Nonclinical pharmacokinetics and metabolism of EPZ‐5676, a novel DOT1L histone methyltransferase inhibitor. (14th February 2014)

• Record Type: Journal Article
• Authors: Basavapathruni, Aravind; Olhava, Edward J.; Daigle, Scott R.; Therkelsen, Carly A.; Jin, Lei; Boriack‐Sjodin, P. Ann; Allain, Christina J.; Klaus, Christine R.; Raimondi, Alejandra; Scott, Margaret Porter; Dovletoglou, Angelos; Richon, Victoria M.; Pollock, Roy M.; Copeland, Robert A.; Moyer, Mikel P.; Chesworth, Richard; Pearson, Paul G.; Waters, Nigel J.
• Is Part Of: Biopharmaceutics & drug disposition. Volume 35:Number 4(2014:May)
• Page Start: 237
• Page End: 252
• Publication Date: 2014-02-14
• Subjects: Biopharmaceutics -- Periodicals; Drugs -- Metabolism -- Periodicals; Pharmacology -- Periodicals; Biopharmaceutics -- Periodicals; Pharmaceutical Preparations -- metabolism -- Periodicals; 615.19
• DOI: 10.1002/bdd.1889
• Languages: English
• ISSNs: 0142-2782

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>(2<italic>R</italic>, 3<italic>R</italic>, 4<italic>S</italic>, 5<italic>R</italic>)‐2‐(6‐Amino‐9<italic>H</italic>‐purin‐9‐yl)‐5‐((((1<italic>r</italic>, 3<italic>S</italic>)‐3‐(2‐(5‐(<italic>tert</italic>‐butyl)‐1<italic>H</italic>‐benzo[<italic>d</italic>]imidazol‐2‐yl)ethyl)cyclobutyl)(isopropyl)amino)methyl)tetrahydrofuran‐3, 4‐diol (EPZ‐5676) is a novel DOT1L histone methyltransferase inhibitor currently in clinical development for the treatment of MLL‐rearranged leukemias. This report describes the preclinical pharmacokinetics and metabolism of EPZ‐5676, an aminonucleoside analog with exquisite target potency and selectivity that has shown robust and durable tumor growth inhibition in preclinical models. The <italic>in vivo</italic> pharmacokinetics in mouse, rat and dog were characterized following i.v. and p.o. administration; EPZ‐5676 had moderate to high clearance, low oral bioavailability with a steady‐state volume of distribution 2–3 fold higher than total body water. EPZ‐5676 showed biexponential kinetics following i.v. administration, giving rise to a terminal elimination half‐life (<italic>t</italic><sub>1/2</sub>) of 1.1, 3.7 and 13.6 h in mouse, rat and dog, respectively. The corresponding <italic>in vitro</italic> ADME parameters were also studied and utilized for <italic>in vitro–in vivo</italic> extrapolation purposes. There was good agreement between the microsomal clearance and the <italic>in vivo</italic> clearance implicating hepatic oxidative metabolism as the predominant elimination route in preclinical species. Furthermore, low renal clearance was observed in mouse, approximating to <italic>f</italic><sub>u</sub>‐corrected glomerular filtration rate (GFR) and thus passive glomerular filtration. The metabolic pathways across species were studied in liver microsomes in which EPZ‐5676 was metabolized to three monohydroxylated metabolites (M1, M3 and M5), one <italic>N</italic>‐dealkylated product (M4) as well as an <italic>N</italic>‐oxide (M6). Copyright © 2014 John Wiley & Sons, Ltd.</p> </abstract>