title: Combining cytochrome P-450 3A4 modulators and cyclosporine or everolimus in transplantation is successful.
abstract: OBJECTIVE
  To describe the long term follow-up of kidney allograft recipients receiving ketoconazole with calcineurin inhibitors (CNI) alone or combined with everolimus.
  
  
  METHODS
  This is an open-label, prospective observational clinical trial in low immunologic risk patients who, after signing an Institutional Review Board approved consent form, were included in one of two groups. The first one (n = 59) received everolimus (target blood level, 3-8 ng/mL) and the other (n = 114) azathioprine 2 mg/kg per day or mycophenolate mofetyl (MMF) 2 g/d. Both groups also received tapering steroids, the cytochrome P-450 3A4 (CYP3A4) modulator, ketoconazole 50-100 mg/d, and cyclosporine with C0 targets in the everolimus group of 200-250 ng/mL in 1 mo, 100-125 ng/mL in 2 mo, and 50-65 ng/mL thereafter, and in the azathioprine or MMF group of 250-300 ng/mL in 1 mo, 200-250 ng/mL in 2 mo, 180-200 ng/mL until 3-6 mo, and 100-125 ng/mL thereafter. Clinical visits were performed monthly the first year and quarterly thereafter by treating physicians and all data was extracted by the investigators.
  
  
  RESULTS
  The clinical characteristics of these two cohorts were similar. During the follow up (66 + 31 mo), both groups showed comparable clinical courses, but the biopsy proven acute rejection rate during the full follow-up period seemed to be lower in the everolimus group (20% vs 36%; P = 0.04). The everolimus group did not show a higher surgical complication rate than the other group. By the end of the follow-up period, the everolimus group tended to show a higher glomerular filtration rate. Nevertheless, we found no evidence of a consistent negative slope of the temporal allograft function estimated by the modification of the diet in renal disease formula in any of both groups. At 6 years of follow-up, the uncensored and death-censored graft survivals were 91% and 93%, and 91% and 83% in the everolimus plus cyclosporine, and cyclosporine alone groups, respectively. The addition of ketoconazole saved 80% of cyclosporine and 56% of everolimus doses.
  
  
  CONCLUSIONS
  Combining CYP3A4 modulators with CNI or mammalian target of rapamycin inhibitor, in low immunological risk kidney transplant recipients is feasible, effective, safe and affordable even in the long term.
authors.affiliation: Fernando González, Ricardo Valjalo, Department of Nephrology, Faculty of Medicine, Universidad de Chile, Hospital del Salvador, Santiago 7500922, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: González
authors.affiliation: Fernando González, Ricardo Valjalo, Department of Nephrology, Faculty of Medicine, Universidad de Chile, Hospital del Salvador, Santiago 7500922, Chile.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Valjalo
keywords: Cyclosporine; Cytochrome P-450; Cytochrome P-450 3A4 modulator; Everolimus; Immunosuppressive; Ketoconazole; Kidney transplant