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Weston DJ, Thomas S, Boyle GW, Pieren M. Alpibectir: Early Qualitative and Quantitative Metabolic Profiling from a First-Time-in-Human Study by Combining 19F-NMR (Nuclear Magnetic Resonance), 1H-NMR, and High-Resolution Mass Spectrometric Analyses. Drug Metab Dispos 2024; 52:858-874. [PMID: 38769017 DOI: 10.1124/dmd.124.001562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/22/2024] Open
Abstract
Alpibectir (also known as BVL-GSK098 and GSK3729098) is a new chemical entity (NCE) with a novel mechanism for the treatment of tuberculosis. The disposition of alpibectir was determined in subjects from a first-time-in-human trial after a single oral dose of 40 mg and after 7 days repeat dosing at 30 mg. Here we present a combined approach of 19F-NMR (nuclear magnetic resonance), 1H-NMR, and high-resolution mass spectrometry (HRMS) to confidently determine the human metabolic fate of alpibectir. Utilizing multiple sites of fluorination in the molecule, it was possible to fractionate human urine and plasma to confidently detect and quantify the metabolite responses using 19F-NMR. Qualitative detection and structural characterization of F-containing NMR fractions were performed using complementary high-resolution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analyses to further add confidence to the metabolite responses in these fractions. Subsequent 1H-NMR then provided unequivocal standard-free structural confirmation for key metabolites, which would not be possible with conventional radioactivity detection and LC-MS/MS techniques. Alpibectir was shown to undergo extensive hydrolysis of the central amide moiety, where the resultant N-dealkylated amine and trifluorobutyric acid products were detected initially by unbiased 19F-NMR detection along with major downstream biotransformations to form a carbamoyl glucuronide conjugate and trifluoroacetic acid, respectively. Parallel UHPLC-MS/MS analyses provided confirmatory or additional structural characterization only where relevant. These concerted data allowed for the qualitative metabolic profile and quantitative determination of drug-related material (DRM) in urine and plasma, along with the percentage of dose excreted in urine, to be reported in a comprehensive, efficient, and data-led manner. SIGNIFICANCE STATEMENT: Combining the selectivity of 19F-NMR (nuclear magnetic resonance) for unfractionated samples as first-intent, data-led sample fractionation prior to 19F-NMR and structure-rich 1H-NMR detection, along with the sensitivity of high-resolution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), a novel alternative for time-efficient detection and quantification of drug-related material (DRM) in human without use of radiolabeled drug is reported. This allowed more complete data rationalization of human metabolism, permitting early risk assessment and progression of the development of antitubercular agent, alpibectir.
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Affiliation(s)
- Daniel J Weston
- Disposition and Biotransformation (D.J.W., S.T.) and DMPK Projects Group (G.W.B.), GSK, Stevenage, United Kingdom; and BioVersys AG, Basel, Switzerland (M.P.)
| | - Steve Thomas
- Disposition and Biotransformation (D.J.W., S.T.) and DMPK Projects Group (G.W.B.), GSK, Stevenage, United Kingdom; and BioVersys AG, Basel, Switzerland (M.P.)
| | - Gary W Boyle
- Disposition and Biotransformation (D.J.W., S.T.) and DMPK Projects Group (G.W.B.), GSK, Stevenage, United Kingdom; and BioVersys AG, Basel, Switzerland (M.P.)
| | - Michel Pieren
- Disposition and Biotransformation (D.J.W., S.T.) and DMPK Projects Group (G.W.B.), GSK, Stevenage, United Kingdom; and BioVersys AG, Basel, Switzerland (M.P.)
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Young GC, Spracklin DK, James AD, Hvenegaard MG, Scarfe G, Wagner DS, Georgi K, Schieferstein H, Bjornsdottir I, van Groen B, Romeo AA, Cassidy KC, Da-Violante G, Bister B, Blech S, Lyer R, Schulz SI, Cuyckens F, Moliner P. Considerations for Human ADME Strategy and Design Paradigm Shift(s) - An Industry White Paper. Clin Pharmacol Ther 2023; 113:775-781. [PMID: 35733280 DOI: 10.1002/cpt.2691] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/15/2022] [Indexed: 11/10/2022]
Abstract
The human absorption, distribution, metabolism, and excretion (hADME) study is the cornerstone of the clinical pharmacology package for small molecule drugs, providing comprehensive information on the rates and routes of disposition and elimination of drug-related material in humans through the use of 14 C-labeled drug. Significant changes have already been made in the design of the hADME study for many companies, but opportunity exists to continue to re-think both the design and timing of the hADME study in light of the potential offered by newer technologies, that enable flexibility in particular to reducing the magnitude of the radioactive dose used. This paper provides considerations on the variety of current strategies that exist across a number of pharmaceutical companies and on some of the ongoing debates around a potential move to the so called "human first/human only" approach, already adopted by at least one company. The paper also provides a framework for continuing the discussion in the application of further shifts in the paradigm.
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Affiliation(s)
- Graeme C Young
- GlaxoSmithKline Research & Development Ltd., David Jack Centre, Ware, UK
| | | | | | | | - Graeme Scarfe
- AstraZeneca, Cambridge Biomedical Campus, Cambridge, UK
| | | | - Katrin Georgi
- The Healthcare Business of Merck KGaA, Darmstadt, Germany
| | | | | | | | - Andrea A Romeo
- Roche Pharma Research and Early Development, Basel, Switzerland
| | | | | | - Bojan Bister
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Stefan Blech
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
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Khojasteh SC, Argikar UA, Driscoll JP, Heck CJS, King L, Jackson KD, Jian W, Kalgutkar AS, Miller GP, Kramlinger V, Rietjens IMCM, Teitelbaum AM, Wang K, Wei C. Novel advances in biotransformation and bioactivation research - 2020 year in review. Drug Metab Rev 2021; 53:384-433. [PMID: 33910427 PMCID: PMC8826528 DOI: 10.1080/03602532.2021.1916028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This annual review is the sixth of its kind since 2016 (see references). Our objective is to explore and share articles which we deem influential and significant in the field of biotransformation and bioactivation. These fields are constantly evolving with new molecular structures and discoveries of corresponding pathways for metabolism that impact relevant drug development with respect to efficacy and safety. Based on the selected articles, we created three sections: (1) drug design, (2) metabolites and drug metabolizing enzymes, and (3) bioactivation and safety (Table 1). Unlike in years past, more biotransformation experts have joined and contributed to this effort while striving to maintain a balance of authors from academic and industry settings.
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Affiliation(s)
- S Cyrus Khojasteh
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., South San Francisco, CA, USA
| | - Upendra A Argikar
- Translational Medicine, Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | - James P Driscoll
- Department of Drug Metabolism and Pharmacokinetics, MyoKardia, Inc., South San Francisco, CA, USA
| | - Carley J S Heck
- Medicine Design, Pfizer Worldwide Research, Development and Medical, Groton, CT, USA
| | - Lloyd King
- Department of DMPK, UCB Biopharma, Slough, UK
| | - Klarissa D Jackson
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, Chapel Hill, NC, USA
| | - Wenying Jian
- Drug Metabolism and Pharmacokinetics, Janssen Research & Development, Spring House, PA, USA
| | - Amit S Kalgutkar
- Medicine Design, Pfizer Worldwide Research, Development and Medical, Cambridge, MA, USA
| | - Grover P Miller
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Valerie Kramlinger
- Translational Medicine, Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | | | - Aaron M Teitelbaum
- Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA
| | - Kai Wang
- Drug Metabolism and Pharmacokinetics, Janssen Research & Development, San Diego, CA, USA
| | - Cong Wei
- Drug Metabolism & Pharmacokinetics, Biogen Inc., Cambridge, MA, USA
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Roffel A, Lier JJV, Rozema G, van Hoogdalem EJ. Predictability of Elimination and Excretion of Small Molecules from Animals to Humans, and Impact on Dosimetry for human ADME Studies with Radiolabeled Drugs. Curr Rev Clin Exp Pharmacol 2021; 17:26-38. [PMID: 33687900 DOI: 10.2174/1574884716666210309103625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND We assessed the extent to which urinary and fecal excretion of 14C-labeled drug material in animal ADME studies was predictive of human ADME studies. We compared observed plasma elimination half lives for total drug related radioactivity in humans to pre-study predictions, and we estimated the impact of any major differences on human dosimetry calculations. METHODS We included 34 human ADME studies with doses of 14C above 0.1 MBq. We calculated ratios of dosimetry input parameters (percentage fecal excretion in humans versus animals; observed half life in humans versus predicted pre-study) and output parameters (effective dose post-study versus pre study) and assessed their relationship. RESULTS A quantitative correlation assessment did not show a statistically significant correlation between the ratios of percentages of 14C excreted in feces and the ratios of dosimetry outcomes in the entire dataset, but a statistically significant correlation was found when assessing the studies that were based on ICRP 60/62 (n=19 studies; P=0.0028). There also appeared to be a correlation between the plasma half-life ratios and the ratios of dosimetry results. A quantitative correlation assessment showed that there was a statistically significant correlation between these ratios (P<0.0001). CONCLUSION In all cases where the plasma elimination half-life for 14C in humans was found to be longer than the predicted value, the radiation burden was still within ICRP Category IIa. Containment of the actual radiation burden below the limit of 1.00 mSv appeared to be determined partly also by our choice to limit 14C doses to 3.7 MBq.
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Affiliation(s)
- Ad Roffel
- Department of Scientific Affairs, Clinical Pharmacology. Netherlands
| | | | - Gerk Rozema
- Department of Data Support, PRA Health Sciences, Groningen. Netherlands
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Kim A, Dueker SR, Hwang JG, Yoon J, Lee SW, Lee HS, Yu BY, Yu KS, Lee H. An Investigation of the Metabolism and Excretion of KD101 and Its Interindividual Differences: A Microtracing Mass Balance Study in Humans. Clin Transl Sci 2021; 14:231-238. [PMID: 33460293 PMCID: PMC7877834 DOI: 10.1111/cts.12848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/24/2020] [Indexed: 11/28/2022] Open
Abstract
The absorption, metabolism, and excretion (AME) profiles of KD101, currently under clinical development to treat obesity, were assessed in humans using accelerator mass spectrometry (AMS) after a single oral administration of KD101 at 400 mg and a microdose of 14C‐KD101 at ~ 35.2 μg with a total radioactivity of 6.81 kBq. The mean total recovery of administered radioactivity was 85.2% with predominant excretion in the urine (78.0%). The radio‐chromatographic metabolite profiling showed that most of the total radioactivity in the plasma and the urine was ascribable to metabolites. The UDP‐glucuronosyltransferase (UGT), including UGT1A1, UGT1A3, and UGT2B7, might have contributed to the interindividual variability in the metabolism and excretion of KD101. The microtracing approach using AMS is a useful tool to evaluate the AME of a drug under development without risk for high radiation exposure to humans.
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Affiliation(s)
- Anhye Kim
- Department of Clinical Pharmacology and Therapeutics, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Stephen R Dueker
- BioCore Co., Ltd., Seoul, Korea.,Korean Institute of Radiological and Medical Science, Seoul, Korea
| | - Jun Gi Hwang
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea.,Department of Clinical Pharmacology and Therapeutics, Chung Buk National University Hospital, College of Medicine, Cheongju-si, Chungcheongbuk-do, Korea
| | - Jangsoo Yoon
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea
| | - Sang-Won Lee
- Clinical Trial Center, Hanyang University Seoul Hospital, Seoul, Korea
| | - Hye Suk Lee
- Drug Metabolism and Bioanalysis Laboratory, College of Pharmacy, The Catholic University of Korea, Bucheon, Korea
| | - Byung-Yong Yu
- Korea Institute of Science and Technology, Seoul, Korea
| | - Kyung-Sang Yu
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea
| | - Howard Lee
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
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Takahashi RH, Chang JH, Pang J, Liang X, Ma S. Unequal Absorption of Radiolabeled and Nonradiolabeled Drug from the Oral Dose Leads to Incorrect Estimates of Drug Absorption and Circulating Metabolites in a Mass Balance Study. Drug Metab Lett 2018; 13:37-44. [PMID: 30499424 DOI: 10.2174/1872312813666181129162237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/21/2018] [Accepted: 11/27/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Mass balance studies conducted using radiolabeled material (14C or 3H) definitively characterize the Absorption, Metabolism, and Excretion (AME) of a drug. A critical aspect of these studies is that the radiotracer maintains its proportion to total drug from its administration to its complete elimination from the body. In the study of GDC-0276 in beagle dogs, we observed that the 14C radiotracer proportion (specific activity) varied through the study. METHOD High resolution-accurate mass spectrometric measurements of 12C and 14C isotopes of GDC- 0276 and its metabolites in plasma and excreta samples were used to determine the apparent specific activities, which were higher than the specific activity of the dosing formulation. Drug concentrations were adjusted to the observed specific activities to correct the readouts for GDC-0276 AME and PK. RESULTS The enrichment of 14C, which resulted in higher specific activities, was consistent with faster and more extensive absorption of the radiotracer from the dosing formulation. This resulted in overestimating the dose absorbed, the extent of elimination in urine and bile, and the exposures to circulating metabolites. These biases were corrected by the specific activities determined for study samples by mass spectrometry. CONCLUSION Assuming that the radiotracer was proportional to total drug throughout a radiolabeled study was not valid in a 14C study in beagle dogs. This presumably resulted from unequal absorption of the radiotracer and nonradiolabeled test articles from the oral dose due to inequivalent solid forms. We were able to provide a more accurate description of the AME of GDC-0276 in dogs by characterizing the differential absorption of the radiotracer.
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Affiliation(s)
- Ryan H Takahashi
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, United States
| | - Jae H Chang
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, United States
| | - Jodie Pang
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, United States
| | - Xiaorong Liang
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, United States
| | - Shuguang Ma
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, United States
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Evaluation of cAMS for 14C microtracer ADME studies: opportunities to change the current drug development paradigm. Bioanalysis 2018; 10:321-339. [DOI: 10.4155/bio-2017-0216] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aim: Although regulatory guidances require human metabolism information of drug candidates early in the development process, the human mass balance study (or hADME study), is performed relatively late. hADME studies typically involve the administration of a 14C-radiolabelled drug where biological samples are measured by conventional scintillation counting analysis. Another approach is the administration of therapeutic doses containing a 14C-microtracer followed by accelerator mass spectrometry (AMS) analysis, enabling hADME studies completion much earlier. Consequently, there is an opportunity to change the current drug development paradigm. Materials & methods: To evaluate the applicability of the MICADAS–cAMS method, we successfully performed: the validation of MICADAS–cAMS for radioactivity quantification in biomatrices and, a rat ADME study, where the conventional methodology was assessed against a microtracer MICADAS–cAMS approach. Results & discussion: Combustion AMS (cAMS) technology is applicable to microtracer studies. A favorable opinion from EMA to complete the hADME in a Phase I setting was received, opening the possibilities to change drug development.
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James AD, Marvalin C, Luneau A, Meissner A, Camenisch G. Comparison of 19F NMR and 14C Measurements for the Assessment of ADME of BYL719 (Alpelisib) in Humans. Drug Metab Dispos 2017; 45:900-907. [DOI: 10.1124/dmd.117.075424] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/22/2017] [Indexed: 01/15/2023] Open
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Hatsis P, Waters NJ, Argikar UA. Implications for Metabolite Quantification by Mass Spectrometry in the Absence of Authentic Standards. Drug Metab Dispos 2017; 45:492-496. [PMID: 28254953 DOI: 10.1124/dmd.117.075259] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/01/2017] [Indexed: 01/15/2023] Open
Abstract
Quantification of metabolites by mass spectrometry in the absence of authentic reference standards or without a radiolabel is often called "semiquantitative," which acknowledges that mass spectrometric responses are not truly quantitative. For many researchers, it is tempting to pursue this practice of semiquantification in early drug discovery and even preclinical development, when radiolabeled absorption, distribution, metabolism, and excretion studies are being deferred to later stages of drug development. The caveats of quantifying metabolites based on parent drug response are explored in this investigation. A set of 71 clinically relevant drugs/metabolites encompassing common biotransformation pathways was subjected to flow injection analysis coupled with electrospray ionization (ESI) mass spectrometry. The results revealed a large variation in ESI response even for structurally similar parent drug/metabolite pairs. The ESI response of each metabolite was normalized to that of the parent drug to generate an ESI relative response factor. Overall, relative response factors ranged from 0.014 (>70-fold lower response than parent) to 8.6 (8.6-fold higher response than parent). Various two-dimensional molecular descriptors were calculated that describe physicochemical, topological, and structural properties for each drug/metabolite. The molecular descriptors, along with the ESI response factors, were used in univariate analyses as well as a principal components analysis to ascertain which molecular descriptors best account for the observed discrepancies in drug/metabolite ESI response. This investigation has shown that the practice of using parent drug response to quantify metabolites should be used with caution.
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Affiliation(s)
- Panos Hatsis
- Drug Metabolism & Pharmacokinetics, Novartis Institutes for Biomedical Research Inc., East Hanover, New Jersey (P.H); Syros Pharmaceuticals, Cambridge, Massachusetts (N.J.W); and Analytical Sciences & Imaging, Novartis Institutes for Biomedical Research Inc., Cambridge, Massachusetts (U.A.A)
| | - Nigel J Waters
- Drug Metabolism & Pharmacokinetics, Novartis Institutes for Biomedical Research Inc., East Hanover, New Jersey (P.H); Syros Pharmaceuticals, Cambridge, Massachusetts (N.J.W); and Analytical Sciences & Imaging, Novartis Institutes for Biomedical Research Inc., Cambridge, Massachusetts (U.A.A)
| | - Upendra A Argikar
- Drug Metabolism & Pharmacokinetics, Novartis Institutes for Biomedical Research Inc., East Hanover, New Jersey (P.H); Syros Pharmaceuticals, Cambridge, Massachusetts (N.J.W); and Analytical Sciences & Imaging, Novartis Institutes for Biomedical Research Inc., Cambridge, Massachusetts (U.A.A)
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Srinivas NR. Interspecies scaling of excretory amounts using allometry - retrospective analysis with rifapentine, aztreonam, carumonam, pefloxacin, miloxacin, trovafloxacin, doripenem, imipenem, cefozopran, ceftazidime, linezolid for urinary excretion and rifapentine, cabotegravir, and dolutegravir for fecal excretion. Xenobiotica 2016; 46:784-92. [PMID: 26711252 DOI: 10.3109/00498254.2015.1121554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 11/11/2015] [Accepted: 11/15/2015] [Indexed: 11/13/2022]
Abstract
1. Interspecies allometry scaling for prediction of human excretory amounts in urine or feces was performed for numerous antibacterials. Antibacterials used for urinary scaling were: rifapentine, pefloxacin, trovafloxacin (Gr1/low; <10%); miloxacin, linezolid, PNU-142300 (Gr2/medium; 10-40%); aztreonam, carumonam, cefozopran, doripenem, imipenem, and ceftazidime (Gr3/high; >50%). Rifapentine, cabotegravir, and dolutegravir was used for fecal scaling (high; >50%). 2. The employment of allometry equation: Y = aW(b) enabled scaling of urine/fecal amounts from animal species. Corresponding predicted amounts were converted into % recovery by considering the respective human dose. Comparison of predicted/observed values enabled fold difference and error calculations (mean absolute error [MAE] and root mean square error [RMSE]). Comparisons were made for urinary/fecal data; and qualitative assessment was made amongst Gr1/Gr2/Gr3 for urine. 3. Average correlation coefficient for the allometry scaling was >0.995. Excretory amount predictions were largely within 0.75- to 1.5-fold differences. Average MAE and RMSE were within ±22% and 23%, respectively. Although robust predictions were achieved for higher urinary/fecal excretion (>50%), interspecies scaling was applicable for low/medium excretory drugs. 4. Based on the data, interspecies scaling of urine or fecal excretory amounts may be potentially used as a tool to understand the significance of either urinary or fecal routes of elimination in humans in early development.
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Affiliation(s)
- Nuggehally R Srinivas
- a Department of Integrated Drug Development , Suramus Bio , Bangalore , Karnataka , India
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The impact of early human data on clinical development: there is time to win. Drug Discov Today 2016; 21:873-9. [PMID: 27046542 DOI: 10.1016/j.drudis.2016.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/18/2016] [Accepted: 03/23/2016] [Indexed: 12/16/2022]
Abstract
Modern accelerator mass spectrometry (AMS) methods enable the routine application of this technology in drug development. By the administration of a (14)C-labelled microdose or microtrace, pharmacokinetic (PK) data, such as mass balance, metabolite profiling, and absolute bioavailability (AB) data, can be generated easier, faster, and at lower costs. Here, we emphasize the advances and impact of this technology for pharmaceutical companies. The availability of accurate intravenous (iv) PK and human absorption, distribution, metabolism, and excretion (ADME) information, even before or during Phase I trials, can improve the clinical development plan. Moreover, applying the microtrace approach during early clinical development might impact the number of clinical pharmacology and preclinical safety pharmacology studies required, and shorten the overall drug discovery program.
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Absolute quantification of imipramine and its metabolites in vivo utilizing calibrators from radiolabeled in vitro incubations. Bioanalysis 2016; 8:297-309. [PMID: 26847656 DOI: 10.4155/bio.15.259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND We have demonstrated the use of a single-point calibration approach, derived from in vitro metabolite identification studies utilizing radiolabeled imipramine, that allows for the quantitation of metabolites from in vivo studies in the absence of metabolite synthetic standards. RESULTS From the in vivo study of imipramine in rats, the concentration of parent and metabolites were determined using the single-point calibration approach. Sixty seven percent of the dosed imipramine was recovered within 24 h, with 95 and 5% of drug-related material detected in feces and urine, respectively. CONCLUSION Using a novel single-point calibration approach from radiolabeled in vitro studies, we quantified metabolites in vivo and determined various disposition pathways.
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14
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Radiolabeled metabolite and disposition studies in support of safety assessment. Bioanalysis 2015; 7:507-11. [DOI: 10.4155/bio.15.18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Comparison of minipig, dog, monkey and human drug metabolism and disposition. J Pharmacol Toxicol Methods 2014; 74:80-92. [PMID: 25545337 DOI: 10.1016/j.vascn.2014.12.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/02/2014] [Accepted: 12/16/2014] [Indexed: 02/06/2023]
Abstract
INTRODUCTION This article gives an overview of the drug metabolism and disposition (ADME) characteristics of the most common non-rodent species used in toxicity testing of drugs (minipigs, dogs, and monkeys) and compares these to human characteristics with regard to enzymes mediating the metabolism of drugs and the transport proteins which contribute to the absorption, distribution and excretion of drugs. METHODS Literature on ADME and regulatory guidelines of relevance in drug development of small molecules has been gathered. RESULTS Non-human primates (monkeys) are the species that is closest to humans in terms of genetic homology. Dogs have an advantage due to the ready availability of comprehensive background data for toxicological safety assessment and dogs are easy to handle. Pigs have been used less than dogs and monkeys as a model in safety assessment of drug candidates. However, when a drug candidate is metabolised by aldehyde oxidase (AOX1), N-acetyltransferases (NAT1 and NAT2) or cytochrome (CYP2C9-like) enzymes which are not expressed in dogs, but are present in pigs, this species may be a better choice than dogs, provided that adequate exposure can be obtained in pigs. Conversely, pigs might not be the right choice if sulfation, involving 3-phospho-adenosyl-5-phosphosulphate sulphotransferase (PAPS) is an important pathway in the human metabolism of a drug candidate. DISCUSSION In general, the species selection should be based on comparison between in vitro studies with human cell-based systems and animal-cell-based systems. Results from pharmacokinetic studies are also important for decision-making by establishing the obtainable exposure level in the species. Access to genetically humanized mouse models and highly sensitive analytical methods (accelerator mass spectrometry) makes it possible to improve the chance of finding all metabolites relevant for humans before clinical trials have been initiated and, if necessary, to include another animal species before long term toxicity studies are initiated. In conclusion, safety testing can be optimized by applying knowledge about species ADME differences and utilising advanced analytical techniques.
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Pellegatti M. The debate on animal ADME studies in drug development: an update. Expert Opin Drug Metab Toxicol 2014; 10:1615-20. [PMID: 25373428 DOI: 10.1517/17425255.2015.979152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The preparation and release of the International Conference on Harmonisation guideline on safety evaluation of human metabolites and the technical progresses in bioanalysis have triggered an intense debate on the value of absorption, distribution, metabolism and excretion radiolabelled studies in animals. Some authors have radically challenged the traditional approach whereas others, while accepting the need of significant changes, argue that these studies remain an irreplaceable component of the preclinical registration dossier. This paper reviews some of the representative positions and describes the potential evolution.
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Haglund J, Halldin MM, Brunnström Å, Eklund G, Kautiainen A, Sandholm A, Iverson SL. Pragmatic Approaches to Determine the Exposures of Drug Metabolites in Preclinical and Clinical Subjects in the MIST Evaluation of the Clinical Development Phase. Chem Res Toxicol 2014; 27:601-10. [DOI: 10.1021/tx400449z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Johanna Haglund
- AstraZeneca R&D, DMPK Södertälje, SE-151 85 Södertälje, Sweden
| | | | - Åsa Brunnström
- AstraZeneca R&D, DMPK Södertälje, SE-151 85 Södertälje, Sweden
| | - Göran Eklund
- AstraZeneca R&D, DMPK Södertälje, SE-151 85 Södertälje, Sweden
| | | | - Anna Sandholm
- AstraZeneca R&D, DMPK Södertälje, SE-151 85 Södertälje, Sweden
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18
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Identification of drug metabolites in human plasma or serum integrating metabolite prediction, LC-HRMS and untargeted data processing. Bioanalysis 2014; 5:2115-28. [PMID: 23962251 DOI: 10.4155/bio.13.178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Comprehensive identification of human drug metabolites in first-in-man studies is crucial to avoid delays in later stages of drug development. We developed an efficient workflow for systematic identification of human metabolites in plasma or serum that combines metabolite prediction, high-resolution accurate mass LC-MS and MS vendor independent data processing. Retrospective evaluation of predictions for 14 (14)C-ADME studies published in the period 2007-January 2012 indicates that on average 90% of the major metabolites in human plasma can be identified by searching for accurate masses of predicted metabolites. Furthermore, the workflow can identify unexpected metabolites in the same processing run, by differential analysis of samples of drug-dosed subjects and (placebo-dosed, pre-dose or otherwise blank) control samples. To demonstrate the utility of the workflow we applied it to identify tamoxifen metabolites in serum of a breast cancer patient treated with tamoxifen. RESULTS & CONCLUSION Previously published metabolites were confirmed in this study and additional metabolites were identified, two of which are discussed to illustrate the advantages of the workflow.
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A reflection on fit-for-purpose metabolite investigation at different stages of drug development. Bioanalysis 2014; 6:591-4. [DOI: 10.4155/bio.14.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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20
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Li Y, Zhou J, Ramsden D, Taub ME, O'Brien D, Xu J, Busacca CA, Gonnella N, Tweedie DJ. Enzyme-transporter interplay in the formation and clearance of abundant metabolites of faldaprevir found in excreta but not in circulation. Drug Metab Dispos 2013; 42:384-93. [PMID: 24346834 DOI: 10.1124/dmd.113.055863] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Faldaprevir is a hepatitis C virus protease inhibitor that effectively reduces viral load in patients. Since faldaprevir exhibits slow metabolism in vitro and low clearance in vivo, metabolism was expected to be a minor clearance pathway. The human [(14)C] absorption, distribution, metabolism, and excretion study revealed that two monohydroxylated metabolites (M2a and M2b) were the most abundant excretory metabolites in feces, constituting 41% of the total administered dose. To deconvolute the formation and disposition of M2a and M2b in humans and determine why the minor change in structure [the addition of 16 atomic mass units (amu)] produced chemical entities that were excreted and were not present in the circulation, multiple in vitro test systems were used. The results from these in vitro studies clarified the formation and clearance of M2a and M2b. Faldaprevir is metabolized primarily in the liver by CYP3A4/5 to form M2a and M2b, which are also substrates of efflux transporters (P-glycoprotein and breast cancer resistance protein). The role of transporters is considered important for M2a and M2b as they demonstrate low permeability. It is proposed that both metabolites are efficiently excreted via bile into feces and do not enter the systemic circulation to an appreciable extent. If these metabolites permeate to blood, they can be readily taken up into hepatocytes from the circulation by uptake transporters (likely organic anion transporting polypeptides). These results highlight the critical role of drug-metabolizing enzymes and multiple transporters in the process of the formation and clearance of faldaprevir metabolites. Faldaprevir metabolism also provides an interesting case study for metabolites that are exclusively excreted in feces but are of clinical relevance.
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Affiliation(s)
- Yongmei Li
- Drug Metabolism & Pharmacokinetics (Y.L., J.Z., D.R., M.E.T., D.O., J.X., D.J.T.), Chemical Development (C.A.B.), and Analytical Development (N.G.), Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
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21
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New bioanalytical technologies and concepts: worth the fuss? Bioanalysis 2013; 5:1969-73. [DOI: 10.4155/bio.13.151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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22
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Bloomer JC, Nash M, Webb A, Miller BE, Lazaar AL, Beaumont C, Guiney WJ. Assessment of potential drug interactions by characterization of human drug metabolism pathways using non-invasive bile sampling. Br J Clin Pharmacol 2013; 75:488-96. [PMID: 22670830 DOI: 10.1111/j.1365-2125.2012.04352.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 05/15/2012] [Indexed: 11/30/2022] Open
Abstract
AIM Characterization of the biliary disposition of GSK1325756, using a non-invasive bile sampling technique and spectrometric analyses, to inform the major routes of metabolic elimination and to enable an assessment of victim drug interaction risk. METHOD Sixteen healthy, elderly subjects underwent non-invasive bile capture using a peroral string device (Entero-Test(®)) prior to and following a single oral dose of GSK1325756 (100 mg). The device was swallowed by each subject and once the weighted string was judged to have reached the duodenum, gallbladder contraction was stimulated in order to release bile. The string was then retrieved via the mouth and bile samples were analyzed for drug-related material using spectrometric and spectroscopic techniques following solvent extraction. RESULTS Nuclear magnetic resonance spectroscopy (NMR) indicated that the O-glucuronide metabolite was the major metabolite of GSK1325756, representing approximately 80% of drug-related material in bile. As bile is the major clearance route for GSK1325756 (only 4% of the administered dose was excreted in human urine), this result indicates that uridine 5'-diphospho-glucuronosyltransferases (UGTs) are the major drug metabolizing enzymes responsible for drug clearance. The relatively minor contribution made by oxidative routes reduces the concern of CYP-mediated victim drug interactions. CONCLUSION The results from this study demonstrate the utility of deploying the Entero-Test® in early human studies to provide information on the biliary disposition of drugs and their metabolites. This technique can be readily applied in early clinical development studies to provide information on the risk of interactions for drugs that are metabolized and eliminated in bile.
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Atzrodt J, Derdau V. Selected scientific topics of the 11th International Isotope Symposium on the Synthesis and Applications of Isotopes and Isotopically Labeled Compounds. J Labelled Comp Radiopharm 2013; 56:408-16. [PMID: 24285513 DOI: 10.1002/jlcr.3096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/19/2013] [Accepted: 06/19/2013] [Indexed: 01/02/2023]
Abstract
This micro-review describes hot topics and new trends in isotope science discussed at the 11th International Isotope Symposium on the Synthesis and Applications of Isotopes and Isotopically Labeled Compounds from a personal perspective.
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Affiliation(s)
- Jens Atzrodt
- Isotope Chemistry & Metabolite Synthesis, DSAR-DD, Sanofi-Aventis Deutschland GmbH, Industriepark Höchst G876, 65926, Frankfurt am Main, Germany
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Pellegatti M. Dogs and monkeys in preclinical drug development: the challenge of reducing and replacing. Expert Opin Drug Metab Toxicol 2013; 9:1171-80. [PMID: 23705836 DOI: 10.1517/17425255.2013.804061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Animal experimentation is a very contentious issue affecting reputation of drug industry. There are several reasons to forecast an increase in the number of dogs and monkeys used in safety and pharmacokinetic studies. This increase may trigger a strong reaction of the public opinion. There have been many proposals and initiatives to change the present approach to safety and metabolic studies. Tests based on new technologies, in vitro cell assays, stem cells, imaging, and computational systems, have the potential to anticipate effects in humans. Unfortunately, all these efforts and ideas have not changed standard approaches and regulatory expectations. AREAS COVERED This review looks at opportunities to reduce the number of dogs and monkeys currently used in pharmaceutical research. It also discusses present efforts and approaches, their strengths and potentials and the reasons why they may not fulfill expectations. EXPERT OPINION Unless the pharmaceutical industry gets more involved, an alternative paradigm of preclinical drug development is unlikely to be established in the foreseeable future. One can imagine a scenario where the political pressure against the use of dogs and monkeys in biomedical research becomes irresistible while alternative methods are not yet established. To avoid this situation, the pharmaceutical industry should take the lead and preclinical scientists at all levels need to influence decision makers and help develop new innovative approaches in drug safety evaluation.
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Metabolite structure analysis by high-resolution MS: supporting drug-development studies. Bioanalysis 2013; 5:463-79. [DOI: 10.4155/bio.13.3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Effective characterization of drug metabolites in complex biological matrices is facilitated by mass spectrometers with high resolving power, mass accuracy and sensitivity. This review begins with an overview of high-resolution MS terminology and the different types of instrumentation that are currently available. Metabolite structure analysis offers unique challenges and, therefore, the different types of approaches used to solve problems are highlighted through specific examples. Overall, this review describes the value that high-resolution MS brings to drug-metabolism studies.
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Conference Report: A hitchhiker’s guide to outsourcing ADME studies: the inside of outsourcing. Bioanalysis 2013; 5:403-5. [DOI: 10.4155/bio.12.328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This report gives a summary of the key points raised during a roundtable discussion convened at the American Association of Pharmaceutical Scientists 2012 Annual Meeting and Exposition held in Chicago on 17 October 2012. The science of ADME continues to grow, as does the impact of these studies on drug development. Understanding ADME requires efforts from several scientific specialties. With reductions in pharmaceutical company R&D staff there has been a corresponding growth in CROs with the capabilities and expertise to perform ADME work. This roundtable explored the challenges inherent in understanding ADME and the issues that arise when ADME studies shift from in-house study directors to external scientists working within the business model of a CRO. Pharmaceutical industry scientists and procurement specialists can satisfy their expectations by awareness of the growing expertise within CROs and the need for open communication among all partners involved in outsourced work.
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Obach RS, Nedderman AN, Smith DA. A response to “radiolabelled mass-balance excretion and metabolism studies in laboratory animals: a commentary on why they are still necessary”. Xenobiotica 2012. [DOI: 10.3109/00498254.2012.708193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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White RE, Evans DC, Hop CECA, Moore DJ, Prakash C, Surapaneni S, Tse FLS. Radiolabeled mass-balance excretion and metabolism studies in laboratory animals: a commentary on why they are still necessary. Xenobiotica 2012; 43:219-25; discussion 226-7. [DOI: 10.3109/00498254.2012.706724] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Luffer-Atlas D. The early estimation of circulating drug metabolites in humans. Expert Opin Drug Metab Toxicol 2012; 8:985-97. [PMID: 22681256 DOI: 10.1517/17425255.2012.693159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION An evolution in bioanalytical methodologies to identify and quantify drug metabolites has led to a wealth of biotransformation information during preclinical and early clinical testing phases. However, this abundance of metabolism data has not clarified how to select the most important circulating human metabolites for safety assessment. Consequently, more stringent regulatory expectations for a comprehensive approach to human metabolism have led pharmaceutical sponsors to employ a variety of novel methods to estimate circulating drug metabolites in humans and animals. AREAS COVERED This review provides context for 'why' human circulating metabolites must be qualified for safety in animals. A detailed overview is also presented concerning 'where,' 'how' and 'when' to conduct these assessments during drug development. EXPERT OPINION A human metabolite qualification strategy is now a required element of the drug safety package submitted with a new drug application (NDA). The important question is whether or not this additional information, about metabolite safety, is making human drugs any safer. Currently, this is a debatable issue, especially because stand-alone metabolite testing is fraught with its own challenges. As drug development moves into the twenty-first century, there is a pressing need for more sophisticated methodologies to address human drug and metabolite safety.
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Affiliation(s)
- Debra Luffer-Atlas
- Department of Drug Disposition, Lilly Research Laboratories, Indianapolis, IN 46285, USA.
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HRMS: current usage, future directions and the promise of integration with unified data streams suited to post-acquisition mining. Bioanalysis 2012; 4:471-6. [DOI: 10.4155/bio.12.17] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Isin EM, Elmore CS, Nilsson GN, Thompson RA, Weidolf L. Use of Radiolabeled Compounds in Drug Metabolism and Pharmacokinetic Studies. Chem Res Toxicol 2012; 25:532-42. [DOI: 10.1021/tx2005212] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emre M. Isin
- CVGI iMed DMPK, ADME Section‡DMPK iMed, Screening & Profiling, Isotope Chemistry, and §DMPK iMed, Centre of Excellence, AstraZeneca R&D, Mölndal, SE 431 83 Sweden
| | - Charles S. Elmore
- CVGI iMed DMPK, ADME Section‡DMPK iMed, Screening & Profiling, Isotope Chemistry, and §DMPK iMed, Centre of Excellence, AstraZeneca R&D, Mölndal, SE 431 83 Sweden
| | - Göran N. Nilsson
- CVGI iMed DMPK, ADME Section‡DMPK iMed, Screening & Profiling, Isotope Chemistry, and §DMPK iMed, Centre of Excellence, AstraZeneca R&D, Mölndal, SE 431 83 Sweden
| | - Richard A. Thompson
- CVGI iMed DMPK, ADME Section‡DMPK iMed, Screening & Profiling, Isotope Chemistry, and §DMPK iMed, Centre of Excellence, AstraZeneca R&D, Mölndal, SE 431 83 Sweden
| | - Lars Weidolf
- CVGI iMed DMPK, ADME Section‡DMPK iMed, Screening & Profiling, Isotope Chemistry, and §DMPK iMed, Centre of Excellence, AstraZeneca R&D, Mölndal, SE 431 83 Sweden
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Penner N, Xu L, Prakash C. Radiolabeled Absorption, Distribution, Metabolism, and Excretion Studies in Drug Development: Why, When, and How? Chem Res Toxicol 2012; 25:513-31. [DOI: 10.1021/tx300050f] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Natalia Penner
- Department
of Drug Metabolism and Preclinical Safety, Biogen Idec, Cambridge, Massachusetts 02142
| | - Lin Xu
- Department
of Drug Metabolism and Preclinical Safety, Biogen Idec, Cambridge, Massachusetts 02142
| | - Chandra Prakash
- Department
of Drug Metabolism and Preclinical Safety, Biogen Idec, Cambridge, Massachusetts 02142
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Guengerich FP. Introduction: use of radioactive compounds in drug discovery and development. Chem Res Toxicol 2012; 25:511-2. [PMID: 22324508 DOI: 10.1021/tx3000522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pellegatti M. Preclinical in vivo ADME studies in drug development: a critical review. Expert Opin Drug Metab Toxicol 2012; 8:161-72. [PMID: 22248306 DOI: 10.1517/17425255.2012.652084] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION The last two decades have brought many fundamental changes to the drug development process. One such change is the importance of preclinical pharmacokinetics, which has become an essential part of early drug discovery. Furthermore, bioanalytical methods have become more sensitive and the identification and quantitation of metabolites can now be carried out on limited amount of biological material. There has also been a change in regulatory expectations, which are now particularly focused on the safety of human metabolites. AREAS COVERED The focus of this paper is on some 'traditional' in vivo ADME studies: excretion balance, metabolic profile and WBA in the toxicological species. These studies, performed with radiolabeled material, have a long history: and are a regular presence in submission dossiers. This paper reviews their value in the perspective of the contemporary drug development process. EXPERT OPINION These experiments may sometimes still be relevant to explain toxicological findings or for other special purposes but should not be considered required pieces of the registration dossiers. An appropriate investigation of samples coming from safety evaluation and human Phase I studies and the knowledge generated during the lead optimization phase provide, in most instances, all the DMPK information needed to take decisions in the drug development process.
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