Efficacy and safety of enteric-coated mycophenolate sodium in de novo and maintenance renal transplant patients

Cell Therapy in Solid Organ Transplantation

Transplantation is the only cure for end-stage organ failure. Current immunosuppressive drugs have two major limitations: 1) non antigen specificity, which increases the risk of cancer and infection diseases, and 2) chronic toxicity. Cell therapy appears to be an innovative and promising strategy to minimize the use of immunosuppression in transplantation and to improve long-term graft survival. Preclinical studies have shown efficacy and safety of using various suppressor cells, such as regulatory T cells, regulatory B cells and tolerogenic dendritic cells. Recent clinical trials using cellbased therapies in solid organ transplantation also hold out the promise of improving efficacy. In this review, we will briefly go over the rejection process, current immunosuppressive drugs, and the potential therapeutic use of regulatory cells in transplantation.

Pharmacokinetic characteristics of enteric-coated mycophenolate sodium in liver transplant recipients early after transplantation

AIM: To investigate the pharmacokinetics of enteric-coated mycophenolate sodium (EC-MPS) in liver transplant recipients early after transplantation.

METHODS: Twenty-five liver transplant recipient received tacrolimus and EC-MPS (720 mg, twice daily). Mycophenolic acid (MPA) concentrations were measured by high performance liquid chromalography (HPLC) before dosing (C_{0 h}) and at 0.5 h (C_{0.5 h}), 1 h (C_{1 h}), 1.5 h (C_{1.5 h}), 2 h (C_{2 h}), 4 h (C_{4 h}), 6 h (C_{6 h}), 8 h (C_{8 h}), 10 h (C_{10 h}), and 12 h (C_{12 h}) after dosing between days 7 and 21 postoperatively. Meanwhile, trough concentration (C_{0 h}) of FK506, hepatic and renal function and blood cell counts were also measured. The WinNonlin software was used to calculate the area of concentration-time under the curve (AUC).

RESULTS: The average MPA-AUC0-12h was 40.36 (µg•h)/mL ± 17.20 (µg•h)/mL. The C_max was 17.037 mg/L ± 7.632 mg/L, and the T_max was 3.06 h ± 1.50 h. Individual concentrations of MPA-C_{0 h}-C_{12 h} were not significantly related with MPA-AUC_{0-12 h} (r² < 0.75). FK506-C_{0 h}, serum albumin level and Cr-CL were not significantly correlated with MPA-AUC_{0-12 h} (all P > 0.05).

CONCLUSION: The variability of MPA-AUC_{0-12 h} is significant in liver transplant recipients early after transplantation. Single time-point MPA concentration can not reflect MPA-AUC_{0-12 h} effectively. MPA-AUC_{0-12 h} is less influenced by FK506 concentration, serum albumin and creatinine clearance.

Enteric-coated mycophenolate sodium in de novo and maintenance kidney-pancreas transplant recipients

BACKGROUND

Our objective was to describe efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS) in de novo and maintenance recipients of kidney-pancreas transplant in the clinical practice.

METHODS

Observational, multicentre, prospective, 12-month study.

RESULTS

We included 24 de novo and 24 maintenance patients. EC-MPS mean (± SD) doses at initiation in de novo patients were 1440 ± 0 vs. 1268 ± 263 mg/d at month 12 (M12). Patient and renal graft survival at one yr were 100%, and pancreatic graft survival was 83.3% (two losses owing to technical failure and two owing to rejection). In the maintenance cohort, EC-MPS was introduced at a median (P25-P75) of 30 (6-71) months after transplant. Baseline doses were 585 ± 310 vs. 704 ± 243 mg/d at M12. In this group, a significant increase in creatinine clearance was observed (65 ± 22 at baseline vs. 74 ± 20 mL/min at M12, p = 0.011). Patient, renal, and pancreatic graft survival were 100%, 95.8%, and 100%, respectively (one kidney graft loss owing to rejection). During follow-up, one patient from each group discontinued EC-MPS.

CONCLUSIONS

The efficacy of EC-MPS in the clinical practice of kidney-pancreas transplantation is good, with high patient and grafts survival at 12 months, and good safety profile. The maintenance group displayed an improvement in renal function.

The anti-fibrotic effect of mycophenolic acid-induced neutral endopeptidase

Mycophenolic acid (MPA) appears to have anti-fibrotic effects, but the molecular mechanisms underlying this are unknown. We prospectively studied 35 stable kidney transplant recipients maintained on cyclosporine and azathioprine. We converted 20 patients from azathioprine to enteric-coated mycophenolate sodium (EC-MPS) and continued the remaining 15 patients on azathioprine. Exploratory mRNA expression profiling, performed on five randomly selected EC-MPS patients, revealed significant upregulation of neutral endopeptidase (NEP), which is an enzyme that degrades angiotensin II. We confirmed these microarray data by measuring levels of NEP expression in all subjects; in addition, we found that NEP gene expression correlated inversely with proteinuria. In an additional 33 patients, glomerular and tubular NEP protein levels from renal graft biopsies were significantly higher among the 13 patients receiving cyclosporine + EC-MPS than among the 12 patients receiving cyclosporine + azathioprine or 8 patients receiving cyclosporine alone. Glomerular NEP expression inversely correlated with glomerulosclerosis and proteinuria, and tubular NEP expression inversely correlated with interstitial fibrosis. Incubation of human proximal tubular cells with MPA increased NEP gene expression in a dose- and time-dependent manner. Moreover, MPA reduced angiotensin II-induced expression of the profibrotic factor plasminogen activator inhibitor-1, and a specific NEP inhibitor completely reversed this effect. Taken together, our data suggest that MPA directly induces expression of neutral endopeptidase, which may reduce proteinuria and slow the progression of renal damage in kidney transplant recipients.

Efficacy and safety of conversion of mycophenolate mofetil to enteric-coated mycophenolate sodium in Mexican renal transplant children

The aim of the study was to evaluate the efficacy and safety of the conversion of MMF to EC-MPS in pediatric renal transplant recipients. We included 12 patients with stable graft function who were receiving MMF treatment. In the first visit, a complete medical examination was performed, which included a GSRS, a nine-point pharmacokinetic profile, samples for renal, liver and hematological tests and evaluation of IMPDH2 gene expression. The patients were transferred to an equimolar dose of EC-MPS. Two wk later, a clinical evaluation and blood collection, as in the first visit were performed. There was no change in serum creatinine, leukocyte count, serum albumin, or transaminase levels, but we found a statistically significant reduction of hemoglobin after conversion (13.2 +/- 1.6 g/dL with MMF vs. 12.5 +/- 1.3 g/dL when receiving EC-MPS). The GSRS total mean score was 16 +/- 12 with MMF vs. 8 +/- 5 with EC-MPA (p < 0.05). There was no statistically significant difference between formulations in the gene expression of IMPDH 2, in the AUC(0-12h) or in C(max). However, peak concentration occurred later with EC-MPS.