Consensus Report on Therapeutic Drug Monitoring of Mycophenolic Acid in Solid Organ Transplantation
ABSTRACT With the increasing use of mycophenolic acid (MPA) in solid organ transplantation, the need for more accurate drug dosing has become evident. Personalized immunosuppressive therapy requires better strategies for avoidance of drug-related toxicity while maintaining efficacy. Few studies have assessed the clinical usefulness of therapeutic drug monitoring (TDM) of MPA in solid organ transplantation in a prospective way, and they have produced opposing results. To provide clinicians with an objective and balanced clinical interpretation of the current scientific evidence on TDM of MPA, a consensus meeting involving 47 experts from around the world was commissioned by The Transplantation Society and held in Rome on November 20 to 21, 2008. The goal of this consensus meeting was to offer information to transplant practitioners on clinically relevant pharmacokinetic characteristics of MPA, to rationalize the basis for currently advised target exposure ranges for MPA in various types of organ transplantation, and to summarize available methods for application of MPA TDM in clinical practice. Although this consensus report does not evaluate the final role of MPA TDM in transplantation, it seeks to examine the current scientific evidence for concentration-controlled dosing of MPA.
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ABSTRACT: While mycophenolate mofetil (MMF) has replaced corticosteroids as immunosuppression in cord blood transplantation (CBT), optimal MMF dosing has yet to be established. We intensified MMF dosing from every 12 to 8 hours to augment graft-versus-host disease (GVHD) prophylaxis in double-unit CBT (dCBT) and evaluated outcomes according to the total daily MMF dose/kg in 174 double-unit CBT recipients (median age 39 years, range 1-71) transplanted for hematologic malignancies. Recipients of a MMF dose ≤ the median (36 mg/kg/day) had an increased day 100 grade III-IV acute GVHD (aGVHD) incidence compared with patients who received > 36 mg/kg/day (24% versus 8%, p = 0.008). Recipients of ≤ the median dose who had highly HLA-allele (1-3/6) mismatched dominant units had the highest day 100 grade III-IV aGVHD incidence of 37% (p = 0.009). This finding was confirmed in multivariate analysis (p = 0.053). In 83 patients evaluated for mycophenolic acid (MPA) troughs, those with a mean week 1-2 trough < 0.5 mcg/mL had an increased day 100 grade III-IV aGVHD of 26% versus 9% (p = 0.063), and those who received a low total daily MMF dose and had a low week 1-2 MPA trough had a 40% incidence (p = 0.008). Higher MMF dosing or MPA troughs had no impact on engraftment after myeloablation. This analysis supports intensified MMF dosing in mg/kg/day and MPA trough level monitoring early post-transplant in dCBT recipients. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 02/2015; 21(5). DOI:10.1016/j.bbmt.2015.01.024 · 3.35 Impact Factor
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ABSTRACT: AimTo date, neither the benefit of mycophenolic acid (MPA) therapeutic drug monitoring (TDM), the prodrug of mycophenolate mofetil (MMF), nor the optimal monitoring technique have been established in autoimmune diseases. This study was undertaken to confirm, in a cohort of new patients, the plasma MPA thresholds previously published in patients with systemic lupus erythematosus (SLE) or vasculitides.MethodsMPA areas under the concentration–time curves between 0 and 12 hours, 12-hour trough concentrations and pre-dose concentrations (C0) were determined for 23 patients with SLE and 21 with systemic vasculitides. Relationship between patients’ pharmacokinetic (PK) variables and their clinical outcomes during follow-up were analyzed.ResultsIn both autoimmune diseases, at PK assessment, median MPA C0 for patients with uncontrolled disease was significantly lower than that of patients with stable disease or in remission, 1.6 mg l–1 (IQR: 0.9-2.1 mg l–1) vs. 2.95 mg l–1 (IQR: 1.38-3.73 mg l–1) for SLE (P = 0.048) and 1.55 mg l–1 (IQR: 0.98-2.18mg l–1) vs. 3 mg l–1 (IQR: 2.2-4.4 mg l–1) for vasculitides (P = 0.016). According to our receiver operating characteristics curve analysis, a C0 threshold of 2.5–3 mg l–1 was best able to discriminate a flare (SLE: 88% sensitivity, 80% specificity; vasculitides: 100% sensitivity, 90% specificity). Patients with C0 ≥2.5–3 mg l–1 at inclusion had better clinical outcomes during the 12-months following PK assessment.Conclusion Provided that the benefit of TDM in patients with autoimmune diseases would be confirmed by randomized–controlled trials, it might be based on the C0 measured ∼12 hours postdose.British Journal of Clinical Pharmacology 07/2014; DOI:10.1111/bcp.12462 · 3.69 Impact Factor
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ABSTRACT: Two oral mycophenolic acid (MPA) formulations, immediate-release mycophenolate mofetil and enteric-coated mycophenolate sodium, have been shown to differ regarding some drug-drug interactions. The aim was to assess whether the effects of cyclosporine (CsA) on steady-state pharmacokinetics (PK) of MPA in renal transplant patients were affected by MPA formulation. A prospective, stratified observational study based on therapeutic drug monitoring of MPA (6 total plasma concentrations over a 12-hour dosing interval, τ) in consecutive stable adult renal transplant recipients (n = 68). Patients treated with enteric-coated mycophenolate sodium (n = 45) or mycophenolate mofetil (n = 23) and with either CsA (microemulsion, n = 43) or tacrolimus (Tac) (immediate release, n = 25) were comparable regarding demographics, comorbidity, renal and liver functions, comedication, corticosteroid dose, CsA or Tac dose, and trough concentrations. Based on dose-normalized MPA concentrations and with adjustment for age, sex, body mass index, estimated glomerular filtration rate, and corticosteroid dose, CsA (as compared with Tac) consistently reduced MPA area under the concentration-time curve during the dosing interval at steady state overall [geometric mean ratio (GMR), 0.78; 95% confidence interval, 0.62-0.99] and by MPA formulation (by 22% and 21%, respectively), increased CLT/F,ss overall (1.31; 1.00-1.70) and by formulation (by 25% and 36%, respectively), reduced morning predose MPA concentration overall (0.59; 0.38-0.92) and by formulation (by 34% and 47%, respectively), increased peak-trough fluctuation overall (1.51; 1.06-2.17) and by formulation (by 58% and 45%, respectively), and prolonged tmax,ss overall (adjusted median difference 0.58, 0.04-1.12 hours) and by formulation (by 0.6 and 0.5 hours, respectively). Qualitatively and quantitatively, the effect of CsA on steady-state PK of MPA is not conditional on MPA formulation.Therapeutic drug monitoring 02/2014; DOI:10.1097/FTD.0000000000000052 · 1.93 Impact Factor