Investigating tacrolimus metabolism in kidney transplant patients

Tacrolimus Pharmacokinetic Subpopulations: Prospective Mechanistic Investigations of the Tacrolimus C/D Ratio

Observational University Hospital, Grenoble · NCT04526431

This study looks at how kidney transplant patients process a medication called tacrolimus over four years to see if it affects their kidney health and how genetics might play a role.

Quick facts

Study typeObservational
Enrollment180 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Hospital, Grenoble Academic / other
Locations2 sites (Grenoble, Auvergne-Rhône-Alpes and 1 other locations)
Trial IDNCT04526431 on ClinicalTrials.gov

What this trial studies

This observational study aims to analyze the concentrations of tacrolimus metabolites in kidney transplant patients over the first four years post-transplantation. It will compare the concentration-to-dose ratio (C/D ratio) of tacrolimus metabolites between patients classified as 'high rate metabolizers' and others to understand the impact on kidney graft survival. The study will also explore the genetic factors influencing tacrolimus metabolism and how different formulations of the drug may affect pharmacokinetics. By identifying metabolism patterns, the study seeks to improve immunosuppressive strategies for better patient outcomes.

Who should consider this trial

Good fit: Ideal candidates include kidney transplant patients within 7 days of their transplant who are being treated with tacrolimus as part of their immunosuppressive regimen.

Not a fit: Patients who have contraindications to tacrolimus or are already being treated with it prior to the study will not benefit from this research.

Why it matters

Potential benefit: If successful, this study could lead to improved management of tacrolimus therapy, enhancing kidney transplant survival rates.

How similar studies have performed: Previous studies have indicated a relationship between tacrolimus concentration and graft survival, suggesting that this approach may yield valuable insights.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Kidney transplant patients at the CHUGA, CHU Saint-Etienne or CHU Clermont-Ferrand, whose new transplant is no more than 7 days old (inclusive)
* Patients initially treated with tacrolimus as an immunosuppressant, combined with mycophenolate (MMF), mycophenolic acid (MPA) or everolimus (EVR), with or without corticotherapy.
* No plans to remove tacrolimus from the patient's immunosuppressive treatment (e.g. no plans to switch to belatacept a priori), during the first 4 years post-transplantation.
* Affiliation to or beneficiary of a social security scheme
* Able to read and understand the terms of the protocol
* Informed consent obtained, including specific consent for genetic analysis of target genes.
* For women of childbearing potential, presence of effective contraception (already acquired for patients treated with mycophenolic acid as an immunosuppressant).

Exclusion Criteria:

* Contraindication to the use of tacrolimus
* Patient already treated with tacrolimus at the time of transplantation
* Pregnant, parturient or breastfeeding women
* Patient deprived of liberty by judicial or administrative decision
* Patient under guardianship or curatorship, or receiving forced psychiatric care
* Person admitted to a health or social institution
* Subject cannot be contacted in case of emergency
* Subject in period of exclusion from another study

Where this trial is running

Grenoble, Auvergne-Rhône-Alpes and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Kidney Transplant Failure and RejectionImmunosuppression-related Infectious DiseaseKidney transplantationPharmacokineticTacrolimusConcentration-dose ratioPharmacogenetic
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.