Optimal Everolimus Concentration Is Associated With Risk Reduction for Acute Rejection in De Novo Renal Transplant Recipients

Background: Everolimus (Evl) plus tacrolimus (Tac) in de novo renal transplantation is effective and safe. Whether the concentration of Evl affects efficacy and safety in a Tac-based regimen has not been previously reported. AIM: To evaluate whether the concentration of Evl affects biopsy-proven acute rejection (BPAR), renal function, adverse events (AEs); and to assess for pharmacokinetic (PK) interactions. Methods: Data were from a prospective, multicenter, open-label, randomized, exploratory 6-month study of 92 renal transplant patients treated de novo with concentration-controlled Evl (target trough levels 3 ng/mL) plus low-dose Tac or Evl plus standard-dose Tac; both groups received basiliximab and corticosteroids. Data were pooled across study arms to examine BPAR rates in patients with Evl trough levels less than 3 (n=26), 3 to 8 (n=62), or more than 8 ng/mL (n=4). Groups were stratified by both Evl and Tac trough levels to evaluate glomerular filtration rate and AEs. Evl and Tac PK interactions were evaluated in a subset of 14 patients. Results: Evl trough level of more than or equal to 3 ng/mL was associated with significantly lower rates of BPAR as compared with a trough level of less than 3 ng/mL. Glomerular filtration rate was similar at 6 months for both the low and standard Tac groups. No apparent PK interactions were observed between Evl and Tac. AEs were infrequent and did not seem to be associated with the Evl or Tac level. ConclusionS: Evl trough levels 3 ng/mL plus Tac are associated with low rates of BPAR without adversely affecting renal function. No evident PK interaction exists between Evl and Tac. Copyright © 2010 by Lippincott Williams & Wilkins.