Effect of CYP3A4*22, CYP3A5*3, and CYP3A Combined Genotypes on Cyclosporine, Everolimus, and Tacrolimus Pharmacokinetics in Renal Transplantation

<jats:p>Cyclosporine, everolimus, and tacrolimus are the cornerstone of immunosuppressive therapy in renal transplantation. These drugs are characterized by narrow therapeutic windows, highly variable pharmacokinetics (PK), and metabolism by CYP3A enzymes. Recently, the decreased activity allele, <jats:italic>CYP3A4*22</jats:italic>, was described as a potential predictive marker for CYP3A4 activity. This study investigated the effect of <jats:italic>CYP3A4*22</jats:italic>, <jats:italic>CYP3A5*3</jats:italic>, and <jats:italic>CYP3A</jats:italic> combined genotypes on cyclosporine, everolimus, and tacrolimus PK in renal transplant patients. <jats:italic>CYP3A4*22</jats:italic> carriers showed a significant lower clearance for cyclosporine (−15%), and a trend was observed for everolimus (−7%) and tacrolimus (−16%). Patients carrying at least one <jats:italic>CYP3A5*1</jats:italic> allele had 1.5‐fold higher tacrolimus clearance compared with noncarriers; however, <jats:italic>CYP3A5*3</jats:italic> appeared to be nonpredictive for everolimus and cyclosporine. <jats:italic>CYP3A</jats:italic> combined genotype did not significantly improve prediction of clearance compared with <jats:italic>CYP3A5*3</jats:italic> or <jats:italic>CYP3A4*22</jats:italic> alone. These data suggest that dose individualization of cyclosporine, everolimus, or tacrolimus therapy based on <jats:italic>CYP3A4*22</jats:italic> is not indicated.</jats:p><jats:p><jats:italic>CPT: Pharmacometrics Systems Pharmacology</jats:italic> (2014); 3, e100; doi:<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" xlink:href="10.1038/psp.2013.78">10.1038/psp.2013.78</jats:ext-link>; published online 12 February 2014</jats:p>