Pharmacokinetic Evaluation of an Intensified and Decreasing Dosing Regimen of Mycophenolate Sodium in Combination With Tacrolimus Post Kidney Transplant: The Myfortic Study

Mycophenolate acid (MPA) has been developed and approved in combination with cyclosporine and has been used in kidney transplantation for more than a decade. At present, combination of tacrolimus and mycophenolate acid tends to be considered as the standard of care for maintenance immunosuppression in kidney transplantation. Mainly due to a different effect on the entero-hepatic recycling pathway, cyclosporine and tacrolimus differently interfere with MPA clearance. When used with tacrolimus, MPA dosage has thus to be adjusted and cannot be extrapolated from what is recommended for a cyclosporine-based treatment. However, there is currently no clear guideline for MPA dosing when this drug is used in combination with tacrolimus. This is potentially detrimental for patients since under-or overexposure of MPA has been clinically linked to the outcome of transplantation.

The purpose of this study is to pharmacologically validate an original MPA dosing regimen in combination with tacrolimus within the three months post-kidney transplant. This regimen consists in an intensified dosing of mycophenolate sodium during the earliest period of transplantation in order to rapidly reach the appropriate MPA blood exposure followed by a gradual decrease in dose in order to prevent MPA overexposure.