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Tacrolimus or cyclosporine is prescribed with mycophenolic acid posttransplant and contributes to interpatient variability in mycophenolic acid pharmacokinetics and response. Cyclosporine inhibits enterohepatic circulation of the metabolite mycophenolic acid glucuronide, which is not described with tacrolimus. This study investigated mycophenolic acid pharmacokinetics and adverse effects in stable renal transplant recipients and the association with calcineurin inhibitors, sex, and race. Mycophenolic acid and mycophenolic acid glucuronide area under the concentration-time curve from 0 to 12 hours (AUC(0–12h)) and apparent clearance were determined at steady state in 80 patients receiving cyclosporine with mycophenolate mofetil and 67 patients receiving tacrolimus with mycophenolate sodium. Gastrointestinal adverse effects and hematologic parameters were evaluated. Statistical models evaluated mycophenolic acid pharmacokinetics and adverse effects. Mycophenolic acid AUC(0–12h) was 1.70-fold greater with tacrolimus (68.9 ± 30.9 mg·h/L) relative to cyclosporine (40.8 ± 17.6 mg·h/L); P < .001. Target mycophenolic acid AUC(0–12h) of 30–60 mg·h/L was achieved in 56.3% on cyclosporine compared with 34.3% receiving tacrolimus (P < .001). Mycophenolic acid clearance was 48% slower with tacrolimus (10.6 ± 4.7 L/h) relative to cyclosporine (20.5 ± 10.0 L/h); P < .001. Enterohepatic circulation occurred less frequently with cyclosporine (45%) compared with tacrolimus (78%); P < 0.001; with a 2.9-fold greater mycophenolic acid glucuronide AUC(0–12h) to mycophenolic acid AUC(0–12h) ratio (P < .001). Race did not affect mycophenolic acid pharmacokinetics. Gastrointestinal adverse effect scores were 2.2-fold higher with tacrolimus (P < .001) and more prominent in women (P = .017). Lymphopenia was more prevalent with tacrolimus (52.2%) than cyclosporine (22.5%); P < 0.001. Calcineurin inhibitors and sex contributed to interpatient variability in mycophenolic acid pharmacokinetics and adverse effects post-renal transplant, which could be attributed to differences in enterohepatic circulation.

Immunosuppressive therapy is used in solid organ transplant treatment, and mycophenolic acid (MPA) is one of the immunosuppressive drugs most used worldwide. It is a potent, selective, non-competitive, and reversible inosine monophosphate dehydrogenase (IMPDH) inhibitor that acts to inhibit guanine synthesis. To improve solubility, MPA is used as the prodrug mycophenolate mofetil (MMF) or as an enteric-coated mycophenolate sodium salt (EC-MPS). It is metabolized into mycophenolic acid phenyl glucuronide (MPAG), the inactive and major metabolite, and into acyl glucuronide (AcMPAG), pharmacologically active. In kidney transplantation, combined immunosuppressive therapy with cyclosporine (CsA) and tacrolimus (Tac) is widely used, showing beneficial effects. This paper aimed to review papers published in the last two decades and discuss factors that can interfere with the pharmacokinetics of MPA. Data collected confirm that MPA plasma levels should be monitored to evaluate immunosuppressive therapy since pharmacokinetics can be influenced by factors such as interpatient variability, coadministration of other immunosuppressive agents, post-transplant period, renal function, and dose. However, to perform drug monitoring, costs and facility may be limitations. Monitoring MPAG together with MPA would be a great improvement in therapy as it represents a big part of MPA levels and can be related to the increase of adverse effects.

Results from clinical studies indicate that azathioprine and enteric-coated mycophenolate sodium (EC-MPS) are safe and potent drugs in the treatment of atopic dermatitis (AD).(1-5) However, published data from large groups of non-selected patients is non-existent to date which hampers generalization to daily practice. In addition, head-to-head trials in which azathioprine and EC-MPS are compared, have never been performed. The primary objective was to perform an analysis of drug survival for azathioprine and EC-MPS in a long-term daily practice cohort of patients with AD. The secondary objective was to identify determinants of drug survival. This article is protected by copyright. All rights reserved.

Mycophenolic acid was first discovered in 1913 and first used clinically in the 1970s as an immunosuppressant to prevent organ transplantation rejection. It was later used in the treatment of psoriasis. However due to its side-effect profile and fears over its carcinogenic potential it was abandoned. From the late 1990s a prodrug, mycophenolate mofetil (MMF), was developed and more recently, enteric-coated mycophenolate sodium (EC-MPS), both of which have gained increasing use in the field of dermatology for a variety of skin conditions. This review discusses the pharmacology, mechanisms of action, side-effects and current clinical applications in dermatology of MMF and EC-MPS.

MORE was a four-yr, prospective, observational study at 40 transplant centers in the US. Data were analyzed to evaluate changes in mycophenolic acid (MPA) dosing over time in 904 de novo kidney transplant recipients receiving enteric-coated mycophenolate sodium (EC-MPS, n = 616) or mycophenolate mofetil (MMF, n = 288) with tacrolimus. Induction therapy and steroid treatment were similar in the two subpopulations. The proportion of patients receiving the maximal recommended MPA dose was 80.5%, 43.9%, 39.2%, 34.6%, and 30.1% at baseline and years 1, 2, 3, and 4, respectively. More patients received the maximal recommended MPA dose with EC-MPS vs. MMF at month 1 (79.2% vs. 71.7%, p = 0.016), month 3 (68.5% vs. 56.9%, p = 0.001), and month 6 (52.9% vs. 44.0%, p = 0.028). Multivariate analysis showed the risk of biopsy-proven acute rejection, graft loss or death to be similar for EC-MPS vs. MMF. Estimated glomerular filtration rate (GFR) was similar with EC-MPS vs. MMF at all time points. There were no significant differences in any category of adverse event between the EC-MPS and MMF cohorts during follow-up, including gastrointestinal events. In conclusion, MPA dose was maintained more effectively in the first six months after kidney transplantation using EC-MPS vs. MMF, without an increase in adverse events.

Aim Mycophenolate is an immunosuppressive agent which has been used in systemic lupus erythematosus (SLE) patients who have failed conventional therapy. However, the use of mycophenolate sodium in extra-renal SLE involvement has yet to be established. This study aimed to assess the efficacy of mycophenolate sodium in extra-renal SLE. Methods A total of 14 SLE patients without renal involvement were randomized either to receive mycophenolate sodium or other immunosuppressive agents. Patients were assessed monthly from baseline until week 16. Assessment parameters included SLE Disease Activity Index (SLEDAI) score, other organ-specific parameters and immunological parameters, including anti-double stranded DNA and C3. Steroid-sparing effect of mycophenolate sodium was also evaluated. Results Mycophenolate sodium produced a significant reduction in SLEDAI scores (P

Background Limited mycophenolic acid (MPA) data are available comparing racial influence on mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS) pharmacokinetics. Methods Intrapatient MPA pharmacokinetics of MMF versus EC-MPS were compared in 13 male African American (AA) and 14 Caucasian (C) renal transplant recipients (RTRs). RTRs were switched to equivalent doses of the alternate formulation for at least 10 days prior to the second study. Mycophenolic acid clearance and dose-normalized area under the concentration-time curve(0-12) (AUC*) were determined. Mixed model statistics evaluated the main effects of race, drug formulation, and interaction of race and drug formulation (R × D) with albumin, cyclosporine trough, renal function, and diabetes and enterhepatic recirculation. Results Significant R × D was identified for MPA AUC* for EC-MPS (AA, 0.056 ± 0.029 [mg·h/L]/mg; C, 0.080 ± 0.044 [mg·h/L]/mg) compared with MMF (AA, 0.053 ± 0.019 [mg·h/L]/mg; C, 0.060 ± 0.025 [mg·h/L]/mg), P = .022. Significant R × D was identified with albumin in the model for MPA clearance for MMF (AA, 21.7 ± 8.9 L/h; C, 20.5 ± 10.8 L/h) compared with EC-MPS (AA, 22.2 ± 10.1 L/h; C, 16.2 ± 9.1 L/h), P = .032. Conclusions Race influences MPA exposure between MMF and EC-MPS and may warrant therapeutic monitoring during formulation conversion.

Aim Cyclosporine (CsA), dosed to achieve C2 targets, has been shown to provide safe and efficacious immunosuppression when used with a mycophenolate and steroids for de novo kidney transplant recipients. This study examined whether use of enteric-coated mycophenolate sodium (EC-MPS) together with basiliximab and steroids would enable use of CsA dosed to reduced C2 targets in order to achieve improved graft function. Methods Twelve-month, prospective, randomized, open-label trial in de novo kidney transplant recipients in Australia. Seventy-five patients were randomized to receive either usual exposure (n = 33) or reduced exposure (n = 42) CsA, EC-MPS 720 mg twice daily, basiliximab and corticosteroids. Results There was no significant difference in mean Cockcroft-Gault CrCl (creatinine clearance) (60.2 ± 17.6 mL/min per 1.73 m2 vs 63.2 ± 24.3, P = 0.64 for usual versus reduced exposure respectively) at 6 months. There was no significant difference between treatment groups in the incidence of treatment failure defined as biopsy proven acute rejection, graft loss or death (secondary endpoint: 30.3% full exposure vs 35.7% reduced exposure). At 12 months the incidence of overall adverse events was the same in both groups. Conclusion This exploratory study suggests de novo renal transplant patients can safely receive a treatment regimen of either full or reduced exposure CsA in combination with EC-MPS, corticosteroids and basiliximab, with no apparent difference in efficacy or graft function during the first year after transplant.

Aim Mycophenolate mofetil has proven efficacy in the prophylaxis of acute rejection in solid organ transplantation; however, gastrointestinal intolerance can risk this efficacy because of associated dose adjustments and discontinued treatment. Enteric-coated mycophenolate sodium has demonstrated improved gastrointestinal tolerability, but the data in Asian subjects are scarce. Methods This was a Phase-IIIb, open-label, single-arm, multicentre, prospective 6-month study which investigated safety and graft function in stable maintenance renal transplant recipients of Asian origin, after switching from mycophenolate mofetil to enteric-coated mycophenolate sodium at least 3 months after transplantation. Primary end-points included renal allograft function and safety parameters. Results The study recruited patients from 16 centres in Asian countries. The intention-to-treat and safety populations both included 122 patients. Graft function remained stable over the course of the study as measured by creatinine clearance and glomerular filtration rate. At 6 months the incidence of any gastrointestinal adverse events was 20.5% (n = 25), none of which required dose adjustments. There were only three cases of biopsy proven acute rejection with no reports of graft loss or death. Conclusion This study demonstrated that enteric-coated mycophenolate sodium is a safe and effective alternative to mycophenolate mofetil in Asian kidney transplant recipients.

Mycophenolate drug levels are decreased by co-administration of cyclosporine. However, mycophenolate levels may be associated with insufficient immunosuppression. We investigated the pharmacokinetics of 720 mg mycophenolate sodium (EC-MPS) and inosine monophosphate dehydrogenase (IMPDH) activity under co-medication with cyclosporine and steroids within the first 30 d after kidney transplantation (n = 24). Blood samples were drawn at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, and 12 h after the morning dose. Plasma concentrations of mycophenolic acid, its glucuronide metabolites (MPAG; AcMPAG), and free MPA were determined using validated HPLC-DAD. IMPDH activity in leukocytes was analyzed chromatographically. Only six of 24 patients had an MPA-AUC(12h) within the putative therapeutic range of 40-60 mg/L·h. MPA clearance was high with 29 L/h. fMPA-AUC(12h) (r = -0.429, p = 0.04) and MPAG-AUC(12h) correlated significantly with the glomerular filtration rate, while total MPA did not. The MPAG-AUC(12h) was about 52-fold higher than the corresponding values for MPA, whereas the AcMPAG-AUC(12h) reached about 20.4% of the respective MPA-AUC(12h.) We found significant correlations between IMPDH inhibition and MPA concentration (r = -0.665; p < 0.0001), fMPA (r = -0.446; p = 0.003), and AcMPAG (r = -0.459; p = 0.002) but not with MPAG. Only 25% of the patients attained the therapeutic range for MPA-AUC under standard EC-MPS dose during the early-phase post-transplantation. We recommend that EC-MPS should be given in higher doses (3 × 720 mg) in the early post-transplant period when co-administered with cyclosporine.

Tedesco-Silva H, Felipe CR, Park SI, Pinheiro-Machado PG, Garcia R, Slade A, Schmouder R, Medina-Pestana JO. Randomized crossover study to assess the inter- and intrasubject variability of morning mycophenolic acid concentrations from enteric-coated mycophenolate sodium and mycophenolate mofetil in stable renal transplant recipients. Clin Transplant 2010: 24: E116–E123. © 2009 John Wiley & Sons A/S. Abstract: The delayed release of mycophenolic acid (MPA) from enteric-coated mycophenolate sodium (EC-MPS, myfortic®) may have an impact on the variability of MPA trough (C0 h) levels. A randomized, two-period crossover study was performed in 24 maintenance renal transplants to evaluate the inter- and intrasubject variability of MPA predose levels from EC-MPS and mycophenolate mofetil (MMF, CellCept®), both in combination with cyclosporine. Patients received EC-MPS (720 mg b.i.d.) and MMF (1000 mg b.i.d.) for a period of 21 d each. MPA plasma levels were measured over the final seven consecutive days at −1, 0, 1, 2, and 3 h after the morning MPA dose. Intersubject coefficients of variation (%CV) for MPA troughs were 47.5% (95% CI, 34.1–80.3) and 54.4% (40.0–86.8) for EC-MPS and MMF, respectively; intrasubject %CVs were 62.7% (55.1–72.9) and 42.8% (37.9–49.2). High MPA C0 h levels >10 μg/mL were rarely observed with both EC-MPS (1.8%) and MMF (0.6%). Mean MPA area under the curve (AUC)0–3 h was comparable between treatments, while MPA C0 h was on average 46% higher with EC-MPS. In conclusion, predose MPA trough level monitoring appears of limited value during EC-MPS and MMF therapy given the large intrasubject variability in MPA C0 h levels with both treatments.

The influence of pantoprazole 40 mg twice daily on the bioavailability of a single dose of mycophenolate mofetil 1000 mg or enteric-coated mycophenolate sodium is investigated in healthy volunteers. The plasma concentrations of mycophenolic acid and of the inactive metabolite mycophenolic acid glucuronide are measured by high-performance liquid chromatography. The pharmacokinetic parameters following sole administration are similar for mycophenolate mofetil and enteric-coated mycophenolate sodium except for the time to peak concentration, which is longer in the enteric-coated mycophenolate sodium group. Concomitant treatment with pantoprazole significantly (P < .001) lowers the mycophenolic acid exposure following administration of mycophenolate mofetil. The peak concentrations drop by 57%, and area under the curve decreases from 0 to 12 hours by 27%. In contrast, pantoprazole does not change the pharmacokinetics of enteric-coated mycophenolate sodium. Given that mycophenolic acid exposure correlates with the incidence of biopsy-proven acute rejections in renal transplant recipients, these findings may have clinical implications. Administration of pantoprazole in combination with mycophenolate mofetil could possibly result in an insufficient mycophenolic acid exposure, increasing the risk of treatment failure.

Mycophenolic acid (MPA) dose reduction is associated with increased risk of rejection and graft loss in renal transplantation. This analysis investigated the impact of MPA dose changes with enteric-coated mycophenolate sodium (EC-MPS) or mycophenolate mofetil (MMF) in de novo heart transplant recipients. In a 12-month, single-blind trial, 154 patients (EC-MPS, 78; MMF, 76) were randomized to either EC-MPS (1080 mg bid) or MMF (1500 mg bid) in combination with cyclosporine and steroids. The primary efficacy variable was the incidence of treatment failure, comprising a composite of biopsy-proven (BPAR) and treated acute rejection, graft loss or death. Significantly fewer patients receiving EC-MPS required > or =2 dose reductions than patients on MMF (26.9% vs. 42.1% of patients, p = 0.048). Accordingly, the average daily dose of EC-MPS as a percentage of the recommended dose was significantly higher than for MMF (88.4% vs. 79.0%, p = 0.016). Among patients requiring > or =1 dose reduction, the incidence of treated BPAR grade > or =3A was significantly lower with EC-MPS compared with MMF (23.4% vs. 44.0%, p = 0.032). These data suggest that EC-MPS-treated heart transplant patients are less likely to require multiple dose reductions than those on MMF which may be associated with a significantly lower risk of treated BPAR > or =3A.

This study aims to characterize the pharmacokinetics of mycophenolic acid (MPA) and its glucuronide metabolite (mycophenolic acid 7-O-glucuronide, MPAG) following single oral administration of enteric-coated mycophenolate sodium (EC-MPS, myfortic) at an approximate dose level of 450 mg/m(2) body surface area (BSA) to 25 stable renal transplant recipients (aged 5-16 yr), and to evaluate the safety and tolerability of EC-MPS in this pediatric population. Patients had been maintained on a cyclosporine emulsion, Neoral-based immunosuppressive regimen for at least 3 months and had received their first or second renal transplant more than 6 months prior to entry into the study. After a brief lag phase (t(lag) 0.75 h), MPA was rapidly absorbed (t(max) 2.5 h) and rapidly converted to MPAG (t(max) 3.25 h), with relatively high plasma concentrations of MPAG (C(max) 67.7 microg/mL) compared with MPA (C(max) 36.3 microg/mL). The elimination half-life for MPAG was slightly longer than for MPA (approximately 13 h vs. 8.5 h), and the apparent oral clearance of MPA was approximately 0.2 L/h/kg. The pharmacokinetics of MPA or MPAG were not affected by age, body weight or BSA, within the study population. The pharmacokinetic results for pediatric patients are comparable with those obtained previously in adults, although exposure based on AUC(0-infinity) was approximately 23% higher, and this finding may be a result of dosing on the basis of BSA, rather than body weight. The recommended dose of EC-MPS in pediatric patients is 400-450 mg/m(2) twice daily or, alternatively, approximately 10-14 mg/kg twice daily when used in combination with cyclosporine microemulsion.

Morbidity and mortality resulting from acute and subsequently chronic graft-versus-host disease (GVHD) pose a serious challenge to wider applicability of allogeneic stem cell transplantation (SCT). Mycophenolate mofetil (MMF) is a widely used drug in combination with a calcineurin inhibitor and often cyclosporine (CsA), in preventing GVHD. The use of MMF for acute GVHD (aGVHD) prophylaxis appears to result in significantly faster platelet engraftment and a lower incidence of severe mucositis compared to methotrexate, which could reduce the length of hospital stay. However, there is no statistically significant difference between MMF and methotrexate in regards to relapse risk, non-relapse mortality, or overall survival(1) . This article is protected by copyright. All rights reserved. (Less)

To date, the best results in life-supporting pig-to-primate renal xenotransplantation have been obtained in recipients exposed to long-term immunosuppression with cyclophosphamide. As this agent is frequently associated with side-effects, we have explored the potential of a mycophenolate sodium-based maintenance immunosuppression in this model. Human decay-accelerating factor (hDAF) transgenic kidneys were transplanted into splenectomized and bilaterally nephrectomized cynomolgus monkeys immunosuppressed with mycophenolate sodium, cyclosporin A and steroids, and exposed to a brief induction course with cyclophosphamide (up to four doses). After transplantation, the primates were monitored daily for biochemical and haematological evaluations and for the measurements of haemolytic anti-pig antibodies (APA). A detailed histological analysis of each explanted graft was also performed. All the animals showed very poor initial graft function but survived for up to 51 days. In contrast to our previous studies in xenograft recipients on long-term immunosuppression with cyclophosphamide, minimal or no circulating xeno-directed antibodies, as measured by the evaluation of APA titres, were detected in this series although some degree of acute humoral rejection was observed in all the explanted grafts and was the primary cause of graft failure. Furthermore, in addition to areas of humorally mediated graft damage, we have observed for the first time areas with exclusive and prominent infiltration by CD2+ and CD8+ mononuclear cells presenting patterns compatible with tubulitis, glomerulitis and arteritis, which we have called acute cellular xenograft rejection (ACXR). In addition, CD68+ infiltrating macrophages and CD20+ B-cells were also present. This study demonstrates that a triple maintenance immunosuppression with mycophenolate sodium, cyclosporin A and steroids is a viable alternative to a cyclophosphamide-based immunosuppression to obtain prolonged survival of porcine organs transplanted into primates. However, a more stringent control of antibody forming cells remains essential to further extend the survival of xenografts in this model. In addition, the use of the immunosuppressive regimen reported here in the primate is associated with the occurrence of a new category of cell-mediated xenograft injury (ACXR) whose significance has yet to be clarified.

Background Pemphigus is a chronic immunobullous disease, characterized by formation of blisters and erosions in skin and/or mucous membranes. This severe disease requires systemic immunosuppressive therapy. However, some patients are refractory, and long-term use of immunosuppressive agents can cause serious side-effects. Mycophenolic acid is increasingly being used as a corticosteroid-sparing agent or as monotherapy in immunosuppressive regimens. Objectives We aimed to evaluate the effectiveness of mycophenolate sodium, a sodium salt of mycophenolic acid, in the treatment of pemphigus vulgaris. Methods Six patients who were diagnosed as pemphigus vulgaris with active, refractory disease were treated with mycophenolate sodium. Three patients received mycophenolate sodium monotherapy; three patients received mycophenolate in combination with steroid. All patients were monitored regularly. Results Mycophenolate sodium was well tolerated with a similar efficacy of mycophenolate mofetil, and no side-effects have been observed. Conclusions Mycophenolate sodium appears to be an effective and safe alternative in the treatment of pemphigus vulgaris.