Reduction of site-specific CYP3A-mediated metabolism for dual angiotensin and endothelin receptor antagonists in various in vitro systems and in cynomolgus monkeys.
2-{Butyryl-[2'-(4,5-dimethyl-isoxazol-3-ylsulfamoyl)-biphenyl-4-ylmethyl]-amino}-N-isopropyl-3-methyl-butyramide (BMS-1) is a potent dual acting angiotensin-1 and endothelin-A receptor antagonist. The compound was subject to rapid metabolic clearance in monkey and human liver microsomes and exhibited low systemic exposure and marked interanimal variability in cynomolgus monkeys after p.o. administration. The variability pattern was identical to that of midazolam given p.o. in the same monkeys, as measured by area under the curve and Cmax values, suggesting that CYP3A-mediated metabolism might play a role in the rapid clearance and observed interanimal variability. Subsequent in vitro metabolism studies using human liver microsomes and cDNA-expressed human cytochrome P450 (P450) enzymes revealed that BMS-1 was a CYP3A4 substrate and was not metabolized by other human P450 enzymes. Mass spectral and NMR analyses of key metabolites led to the identification of the dimethyl isoxazole group as a major metabolic soft spot for BMS-1. Replacement of the 4-methyl group on the isoxazole ring with halogens not only improved overall metabolic stability but also decreased CYP3A-mediated hydroxylation of the isoxazole 5-methyl group. As exemplified by 2-{butyryl-[2'-(4-fluoro-5-methyl-isoxazol-3-ylsulfamoyl)-biphenyl-4-ylmethyl]-amino}-N-isopropyl-3-methyl-butyramide (BMS-3), a fluorinated analog of BMS-1, the structural modification resulted in an increase in the systemic exposure relative to previous analogs and a dramatic reduction in interanimal variability in the monkeys after p.o. administration. In addition, BMS-3 could be metabolized by both CYP2C9 and CYP3A4, thus avoiding the reliance on a single P450 enzyme for metabolic clearance. Integration of results obtained from in vitro metabolism studies and in vivo pharmacokinetic evaluations enabled the modulation of site-specific CYP3A-mediated metabolism, yielding analogs with improved overall metabolic profiles.
Zhang
Hongjian
H
Metabolism and Pharmacokinetics, Pharmaceutical Research Institute, Bristol-Myers Squibb Company, P.O. Box 4000, Princeton, NJ 08543, USA. hongjian.zhang@bms.com
Zhang
Donglu
D
Li
Wenying
W
Yao
Ming
M
D'Arienzo
Celia
C
Li
Yi-Xin
YX
Ewing
William R
WR
Gu
Zhengxiang
Z
Zhu
Yeheng
Y
Murugesan
Natesan
N
Shyu
Wen-Chyi
WC
Humphreys
W Griffith
WG
D000577:Amides / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D065130:Endothelin A Receptor Antagonists; D018757:GABA Modulators / Q000378:metabolism / Q000493:pharmacokinetics; D006801:Humans; D006900:Hydroxylation; D007555:Isoxazoles / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D008252:Macaca fascicularis; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D008874:Midazolam / Q000378:metabolism / Q000493:pharmacokinetics; D015394:Molecular Structure; D013449:Sulfonamides / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D053719:Tandem Mass Spectrometry
C523298:2-(butyryl-(2'-(4,5-dimethylisoxazol-3-ylsulfamoyl)biphenyl-4-ylmethyl)amino)-N-isopropyl-3-methylbutyramide; C523299:2-(butyryl-(2'-(4-chloro-5-methylisoxazol-3-ylsulfamoyl)biphenyl-4-ylmethyl)amino)-N-isopropyl-3-methylbutyramide; C523300:2-(butyryl-(2'-(4-fluoro-5-methylisoxazol-3-ylsulfamoyl)biphenyl-4-ylmethyl)amino)-N-isopropyl-3-methylbutyramide; D000577:Amides; D057911:Angiotensin Receptor Antagonists; D065130:Endothelin A Receptor Antagonists; D018757:GABA Modulators; D007555:Isoxazoles; D013449:Sulfonamides; D003577:Cytochrome P-450 Enzyme System; C006866:butyramide; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D008874:Midazolam