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Regional transplant practices may affect clinical outcomes within multinational studies. This study evaluated whether the overall results from the Symphony study can be generalized to the participating countries. De novo adult renal transplant recipients (n = 1645) were randomized to receive standard-dose cyclosporine, or daclizumab induction plus low-dose cyclosporine, low-dose tacrolimus,or low-dose sirolimus, all in addition to mycophenolate mofetil and steroids. Data for the highest patient-recruiting countries, Spain (n = 275),Germany (n = 316) and Turkey (n = 258), were compared. Patient transplant characteristics were different among the country subsets; only deceased donors in Spain, more expanded criteria donors in Germany, and mainly living donors in Turkey. Efficacy results for the three countries were consistent with that of the overall study - renal function and biopsy-proven acute rejection (BPAR)rates were superior with low-dose tacrolimus. Turkey had higher mean calculated glomerular filtration rate across all treatment groups (60.6-72.2 ml/min)compared with that of Spain (51.1-57.5 ml/min) and Germany (51.3-62.9 ml/min). Spain and Turkey had lower BPAR rates across the four treatment groups compared with the overall study; Germany had much higher rates(21.0-54.2%). These findings confirm the general applicability of the Symphony study results and highlight the importance of inclusion of patients from different geographic origins in randomized clinical trials.

Cyclosporine (CsA) is a critical-dose drug for which a minor change in absorption can have important clinical implications. Generic formulations of CsA are becoming more widely available, but standard criteria for bioequivalence require only that a single study in healthy volunteers demonstrate that mean pharmacokinetic parameters fall within 80-125% of the mean values for Neoral, the reference formulation of CsA. However, CsA absorption is known to differ between healthy volunteers and transplant patients and between different types of transplant patients, such that standard bioequivalence testing may be inadequate to ensure interchangeability of CsA formulations in all patients. The limited available clinical evidence has shown that stable renal transplant patients receiving Neoral have a significant reduction in mean CsA trough level after transfer to the Cicloral formulation. Mean pharmacokinetic values have been reported as equivalent following transfer to Gengraft in one study, but mean CsA trough fell and mean serum creatinine rose significantly in a separate trial. The only clinical outcomes data available are from a retrospective study of de novo renal transplant patients, which reported a significantly higher incidence of biopsy-proven acute rejection in patents receiving Gengraf versus Neoral (39% versus 25%, P<0.05). Until robust clinical data demonstrate that different formulations of CsA are interchangeable, it is advisable to prescribe CsA by brand, and any transfer to a different CsA formulation should be undertaken with close supervision and only at the direction of the transplant physician.

Frei U, Daloze P, Vítko Š, Klempnauer J, Reyes-Acevedo R, Titiz I, Fricke L, Bernasconi C, Ekberg H. Acute rejection in low-toxicity regimens: clinical impact and risk factors in the Symphony study. Clin Transplant 2010: 24: 500–509. © 2009 John Wiley & Sons A/S. The Symphony study assessed whether mycophenolate mofetil (MMF)-based regimens containing reduced doses of adjunct immunosuppressants could reduce toxicity while maintaining efficacy. Here, we examined the impact of acute rejection and associated risk factors. The incidence of biopsy-proven acute rejection in the low-dose tacrolimus group was approximately half that of the standard-dose cyclosporine and low-dose cyclosporine groups, and a third of that in the low-dose sirolimus group. The low-dose cyclosporine group had more severe rejection episodes (≥grade II) compared with other groups. Acute rejection was associated with a 10 mL/min glomerular filtration rate (GFR) reduction and a 5.3% absolute increase in graft loss at 12 months. Overall, the highest GFR was found in both rejecters and non-rejecters receiving low-dose tacrolimus, both in an intent-to-treat analysis and in patients successfully treated according to the protocol. In Cox regression models, human leukocyte antigen (HLA) mismatches and expanded criteria donors increased the acute rejection risk, while recipient age, living related donor, and MMF dose were associated with a reduced risk. Acute rejection was associated with worse outcome but did not entirely explain the differences among the treatment groups. The 2 g MMF plus low-dose tacrolimus combination appears to be the most efficient of all regimens examined regardless of acute rejection. [ABSTRACT FROM AUTHOR]