Abstract
Purpose
After single oral dosing of the glycine reuptake transporter (GlyT1) inhibitor, iclepertin (BI 425809), a single major circulating metabolite, M530a, was identified. However, upon multiple dosing, a second major metabolite, M232, was observed with exposure levels ~ twofold higher than M530a. Studies were conducted to characterize the metabolic pathways and enzymes responsible for formation of both major human metabolites.
Methods
In vitro studies were conducted with human and recombinant enzyme sources and enzyme-selective inhibitors. The production of iclepertin metabolites was monitored by LC–MS/MS.
Results
Iclepertin undergoes rapid oxidation to a putative carbinolamide that spontaneously opens to an aldehyde, M528, which then undergoes reduction by carbonyl reductase to the primary alcohol, M530a. However, the carbinolamide can also undergo a much slower oxidation by CYP3A to form an unstable imide metabolite, M526, that is subsequently hydrolyzed by a plasma amidase to form M232. This difference in rate of metabolism of the carbinolamine explains why high levels of the M232 metabolite were not observed in vitro and in single dose studies in humans, but were observed in longer-term multiple dose studies.
Conclusions
The long half-life iclepertin metabolite M232 is formed from a common carbinolamine intermediate, that is also a precursor of M530a. However, the formation of M232 occurs much more slowly, likely contributing to its extensive exposure in vivo. These results highlight the need to employ adequate clinical study sampling periods and rigorous characterization of unexpected metabolites, especially when such metabolites are categorized as major, thus requiring safety assessment.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Data Availability
The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.
References
Rosenbrock H, Desch M, Kleiner O, Dorner-Ciossek C, Schmid B, Keller S, et al. Evaluation of pharmacokinetics and pharmacodynamics of BI 425809, a novel GlyT1 inhibitor: translational studies. Clin Transl Sci. 2018;11:616–23.
Burkard U, Desch M, Shatillo Y, Wunderlich G, Mack SR, Schlecker C, et al. The absolute bioavailability, absorption, distribution, metabolism, and excretion of BI 425809 Administered as an oral dose or an oral dose with an intravenous microtracer dose of [14C]-BI 425809 in healthy males. Clin Drug Invest. 2022;42:87–99.
Hamilton RA, Garnett WR, Kline BJ. Determination of mean valproic acid serum level by assay of a single pooled sample. Clin Pharmacol Amp Ther. 1981;29:408–13.
Mannens G, Huang ML, Meuldermans W, Hendrickx J, Woestenborghs R, Heykants J. Absorption, metabolism, and excretion of risperidone in humans. Drug Metab Dispos Biol Fate Chem. 1993;21:1134–41.
Stiff DD, Robicheau JT, Zemaitis MA. Reductive metabolism of the anticonvulsant agent zonisamide, a 1,2-benzisoxazole derivative. Xenobiotica. 1992;22:1–11.
Kitamura S, Sugihara K, Kuwasako M, Tatsumi K. The role of mammalian intestinal bacteria in the reductive metabolism of zonisamide. J Pharm Pharmacol. 1997;49:253–6.
Chan TS, Scaringella Y-S, Raymond K, Taub ME. Evaluation of erythromycin as a tool to assess CYP3A contribution of low clearance compounds in a long-term hepatocyte culture. Drug Metab Dispos. 2020;48:690–7.
Desch M, Wunderlich G, Goettel M, Goetz S, Liesenfeld K-H, Chan TS, et al. Effects of cytochrome P450 3A4 induction and inhibition on the pharmacokinetics of BI 425809, a novel glycine transporter 1 inhibitor. Eur J Drug Metab Pharmacokinet. 2022;47:1–13.
Ragia G, Dahl M-L, Manolopoulos V. Influence of CYP3A5 polymorphism on the pharmacokinetics of psychiatric drugs. Curr Drug Metab. 2016;17:227–36.
Daly AK. Significance of the minor cytochrome P450 3A isoforms. Clin Pharmacokinet. 2006;45:13–31.
Rosemond MJC, John-Williams LST, Yamaguchi T, Fujishita T, Walsh JS. Enzymology of a carbonyl reduction clearance pathway for the HIV integrase inhibitor, S-1360: role of human liver cytosolic aldo-keto reductases. Chem-biol Interact. 2004;147:129–39.
Ramsden D, Smith D, Arenas R, Frederick K, Cerny MA. Identification and characterization of a selective human carbonyl reductase 1 substrate. Drug Metab Dispos. 2018;46:1434–40.
Wermuth B. Purification and properties of an NADPH-dependent carbonyl reductase from human brain. Relationship to prostaglandin 9-ketoreductase and xenobiotic ketone reductase. J Biol Chem. 1981;256:1206–13.
Zientek MA, Youdim K. Reaction phenotyping: advances in the experimental strategies used to characterize the contribution of drug-metabolizing enzymes. Drug Metab Dispos. 2015;43:163–81.
Vidal LS, Kelly CL, Mordaka PM, Heap JT. Review of NAD(P)H-dependent oxidoreductases: Properties, engineering and application. Biochimica Et Biophysica Acta - Proteins Proteom. 2018;1866:327–47.
Malatkova P, Maser E, Wsol V. Human carbonyl reductases. Curr Drug Metab. 2010;11:639–58.
Di L, Balesano A, Jordan S, Shi SM. The role of alcohol dehydrogenase in drug metabolism: beyond ethanol oxidation. AAPS J. 2021;23:20.
Maser E. Xenobiotic carbonyl reduction and physiological steroid oxidoreduction. The pluripotency of several hydroxysteroid dehydrogenases. Biochem Pharmacol. 1995;49:421–40.
Yang X, Johnson N, Di L. Evaluation of cytochrome P450 selectivity for hydralazine as an aldehyde oxidase inhibitor for reaction phenotyping. J Pharm Sci. 2019;108:1627–30.
Sahi J, Khan K, Black C. Aldehyde oxidase activity and inhibition in hepatocytes and cytosolic fraction from mouse, rat, monkey and human. Drug Metab Lett. 2008;2:176–83.
Jan Y-H, Richardson JR, Baker AA, Mishin V, Heck DE, Laskin DL, et al. Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication. Toxicol Appl Pharm. 2015;288:114–20.
Li B, Sedlacek M, Manoharan I, Boopathy R, Duysen EG, Masson P, et al. Butyrylcholinesterase, paraoxonase, and albumin esterase, but not carboxylesterase, are present in human plasma. Biochem Pharmacol. 2005;70:1673–84.
ICH guideline M3(R2) on non-clinical safety studies for the conduct of human clinical trials and marketing authorisation for pharmaceuticals. https://www.ema.europa.eu/en/ich-m3-r2-non-clinical-safety-studies-conduct-human-clinical-trials-pharmaceuticals-scientific.
Schadt S, Bister B, Chowdhury SK, Funk C, Hop CECA, Humphreys WG, et al. A decade in the MIST: learnings from investigations of drug metabolites in drug development under the “Metabolites in Safety Testing” regulatory guidances. Drug Metab Dispos. 2018;46:865–78.
Acknowledgements
The authors would like to thank Dr. Timothy Tracy for reviewing the manuscript and providing scientific input.
Author information
Authors and Affiliations
Contributions
All authors approved of the final work that is published and agreed to be accountable for all aspects of the work with respect to accuracy and integrity. In addition, individual author contributions are listed below.
Tom S. Chan: Research design, conducted experiments, performed data analysis, contributed to writing manuscript.
Alexander Byer-Alcorace: Conducted experiments, performed data analysis.
Bachir Latli: Created reagents and analytical tools.
Pingrong Liu: Research design, conducted experiments, performed data analysis, contributed to writing manuscript.
Hlaing H. Maw: Conducted experiments, performed data analysis.
Klairynne G. Raymond: Research design, conducted experiments, performed data analysis.
Young-Sun Scaringella: Conducted experiments, performed data analysis.
Aaron Teitelbaum: Research design, performed data analysis, contributed to writing manuscript.
Ting Wang: Research design, performed data analysis.
Andrea Whitcher-Johnstone: Research design, conducted experiments, performed data analysis.
Mitchell E. Taub: Research design, contributed to writing manuscript.
Corresponding author
Ethics declarations
Conflict of Interest
TC, ABA, BL, PL, HM, KR, YS, AT, TW, and MT are full-time employees of Boehringer Ingelheim. AWJ was an employee of Boehringer Ingelheim at the time of this study.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary Information
Below is the link to the electronic supplementary material.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Chan, T.S., Byer-Alcorace, A.J., Latli, B. et al. Characterization of Divergent Metabolic Pathways in Elucidating an Unexpected, Slow-Forming, and Long Half-Life Major Metabolite of Iclepertin. Pharm Res 40, 1901–1913 (2023). https://doi.org/10.1007/s11095-023-03530-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11095-023-03530-z