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Kenny JR, Ramsden D, Buckley DB, Dallas S, Fung C, Mohutsky M, Einolf HJ, Chen L, Dekeyser JG, Fitzgerald M, Goosen TC, Siu YA, Walsky RL, Zhang G, Tweedie D, Hariparsad N. Considerations from the Innovation and Quality Induction Working Group in Response to Drug-Drug Interaction Guidances from Regulatory Agencies: Focus on CYP3A4 mRNA In Vitro Response Thresholds, Variability, and Clinical Relevance. Drug Metab Dispos 2018; 46:1285-1303. [PMID: 29959133 DOI: 10.1124/dmd.118.081927] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/18/2018] [Indexed: 01/08/2023] Open
Abstract
The Innovation and Quality Induction Working Group presents an assessment of best practice for data interpretation of in vitro induction, specifically, response thresholds, variability, application of controls, and translation to clinical risk assessment with focus on CYP3A4 mRNA. Single concentration control data and Emax/EC50 data for prototypical CYP3A4 inducers were compiled from many human hepatocyte donors in different laboratories. Clinical CYP3A induction and in vitro data were gathered for 51 compounds, 16 of which were proprietary. A large degree of variability was observed in both the clinical and in vitro induction responses; however, analysis confirmed in vitro data are able to predict clinical induction risk. Following extensive examination of this large data set, the following recommendations are proposed. a) Cytochrome P450 induction should continue to be evaluated in three separate human donors in vitro. b) In light of empirically divergent responses in rifampicin control and most test inducers, normalization of data to percent positive control appears to be of limited benefit. c) With concentration dependence, 2-fold induction is an acceptable threshold for positive identification of in vitro CYP3A4 mRNA induction. d) To reduce the risk of false positives, in the absence of a concentration-dependent response, induction ≥ 2-fold should be observed in more than one donor to classify a compound as an in vitro inducer. e) If qualifying a compound as negative for CYP3A4 mRNA induction, the magnitude of maximal rifampicin response in that donor should be ≥ 10-fold. f) Inclusion of a negative control adds no value beyond that of the vehicle control.
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Affiliation(s)
- Jane R Kenny
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Diane Ramsden
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - David B Buckley
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Shannon Dallas
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Conrad Fung
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Michael Mohutsky
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Heidi J Einolf
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Liangfu Chen
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Joshua G Dekeyser
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Maria Fitzgerald
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Theunis C Goosen
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Y Amy Siu
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Robert L Walsky
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - George Zhang
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Donald Tweedie
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
| | - Niresh Hariparsad
- Genentech, South San Francisco, California (J.R.K.); Boehringer Ingelheim, Ridgefield, Connecticut (D.R.); Sekisui-XenoTech LLC, Kansas City, Kansas (D.B.B.); Janssen R&D, Spring House, Pennsylvania (S.D.); Vertex Pharmaceuticals, Boston, Massachusetts (C.F., N.H.); Eli Lilly and Company, Indianapolis, Indiana (M.M.); Novartis, East Hanover, New Jersey (H.J.E.); GlaxoSmithKline, King of Prussia, Pennsylvania (L.C.); Amgen Inc., Cambridge, Massachusetts (J.G.D.); Sanofi, Waltham, Massachusetts (M.F.); Pfizer Global Research and Development, Groton, Connecticut (T.C.G.); Eisai, Andover, Massachusetts (Y.A.S.); EMD Serono R&D Institute, Inc., Billerica, Massachusetts (R.L.W.); Corning Life Sciences, Woburn, Massachusetts (G.Z.); and Merck & Co., Inc., Kenilworth, New Jersey (D.T.)
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Kazmi F, Yerino P, McCoy C, Parkinson A, Buckley DB, Ogilvie BW. An Assessment of the In Vitro Inhibition of Cytochrome P450 Enzymes, UDP-Glucuronosyltransferases, and Transporters by Phosphodiester- or Phosphorothioate-Linked Oligonucleotides. Drug Metab Dispos 2018; 46:1066-1074. [PMID: 29735754 DOI: 10.1124/dmd.118.081729] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/04/2018] [Indexed: 12/16/2022] Open
Abstract
Oligonucleotides represent an expanding class of pharmacotherapeutics in development for various indications. Typically, oligonucleotides are developed with phosphorothioate linkages for the improvement of biologic stability; however, limited data are available on the potential of these molecules to cause drug-drug interactions (DDIs). In this study, four nontherapeutic oligonucleotides with either a phosphodiester or phosphorothioate linkage and partial sequences towards glutathione peroxidase or β-actin (PD-GP and PD-Ac or PT-GP and PT-Ac, respectively) were evaluated in vitro for their potential to inhibit cytochrome P450 (P450) enzymes and UGP-glucuronosyltransferases (UGTs) in both human liver microsomes (HLMs) and cryopreserved human hepatocytes (CHHs) and to inhibit select transporters in expression systems. PD-GP and PD-Ac had little to no inhibitory effect on any P450 or UGT enzymes in HLMs and CHHs, except for PD-Ac in HLMs for CYP2C19 (IC50 = 29 μM). Conversely, PT-GP and PT-Ac caused direct inhibition of almost all P450 and UGT enzymes, with CYP1A2 (IC50 values of 0.8-4.2 μM), CYP2C8 (IC50 values of 1.1-12 μM), and UGT1A1 (IC50 values of 4.5-5.4 μM) inhibited to the greatest extent. There was evidence of possible time-dependent inhibition (TDI) of P450 enzymes with PT-GP and PT-Ac for CYP2B6, CYP2C8, CYP2C19, CYP2C9, CYP2D6, and CYP3A4/5; however, this TDI was reversible. In contrast to HLMs, there was little to no direct P450 inhibition by any oligonucleotide in CHHs [except for PD-Ac with CYP2C19 (IC50 = 36 μM) and TDI by PT-GP with CYP2C8], demonstrating test system-dependent outcomes. Inhibition was observed for the organic anion uptake transporters, including organic anion-transporting polypeptide OATP1B1 and OATP1B3, organic anion transporters OAT1 and OAT3, and organic cation transporter OCT2 (IC50 values of 12-29 μM), but not OCT1 or the efflux transporters breast cancer resistance protein and P-glycoprotein by the phosphorothioate oligonucleotides.
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Affiliation(s)
- Faraz Kazmi
- Sekisui XenoTech LLC, Kansas City, Kansas (F.K., P.Y., C.M., D.B.B., B.W.O.); Janssen Research & Development LLC, Spring House, Pennsylvania (F.K.); XPD Consulting, Shawnee, Kansas (A.P.); and Roivant Sciences, Durham, North Carolina (D.B.B.)
| | - Phyllis Yerino
- Sekisui XenoTech LLC, Kansas City, Kansas (F.K., P.Y., C.M., D.B.B., B.W.O.); Janssen Research & Development LLC, Spring House, Pennsylvania (F.K.); XPD Consulting, Shawnee, Kansas (A.P.); and Roivant Sciences, Durham, North Carolina (D.B.B.)
| | - Chase McCoy
- Sekisui XenoTech LLC, Kansas City, Kansas (F.K., P.Y., C.M., D.B.B., B.W.O.); Janssen Research & Development LLC, Spring House, Pennsylvania (F.K.); XPD Consulting, Shawnee, Kansas (A.P.); and Roivant Sciences, Durham, North Carolina (D.B.B.)
| | - Andrew Parkinson
- Sekisui XenoTech LLC, Kansas City, Kansas (F.K., P.Y., C.M., D.B.B., B.W.O.); Janssen Research & Development LLC, Spring House, Pennsylvania (F.K.); XPD Consulting, Shawnee, Kansas (A.P.); and Roivant Sciences, Durham, North Carolina (D.B.B.)
| | - David B Buckley
- Sekisui XenoTech LLC, Kansas City, Kansas (F.K., P.Y., C.M., D.B.B., B.W.O.); Janssen Research & Development LLC, Spring House, Pennsylvania (F.K.); XPD Consulting, Shawnee, Kansas (A.P.); and Roivant Sciences, Durham, North Carolina (D.B.B.)
| | - Brian W Ogilvie
- Sekisui XenoTech LLC, Kansas City, Kansas (F.K., P.Y., C.M., D.B.B., B.W.O.); Janssen Research & Development LLC, Spring House, Pennsylvania (F.K.); XPD Consulting, Shawnee, Kansas (A.P.); and Roivant Sciences, Durham, North Carolina (D.B.B.)
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Haupt LJ, Kazmi F, Ogilvie BW, Buckley DB, Smith BD, Leatherman S, Paris B, Parkinson O, Parkinson A. The Reliability of Estimating Ki Values for Direct, Reversible Inhibition of Cytochrome P450 Enzymes from Corresponding IC50 Values: A Retrospective Analysis of 343 Experiments. Drug Metab Dispos 2015; 43:1744-50. [PMID: 26354951 DOI: 10.1124/dmd.115.066597] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/08/2015] [Indexed: 11/22/2022] Open
Abstract
In the present study, we conducted a retrospective analysis of 343 in vitro experiments to ascertain whether observed (experimentally determined) values of Ki for reversible cytochrome P450 (P450) inhibition could be reliably predicted by dividing the corresponding IC₅₀ values by two, based on the relationship (for competitive inhibition) in which Ki = IC₅₀/2 when [S] (substrate concentration) = Km (Michaelis-Menten constant). Values of Ki and IC₅₀ were determined under the following conditions: 1) the concentration of P450 marker substrate, [S], was equal to Km (for IC₅₀ determinations) and spanned Km (for Ki determinations); 2) the substrate incubation time was short (5 minutes) to minimize metabolism-dependent inhibition and inhibitor depletion; and 3) the concentration of human liver microsomes was low (0.1 mg/ml or less) to maximize the unbound fraction of inhibitor. Under these conditions, predicted Ki values, based on IC₅₀/2, correlated strongly with experimentally observed Ki determinations [r = 0.940; average fold error (AFE) = 1.10]. Of the 343 predicted Ki values, 316 (92%) were within a factor of 2 of the experimentally determined Ki values, and only one value fell outside a 3-fold range. In the case of noncompetitive inhibitors, Ki values predicted from IC₅₀/2 values were overestimated by a factor of nearly 2 (AFE = 1.85; n = 13), which is to be expected because, for noncompetitive inhibition, Ki = IC₅₀ (not IC₅₀/2). The results suggest that, under appropriate experimental conditions with the substrate concentration equal to Km, values of Ki for direct, reversible inhibition can be reliably estimated from values of IC₅₀/2.
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Affiliation(s)
- Lois J Haupt
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Faraz Kazmi
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Brian W Ogilvie
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - David B Buckley
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Brian D Smith
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Sarah Leatherman
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Brandy Paris
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Oliver Parkinson
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
| | - Andrew Parkinson
- XenoTech, LLC, Lenexa, Kansas (L.J.H., F.K., B.W.O., D.B.B., B.D.S., S.L.); and XPD Consulting, Shawnee, Kansas (B.P., O.P., A.P.)
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