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A Study to Assess the Pharmacokinetics of a Modified-release Tacrolimus Based Immunosuppression Regimen in Stable Kidney Transplant Patients

Phase 2
Completed
Conditions
Kidney Transplantation
Interventions
Registration Number
NCT00282568
Lead Sponsor
Astellas Pharma Inc
Brief Summary

A study to assess the pharmacokinetics, safety and effectiveness of tacrolimus in stable kidney transplant patients converted from a Prograf® based immunosuppression regimen to a modified release tacrolimus based immunosuppression regimen.

Detailed Description

This is a Phase II open-label, multi-center conversion study in stable, adult kidney transplant recipients to assess the pharmacokinetics, safety and effectiveness of tacrolimus in stable kidney transplant patients converted from a Prograf® based immunosuppression regimen to a modified release tacrolimus based immunosuppression regimen.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
70
Inclusion Criteria
  • Patient is currently receiving Prograf ® based immunosuppressive therapy for kidney transplantation.
  • Patient has stable whole blood trough level concentrations of Prograf® and is clinically stable
Exclusion Criteria
  • Patient has previously received an organ transplant other than a kidney
  • Patient is currently receiving sirolimus immunosuppression therapy.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Tacrolimus Modified ReleaseTacrolimus Modified Release (MR)Participants were enrolled into the study on their stable twice-daily (bid) dose of tacrolimus on Day 1 and continued to receive a stable bid dose of tacrolimus through Day 7. Participants then converted to Tacrolimus Modified Release (MR), administered once daily at an equivalent dose to the patient's previous stable total daily dose of tacrolimus. Participants who completed the 4-week pharmacokinetic treatment period with tacrolimus MR could continue receiving tacrolimus MR as part of the extended treatment period of the study. Dose adjustments were allowed in order to maintain tacrolimus trough concentrations within the target range of 5 to 15 ng/mL and for clinical reasons.
Tacrolimus Modified ReleasetacrolimusParticipants were enrolled into the study on their stable twice-daily (bid) dose of tacrolimus on Day 1 and continued to receive a stable bid dose of tacrolimus through Day 7. Participants then converted to Tacrolimus Modified Release (MR), administered once daily at an equivalent dose to the patient's previous stable total daily dose of tacrolimus. Participants who completed the 4-week pharmacokinetic treatment period with tacrolimus MR could continue receiving tacrolimus MR as part of the extended treatment period of the study. Dose adjustments were allowed in order to maintain tacrolimus trough concentrations within the target range of 5 to 15 ng/mL and for clinical reasons.
Primary Outcome Measures
NameTimeMethod
Area Under the Concentration-time Curve From Time 0 to 24 Hours (AUC0-24) for TacrolimusFor tacrolimus, Days 1 and 7 at 0 (pre-dose), 0.5, 1, 2, 3, 6, 8, 12 (pre-dose), 13, 14, 15, 18, 20, and 24 hours. For tacrolimus MR, Days 14 and 21 pre-dose and 0.5, 1, 2, 3, 4, 6, 8, 12, 15, 18, 20, and 24 hours post-dose.

The area under the concentration-time curve was calculated from whole blood tacrolimus concentrations for both tacrolimus and tacrolimus MR at steady state using the trapezoidal rule.

Maximum Observed Concentration (Cmax) of TacrolimusFor tacrolimus, Days 1 and 7 at 0 (pre-dose), 0.5, 1, 2, 3, 6, 8, 12 (pre-dose), 13, 14, 15, 18, 20, and 24 hours. For tacrolimus MR, Days 14 and 21 pre-dose and 0.5, 1, 2, 3, 4, 6, 8, 12, 15, 18, 20, and 24 hours post-dose.

The maximum concentration was calculated from whole blood tacrolimus concentrations for both tacrolimus and tacrolimus MR at steady state, without interpolation.

Minimum Concentration of Tacrolimus (Cmin)Days 1 and 7 (tacrolimus) and Days 14 and 21 (tacrolimus MR), 24 hours post-dose.

The trough (minimum) concentration of tacrolimus determined from the tacrolimus whole blood concentration value at the 24-hour time point post- dose, prior to receiving the next dose.

Time to Maximum Observed Concentration of Tacrolimus (Tmax)For tacrolimus, Days 1 and 7 at 0 (pre-dose), 0.5, 1, 2, 3, 6, 8, 12 (pre-dose), 13, 14, 15, 18, 20, and 24 hours. For tacrolimus MR, Days 14 and 21 pre-dose and 0.5, 1, 2, 3, 4, 6, 8, 12, 15, 18, 20, and 24 hours post-dose.

The time to reach the maximum concentration of tacrolimus was calculated from whole blood tacrolimus concentrations for both tacrolimus and tacrolimus MR at steady state, without interpolation.

Patient SurvivalFrom enrollment until the end of study (up to 60 months).

Patient Survival defined as any participant who did not die by the time of analysis.

Graft SurvivalFrom enrollment until the end of study (up to 60 months).

Graft survival was defined as any participant who did not meet the definition of graft loss, where graft loss was defined as graft failure (re-transplant or permanent return to dialysis (for more than 30 days)) or participants death.

Secondary Outcome Measures
NameTimeMethod
Percentage of Participants With Biopsy-confirmed Acute RejectionFrom enrollment until the end of study (up to 60 months).

Biopsy-confirmed acute rejection (BCAR) is defined as an episode of acute allograft rejection that was confirmed by biopsy results and was Banff grade ≥ IA. Biopsies were graded by the pathologist at the clinical site according to the 1997 Banff criteria: Borderline: No intimal arteritis present but foci of mild tubulitis; Grade I: Significant interstitial infiltration and foci of moderate to severe tubulitis; Grade II: Mild to severe intimal arteritis; Grade III: Transmural arteritis and/or arterial fibrinoid change and necrosis of medial smooth muscle cells with accompanying lymphocytic infiltrate in vessel.

Change From Baseline in Creatinine ClearanceBaseline (the last day of tacrolimus on Day 7), Day 35 (end of the pharmacokinetic phase) and end of treatment (EOT; the last observed value during treatment, maximum time on study was 60 months).

Renal function was assessed using creatinine clearance levels calculated using the Cockcroft-Gault formula, over the course of the study.

Time to Event for Patient Non SurvivalFrom enrollment until the end of study (up to 60 months).

For participants who died on study, the median number of days from enrollment to death due to any cause.

Time to Event for Graft Non SurvivalFrom enrollment until the end of study (up to 60 months).

For participants with graft loss, the median number of days from enrollment to graft loss. Graft loss was defined as graft failure (re-transplant or permanent return to dialysis (for more than 30 days)) or participant death.

Time to First Biopsy-confirmed Acute RejectionFrom enrollment until the end of study (up to 60 months).

For participants with a biopsy-confirmed acute rejection, the median number of days from enrollment to the date of biopsy confirmation. Biopsy-confirmed acute rejection (BCAR) is defined as an episode of acute allograft rejection that was confirmed by biopsy results and was Banff grade ≥ IA. Biopsies were graded by the pathologist at the clinical site according to the 1997 Banff criteria: Borderline: No intimal arteritis present but foci of mild tubulitis; Grade I: Significant interstitial infiltration and foci of moderate to severe tubulitis; Grade II: Mild to severe intimal arteritis; Grade III: Transmural arteritis and/or arterial fibrinoid change and necrosis of medial smooth muscle cells with accompanying lymphocytic infiltrate in vessel.

Grade of Biopsy-confirmed Acute Rejection EpisodesFrom enrollment until the end of study (up to 60 months).

Biopsy-confirmed acute rejection (BCAR) is defined as an episode of acute allograft rejection that was confirmed by biopsy results and was Banff grade ≥ IA. Biopsies were graded by the pathologist at the clinical site according to the 1997 Banff criteria: Borderline: No intimal arteritis present but foci of mild tubulitis; Grade I: Significant interstitial infiltration and foci of moderate to severe tubulitis; Grade II: Mild to severe intimal arteritis; Grade III: Transmural arteritis and/or arterial fibrinoid change and necrosis of medial smooth muscle cells with accompanying lymphocytic infiltrate in vessel.

For participants with more than one biopsy-confirmed acute rejection episode, the worst case grade is reported.

Number of Participants Receiving Anti-lymphocyte Antibody Therapy for Acute RejectionFrom enrollment until the end of study (up to 60 months).

Steroid-resistant rejection episodes were treated with anti-lymphocyte antibodies. If a participant had a histologically proven Banff Grade II or III rejection, they could be initiated on anti-lymphocyte antibody treatment per institutional practice. Biopsies were graded by the pathologist at the clinical site according to the 1997 Banff criteria: Borderline: No intimal arteritis present but foci of mild tubulitis; Grade I: Significant interstitial infiltration and foci of moderate to severe tubulitis; Grade II: Mild to severe intimal arteritis; Grade III: Transmural arteritis and/or arterial fibrinoid change and necrosis of medial smooth muscle cells with accompanying lymphocytic infiltrate in vessel.

Number of Participants With Multiple Rejection EpisodesFrom enrollment until the end of study (up to 60 months).

This analysis includes rejection episodes that were either confirmed by biopsy by the clinical site pathologist or were clinically treated.

Number of Participants With Clinically Treated Acute Rejection EpisodesFrom enrollment until the end of study (up to 60 months).

A clinically treated acute rejection episode was any biopsy-confirmed or suspected rejection episode that was treated with immunosuppressive therapy.

Number of Participants With Chronic RejectionFrom enrollment until the end of study (up to 60 months).

Due to the low number of participants with biopsy-confirmed acute rejection episodes, chronic rejection was not analyzed.

Number of Participants With Treatment FailureFrom enrollment until the end of study (up to 60 months).

Treatment failure was defined as discontinuation of study drug for any reason. Due to discontinuation of the study by the sponsor, treatment failure was not analyzed.

Change From Baseline in Serum CreatinineBaseline (the last day of tacrolimus on Day 7), Day 35 (end of the pharmacokinetic phase) and end of treatment (EOT; the last observed value during treatment, maximum time on study was 60 months).

Renal function was assessed using serum creatinine levels over the course of the study.

Primary Reason for Graft LossFrom enrollment until the end of study (up to 60 months).

The primary reason for graft loss was recorded by the Investigator. Graft loss was defined as graft failure (re-transplant or permanent return to dialysis) or death. GBM = glomerular basement membrane.

Number of Participants Returning to Permanent DialysisFrom enrollment until the end of study (up to 60 months).

Permanent dialysis defined as dialysis for longer than 30 days.

Safety as Assessed by Adverse Events, Laboratory Parameters and Vital SignsFrom the first dose of tacrolimus MR formulation through the day of last dose plus 10 days (approximately 60 months).

An adverse event was defined as any reaction, side effect or other untoward medical occurrence, regardless of the relationship to study drug which occurred during the conduct of a clinical study. Clinically significant adverse changes in clinical status, routine laboratory studies or physical examinations were considered adverse events.

A serious adverse event was any adverse event occurring at any dose that resulted in any of the following outcomes:

* Death

* Life-threatening adverse event

* Inpatient hospitalization or prolongation of existing hospitalization

* Persistent or significant disability or incapacity

* Congenital abnormality or birth defect

* Important medical event.

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