301 (50.8) vs. 193 (94.5) ng·h/mL). Mean Cmax was lower and median Tmax was shorter on Day 1 vs. Day 3 (Cmax (CV): 15.1 (73.9) vs. 19.1 (47.9) ng/mL; Tmax (range): 2.0 (2.0-24.0) vs. 4.5 (0.5-24.0) h). A similar pattern was also observed when data were normalized for dose and body weight. CONCLUSIONS In contrast to previously reported findings in healthy volunteers, nasogastric administration of prolonged--release tacrolimus suspension in liver transplant patients did not substantially affect the PK profile of tacrolimus vs. intact capsules. Nasogastric administration is thus a feasible option to ensure appropriate early tacrolimus exposure in de novo liver transplant recipients.

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 Cmax 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.

Pharmacokinetics of tacrolimus granules in pediatric de novo liver, kidney, and heart transplantation: The OPTION study.

Tacrolimus granules were developed for patients who are unable to swallow capsules. Therapeutic drug monitoring (TDM) is required to optimize efficacy and safety, which is based on Ctrough for tacrolimus capsules. Pharmacokinetic (PK) data for tacrolimus granules are required to establish the basis for TDM in those who are unable to swallow capsules. In this phase IV study (NCT01371331) of children undergoing liver, kidney, or heart transplantation, patients received tacrolimus granules 0.15 mg/kg twice daily; first dose was administered within 24 hours of reperfusion. PK analysis samples were collected after reperfusion, after first dose of tacrolimus (Day 1), and at steady state (Day 7; >4 days stable dose). Of the 52 transplant recipients enrolled, 38 had two evaluable PK profiles. Mean AUCtau after first dose of tacrolimus was 211, 97, and 224 hour*ng/mL in liver, kidney, and heart transplant recipients, respectively; corresponding mean AUCtau at steady state was 195, 208, and 165 hour*ng/mL. Ctrough and AUCtau were positively correlated after first dose of tacrolimus and at steady state (Pearson's coefficients: r = 0.81 and r = 0.87, respectively). This study demonstrated that Ctrough is a reliable marker for TDM in pediatric transplant recipients treated with tacrolimus granules, consistent with TDM for other tacrolimus formulations.

Comparative pharmacokinetics of tacrolimus in de novo pediatric transplant recipients randomized to receive immediate- or prolonged-release tacrolimus.

Phase 2, parallel-group, multicenter, open-label, 4-week study, comparing PK of PR-T vs IR-T in de novo pediatric patients undergoing primary kidney, liver, or heart transplantation. Patients randomized 1:1 to receive once daily, PR-T-, or twice-daily, IR-T-based regimens; dose adjustments permitted after Day 1. Twenty-four-hour PK profiles collected on Days 1, 7, and 28. Primary endpoint: tacrolimus AUC24 . Secondary end points included tacrolimus C24 and Cmax . Endpoints compared between PR-T and IR-T on Days 1, 7, and 28. Predefined similarity interval for CIs of LSM ratios: 80%-125%. PK analysis set comprised 33 patients (PR-T, n = 15; IR-T, n = 18). Overall, AUC24 and Cmax were lower on Day 1 vs 7 and 28. Geometric LSM ratios of PR-T:IR-T on Days 1, 7, and 28 were 66.3%, 92.5%, 99.9%, respectively, for AUC24 ; 66.3%, 82.2%, 90.9% for C24 ; and 77.3%, 120.3%, 92.2% for Cmax . AUC24 90% CI within predefined similarity interval on Day 28; other 90% CIs fell outside. Linear relationship was similar between AUC24 and C24 , and between tacrolimus formulations, suggesting that the same therapeutic drug monitoring method can be used with both formulations in de novo pediatric allograft recipients.

Relative bioavailability of single doses of prolonged-release tacrolimus administered as a suspension, orally or via a nasogastric tube, compared with intact capsules: a phase 1 study in healthy participants.

OBJECTIVE: Tacrolimus, an immunosuppressant widely used in solid organ transplantation, is available as a prolonged-release capsule for once-daily oral administration. In the immediate postsurgical period, if patients cannot take intact capsules orally, tacrolimus therapy is often initiated as a suspension of the capsule contents, delivered orally or via a nasogastric tube. This study evaluated the relative bioavailability of prolonged-release tacrolimus suspension versus intact capsules in healthy participants. DESIGN: A phase 1, open-label, single-dose, cross-over study. SETTING: A single clinical research unit. PARTICIPANTS: In total, 20 male participants, 18-55 years old, entered and completed the study. INTERVENTIONS: All participants received nasogastric administration of tacrolimus 10 mg suspension in treatment period 1, with randomisation to oral administration of suspension or intact capsules in periods 2 and 3. Blood concentration-time profile over 144 hours was used to estimate pharmacokinetic parameters. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary end point: relative bioavailability of prolonged-release intact capsule versus oral or nasogastric administration of prolonged-release tacrolimus suspension (area under the concentration-time curve (AUC) from time 0 to infinity post-tacrolimus dose (AUC0-∞); AUC measured until the last quantifiable concentration (AUC0-tz); maximum observed concentration (Cmax); time to Cmax (Tmax)). Tolerability was assessed throughout the study. RESULTS: Relative bioavailability of prolonged-release tacrolimus suspension administered orally was similar to intact capsules, with a ratio of least-square means for AUC0-tz and AUC0-∞ of 1.05 (90% CI 0.96 to 1.14). Bioavailability was lower with suspension administered via a nasogastric tube versus intact capsules (17%; ratio 0.83; CI 0.76 to 0.92). Cmax was higher for oral and nasogastric suspension (30% and 28%, respectively), and median Tmax was shorter (difference 1.0 and 1.5 hours postdose, respectively) versus intact capsules (2.0 hours). Single 10 mg doses of tacrolimus were well tolerated. CONCLUSIONS: Compared with intact capsules, the rate of absorption of prolonged-release tacrolimus from suspension was faster, leading to higher peak blood concentrations and shorter time to peak; relative bioavailability was similar with suspension administered orally.

Pharmacokinetics of prolonged-release tacrolimus versus immediate-release tacrolimus in de novo liver transplantation: A randomized phase III substudy.

BACKGROUND: With the same dose of tacrolimus, lower systemic exposure on the first day of dosing has been reported for prolonged-release tacrolimus compared with immediate-release tacrolimus, prompting investigation of differing initial doses. METHODS: This substudy of a double-blind, randomized, phase III trial in de novo liver transplant recipients compared the pharmacokinetics of once-daily prolonged-release tacrolimus (initial dose: 0.2 mg/kg/day) versus twice-daily immediate-release tacrolimus (initial dose: 0.1 mg/kg/day) during the first 2 weeks post-transplant. RESULTS: Pharmacokinetic data were analyzed from patients receiving prolonged-release tacrolimus (n=13) and immediate-release tacrolimus (n=12). Mean systemic exposure (AUC0-24 ) was higher with prolonged-release versus immediate-release tacrolimus. Dose-normalized AUC0-24 (normalized to 0.1 mg/kg/day) showed generally lower exposure with prolonged-release tacrolimus versus immediate-release tacrolimus. There was good correlation between AUC0-24 and concentration at 24 hours after the morning dose (r=.96 and r=.86, respectively), and the slope of the line of best fit was similar for both formulations. CONCLUSIONS: Doubling the initial starting dose of prolonged-release tacrolimus compared with immediate-release tacrolimus overcompensated for lower exposure on Day 1. A 50% higher starting dose of prolonged-release tacrolimus than immediate-release tacrolimus may be required for similar systemic exposure. However, doses of both formulations can be optimized using the same trough-level monitoring system. (ClinicalTrials.gov number: NCT00189826).

Incidence of Posttransplantation Diabetes Mellitus in De Novo Kidney Transplant Recipients Receiving Prolonged-Release Tacrolimus-Based Immunosuppression With 2 Different Corticosteroid Minimization Strategies: ADVANCE, A Randomized Controlled Trial.

BACKGROUND: ADVANCE (NCT01304836) was a phase 4, multicenter, prospectively randomized, open-label, 24-week study comparing the incidence of posttransplantation diabetes mellitus (PTDM) with 2 prolonged-release tacrolimus corticosteroid minimization regimens. METHODS: All patients received prolonged-release tacrolimus, basiliximab, mycophenolate mofetil and 1 bolus of intraoperative corticosteroids (0-1000 mg) as per center policy. Patients in arm 1 received tapered corticosteroids, stopped after day 10, whereas patients in arm 2 received no steroids after the intraoperative bolus. The primary efficacy variable was the diagnosis of PTDM as per American Diabetes Association criteria (2010) at any point up to 24 weeks postkidney transplantation. Secondary efficacy variables included incidence of composite efficacy failure (graft loss, biopsy-proven acute rejection or severe graft dysfunction: estimated glomerular filtration rate (Modification of Diet in Renal Disease-4) <30 mL/min per 1.73 m), acute rejection and graft and patient survival. RESULTS: The full-analysis set included 1081 patients (arm 1: n = 528, arm 2: n = 553). Baseline characteristics and mean tacrolimus trough levels were comparable between arms. Week 24 Kaplan-Meier estimates of PTDM were similar for arm 1 versus arm 2 (17.4% vs 16.6%; P = 0.579). Incidence of composite efficacy failure, graft and patient survival, and mean estimated glomerular filtration rate were also comparable between arms. Biopsy-proven acute rejection and acute rejection were significantly higher in arm 2 versus arm 1 (13.6% vs 8.7%, P = 0.006 and 25.9% vs 18.2%, P = 0.001, respectively). Tolerability profiles were comparable between arms. CONCLUSIONS: A prolonged-release tacrolimus, basiliximab, and mycophenolate mofetil immunosuppressive regimen is efficacious, with a low incidence of PTDM and a manageable tolerability profile over 24 weeks of treatment. A lower incidence of biopsy-proven acute rejection was seen in patients receiving corticosteroids tapered over 10 days plus an intraoperative corticosteroid bolus versus those receiving an intraoperative bolus only.