Postmarketing evaluation of mycophenolate mofetil-based triple therapy immunosuppression compared with a conventional azathioprine-based regimen reveals enhanced efficacy and early pharmacoeconomic benefit after renal transplantation

Intragraft transcriptional profiling of renal transplant patients with tubular dysfunction reveals mechanisms underlying graft injury and recovery

Background

Proximal tubular dysfunction (PTD) is associated with a decreased long-term graft survival in renal transplant patients and can be detected by the elevation of urinary tubular proteins. This study investigated transcriptional changes in biopsies from renal transplant patients with PTD to disclose molecular mechanisms underlying graft injury and functional recovery.

Methods

Thirty-three renal transplant patients with high urinary levels of retinol-binding protein, a biomarker of PTD, were enrolled in the study. The initial immunosuppressive scheme included azathioprine, cyclosporine, and steroids. After randomization, 18 patients (group 2) had their treatment modified by reducing cyclosporine dosage and substituting azathioprine for mycophenolate mofetil, while the other 15 patients (group 1) remained under the initial scheme. Patients were biopsied at enrollment and after 12 months of follow-up, and paired comparisons were performed between their intragraft gene expression profiles. The differential transcriptome profiles were analyzed by constructing gene co-expression networks and identifying enriched functions and central nodes in each network.

Results

Only the alternative immunosuppressive scheme used in group 2 ameliorated renal function and tubular proteinuria after 12 months of follow-up. Intragraft molecular changes observed in group 2 were linked to autophagy, extracellular matrix, and adaptive immunity. Conversely, gene expression changes in group 1 were related to fibrosis, endocytosis, ubiquitination, and endoplasmic reticulum stress.

Conclusion

These results suggest that molecular networks associated with the control of endocytosis, autophagy, protein overload, fibrosis, and adaptive immunity may be involved in improvement of graft function.

Electronic supplementary material

The online version of this article (doi:10.1186/s40246-015-0059-6) contains supplementary material, which is available to authorized users.

Update on Pharmacoeconomics in Transplantation

Purpose

To provide current information on pharmacoeconomic outcomes in transplantation for the past 6 years.

Methods

An extensive literature search was undertaken using PubMed and other authenticated Internet sources. Key words used to elicit pertinent studies were “pharmacoeconomics,” “transplantation,” “cost-effectiveness,” “cost-benefit,” “cost-minimization” and “cost-utility” analyses. Studies included in the review contain updated pharmacoeconomic data generated during the past 6 years on economic, clinical, and humanistic outcomes. These data are used to describe and analyze the cost of drug therapy used in transplantation.

Results

Background information is included in the review to provide a context from which to evaluate new study material. Data extracted from the studies include significant findings and study limitations. Data were stratified into understanding pharmacoeconomic methods and their application to transplantation, maintenance and induction therapies, and management of and costs associated with adverse events and quality-of-life issues.

Conclusions

Continued evolution of pharmacoeconomic analysis is needed so that optimal care can be provided in the most cost-effective manner. Pharmacoeconomic study, done rationally and logically, is an indispensable tool in determining optimal transplantation regimens.

Mycophenolate mofetil: a pharmacoeconomic review of its use in solid organ transplantation

Most pharmacoeconomic studies of mycophenolate mofetil have focused on its use as part of maintenance immunosuppression for renal transplantation, involving short-term (3 to 12 months) time frames. In general, mycophenolate mofetil reduced the treatment costs for rejection episodes and graft failure which offset its higher drug acquisition cost compared with azathioprine. Several cost analyses have been modelled on the large multicentre trials of adult renal transplant recipients. The use of mycophenolate mofetil was associated with either cost savings or no additional costs after 6 or 12 months in French, US and Canadian analyses of triple or quadruple immunosuppressant therapy. A further cost analysis utilising a registry database of renal transplant recipients in the US found mycophenolate mofetil to be cost saving compared with azathioprine after 6.4 years when evaluating costs due to graft loss only. Of the limited cost-effectiveness analyses with the drug, one US study modelled the 1- and 10-year cost effectiveness of mycophenolate mofetil and various other immunosuppressants used in combined regimens. Long-term use of mycophenolate mofetil was less cost effective than other regimens, but the use of long-term mycophenolate mofetil in high-risk patients was shown to be a relatively cost-effective strategy. In another US analysis comparing mycophenolate mofetil with azathioprine as part of quadruple therapy, mycophenolate mofetil was associated with slightly lower costs during the first year after renal transplantation as well as improved clinical outcomes.

CONCLUSION

Pharmacoeconomic studies support the use of mycophenolate mofetil as part of immunosuppressant therapy in renal transplantation, at least in the short term. Although the cost effectiveness of mycophenolate mofetil in the long term is less clear, limited pharmacoeconomic data available appear promising. Among issues to be examined in future economic analyses in renal transplantation are the calcineurin-sparing potential of mycophenolate mofetil and the feasibility of using more efficient mycophenolate mofetil dosage regimens when using the drug on a long-term basis. Additional pharmacoeconomic analyses of mycophenolate mofetil are also needed in other types of solid organ transplantation.

A controlled trial comparing two doses of cyclosporine in conjunction with mycophenolate mofetil and corticosteroids

It is unknown whether the addition of mycophenolate mofetil (MMF) to cyclosporine (CsA) and prednisone after renal transplantation (RTx) allows for a reduced dose of CsA, to minimize the incidence of CsA-related side effects and to reduce costs. Therefore, 313 renal allograft recipients were randomized for treatment with MMF (1000 mg twice a day), prednisone, and either conventional- or low-dose CsA during the first 3 mo after RTx. The target trough levels were 300 and 150 ng/ml, respectively, during the first 3 mo and 150 ng/ml in both groups thereafter. A total of 313 patients were included: 161 patients received a conventional dose and 152 received a low dose of CsA. During the first 6 mo after RTx, graft failure or patient death occurred in 19 of 161 patients (12%) in the conventional-dose group and in 11 of 152 patients (7%) in the low-dose group (not significant). Biopsy-proven acute rejection occurred in 36 of 161 patients (22%) in the conventional-dose group and in 29 of 152 patients (19%) in the low-dose group (not significant). The incidence of delayed graft function was similar in both groups (31 of 161 [19%] versus 28 of 152 [18%]; not significant). Serum creatinine did not differ between the conventional- and the low-dose groups: 151 +/- 56 micromol/L versus 142 +/- 49 micromol/L at 3 mo and 141 +/- 60 micromol/L versus 136 +/- 49 micromol/L at 6 mo. There were no differences between the groups regarding BP, lipid metabolism, and infectious complications. In the low-dose group, an estimated $500 per patient was saved on the costs of CsA. In conclusion, the addition of MMF to CsA and prednisone after RTx allows the use of a lower-than-conventional dose of CsA, without increasing the risk of rejection.