A Prospective Study to Investigate Mycophenolic Acid (MPA) Exposure Through Area Under the Curve (AUC) in Renal Transplants Recipients Treated With Mycophenolate Mofetil (MMF) and After Conversion to Mycophenolate Sodium (EC-MPS)

A growing body of evidence has shown that mycophenolate acid (MPA) exposure assessment and dosage adjustment are necessary in patients treated with mycophenolate mofetil (MMF), but there is still limited information about the dose-exposure-effect relationship of the enteric-coated mycophenolate sodium (EC-MPS) formulation that has quite different physicochemical properties (TETT et al., 2011).

Pharmacokinetically guided exposure-controlled area under the concentration-time curve (AUC) approaches are helpful to limit interpatient variability of MPA exposure and to improve the clinical outcome of organ transplant recipients (TETT et al., 2011).

MPA area under the concentration-time curve values between 30 and 60 μg h/mL in the early post-transplant period reduces the risk of acute rejections and seems to be appropriate in renal allograft recipients taking mycophenolate sodium (MPS) and calcineurin inhibitors (GRINYÓ et al., 2009; SOMMERER et al., 2010).

Among the benefits of therapeutic drug monitoring of MPA are the evaluation of interaction between MPA and proton pump inhibitors and association of donor-specific antibodies reduction.

Inclusion criteria

• Age ≥ 18 years at the time of screening;
• Subjects above the sixth month post renal transplant;
• Subjects receiving mycophenolate mofetil;
• Women of childbearing potential (CBP) with a negative pregnancy test at screening (urine or serum);
• Women of CBP and men with sexual partners of CBP must agree to use a medically acceptable method of contraception throughout the study.

Exclusion criteria

• Subjects who, in the opinion of the investigator, are not able to complete the study;
• Recipients of multiple organ transplant (i.e., prior or concurrent transplantation of a non-renal allograft;
• Use of any investigational drug or treatment up to 4 weeks before enrollment;
• Subjects with a calculated GFR < 30ml/min (abbreviated MDRD formula);
• Subjects with a screening total white blood cell count (WBC) ≤ 2000/mm3, hemoglobin ≤ 10g/dL and platelet count ≤ 100000/mm3;
• TGO/AST, TGP/ALT and bilirubin with values three times higher that reference values;
• History of malignancy within 3 years enrollment other than adequately treated basal cell or squamous cell carcinoma of the skin;
• Subjects who are known to be human immunodeficiency virus (HIV), hepatitis B or hepatitis C;
• Chronic hepatic failure;
• Planned treatment with immunosuppressive therapies other than those described in the protocol;
• Recipients who required desensitization protocols.