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Campion SN, Bowman CJ, Fuchs A, Karanian D, Rana P, Cappon GD. Juvenile toxicity study of PF-07256472/recifercept, a recombinant human soluble fibroblast growth factor receptor 3, in 2-3-month-old cynomolgus monkeys. Birth Defects Res 2023; 115:348-356. [PMID: 36367445 DOI: 10.1002/bdr2.2124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/06/2022] [Accepted: 10/26/2022] [Indexed: 11/13/2022]
Abstract
Achondroplasia is an autosomal disorder caused by point mutation in the gene encoding fibroblast growth factor receptor 3 (FGFR3) and resulting in gain of function. Recifercept is a potential disease modifying treatment for achondroplasia and functions as a decoy protein that competes for ligands of the mutated FGFR3. Recifercept is intended to restore normal bone growth by preventing the mutated FGFR3 from negative inhibitory signaling in pediatric patients with achondroplasia. Here we evaluated the potential effects of twice weekly administration of recifercept to juvenile cynomolgus monkeys (approximately 3-months of age at the initiation of dosing) for 6-months. No adverse effects were noted in this study, identifying the high dose as the no-observed-adverse-effect-level and supporting the use of recifercept in pediatric patients from birth. Considering that juvenile toxicity studies in nonhuman primates are not frequently conducted, and when they are conducted they typically utilize animals ≥9 months of age, this study demonstrates the feasibility of executing a juvenile toxicity study in very young monkeys prior to weaning.
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Affiliation(s)
- Sarah N Campion
- Pfizer Worldwide Research, Development and Medical, Groton, Connecticut, USA
| | | | - Antje Fuchs
- Labcorp Early Development Services GmbH, Muenster, Germany
| | - David Karanian
- Pfizer Worldwide Research, Development and Medical, Groton, Connecticut, USA
| | - Payal Rana
- Pfizer Worldwide Research, Development and Medical, Groton, Connecticut, USA
| | - Gregg D Cappon
- Pfizer Worldwide Research, Development and Medical, Groton, Connecticut, USA
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2
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Bowman CJ, Becourt-Lhote N, Boulifard V, Cordts R, Corriol-Rohou S, Enright B, Erkman L, Harris J, Hartmann A, Hilpert J, Kervyn S, Mattson B, Morford L, Muller M, Powell M, Sobol Z, Srinivasan R, Stark C, Thompson KE, Turner KJ, Barrow P. Science-Based Approach to Harmonize Contraception Recommendations in Clinical Trials and Pharmaceutical Labels. Clin Pharmacol Ther 2023; 113:226-245. [PMID: 35388453 PMCID: PMC10083981 DOI: 10.1002/cpt.2602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 03/25/2022] [Indexed: 01/27/2023]
Abstract
This review presents a European Federation of Pharmaceutical Industries and Association/PreClinical Development Expert Group (EFPIA-PDEG) topic group consensus on a data-driven approach to harmonized contraception recommendations for clinical trial protocols and product labeling. There is no international agreement in pharmaceutical clinical trial protocols or product labeling on when/if female and/or male contraception is warranted and for how long after the last dose. This absence of consensus has resulted in different recommendations among regions. For most pharmaceuticals, contraception recommendations are generally based exclusively on nonclinical data and/or mechanism. For clinical trials, contraception is the default position and is maintained for women throughout clinical development, whereas appropriate information can justify removing male contraception. Conversely, contraception is only recommended in product labeling when warranted. A base case rationale is proposed for whether or not female and/or male contraception is/are warranted, using available genotoxicity and developmental toxicity data. Contraception is generally warranted for both male and female subjects treated with mutagenic pharmaceuticals. We propose as a starting point that contraception is not typically warranted when the margin is 10-fold or greater between clinical exposure at the maximum recommended human dose and exposure at the no observed adverse effect level (NOAEL) for purely aneugenic pharmaceuticals and for pharmaceuticals that induce fetal malformations or embryo-fetal lethality. Other factors are discussed, including contraception methods, pregnancy testing, drug clearance, options for managing the absence of a developmental toxicity NOAEL, drug-drug interactions, radiopharmaceuticals, and other drug modalities. Overall, we present a data-driven rationale that can serve as a basis for consistent contraception recommendations in clinical trials and in product labeling across regions.
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Affiliation(s)
- Christopher J Bowman
- Worldwide Research, Development, and Medical, Pfizer Inc, Groton, Connecticut, USA
| | | | | | - Rüdiger Cordts
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | | | - Brian Enright
- Preclinical Safety, AbbVie Inc., North Chicago, Illinois, USA
| | - Linda Erkman
- Preclinical Safety, Novartis Pharma, Basel, Switzerland
| | - Jayne Harris
- Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, UK
| | | | - Jan Hilpert
- Translational Medicine, Pharma Research and Early Development, Bayer AG, Berlin, Germany
| | | | | | | | | | - Marcy Powell
- GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Zhanna Sobol
- Merck & Co., Inc., West Point, Pennsylvania, USA
| | | | - Claudia Stark
- Preclinical Development, Pharma Research and Early Development, Bayer AG, Berlin, Germany
| | - Kary E Thompson
- Nonclinical Safety, Janssen Pharmaceuticals, Spring House, Pennsylvania, USA
| | - Katie J Turner
- Nonclinical Safety, Janssen Pharmaceuticals, Spring House, Pennsylvania, USA
| | - Paul Barrow
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd., Basel, Switzerland
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3
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Catlin NR, Bowman CJ, Campion SN, Lewis EM, Nowland WS, Stethem C, Cappon GD. The postnatal resolution of developmental toxicity induced by pharmacological diacylglycerol acyltransferase 2 (DGAT2) inhibition during gestation in rats. Toxicol Sci 2022; 189:225-236. [PMID: 35866640 DOI: 10.1093/toxsci/kfac077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ervogastat (PF-06865571) is a small molecule diacylglycerol acyltransferase 2 (DGAT2) inhibitor being developed for the oral treatment of non-alcoholic steatohepatitis (NASH) with liver fibrosis. DGAT2 is a key enzyme in triglyceride synthesis in tissues and in regulating energy metabolism. Fertility and developmental toxicity studies with ervogastat were conducted in female rats and rabbits. There were no effects on female rat fertility or rabbit embryo-fetal development. Administration of ervogastat to pregnant rats during organogenesis reduced fetal weight and caused higher incidences of bent bones in fetuses that were shown to resolve by postnatal day 28 and were therefore considered to be transient variations secondary to developmental delay. Extended dosing in rats through the end of gestation and lactation (pre- and post-natal development study) caused impaired skin development, reduced offspring viability and growth retardation. The spectrum of developmental effects in rats is consistent with the intended pharmacology (altered triglyceride metabolism) and the transient nature of the skeletal findings, along with the late gestational window of sensitivity for the effects on skin barrier development, reduce the concern for potential adverse developmental effects following unintended early gestational exposure to ervogastat in humans where treatment can be discontinued once pregnancy is determined.
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Affiliation(s)
- Natasha R Catlin
- Drug Safety Research, Development, & Medical, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Christopher J Bowman
- Drug Safety Research, Development, & Medical, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Sarah N Campion
- Drug Safety Research, Development, & Medical, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Elise M Lewis
- Charles River Laboratories, Inc, Safety Assessment, Horsham, PA, USA
| | - William S Nowland
- Drug Safety Research, Development, & Medical, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Christine Stethem
- Drug Safety Research, Development, & Medical, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Gregg D Cappon
- Drug Safety Research, Development, & Medical, Pfizer Worldwide Research & Development, Groton, CT, USA
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Buetow BS, Cappon GD, Aschenbrenner LM, Updyke L, Torti VR, Evans M, Dalton SR, Bailey S, Bowman CJ. Regulatory Experience Assessing the Carcinogenic Potential of a Monoclonal Antibody Inhibiting PCSK9, Bococizumab, Including a 2-Year Carcinogenicity Study in Rats. Int J Toxicol 2022; 41:389-401. [DOI: 10.1177/10915818221106397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bococizumab is an anti-PCSK9 monoclonal antibody that was intended for the treatment of hypercholesterolemia. After reviewing the 6-month rat toxicity study data, in which there was a low spontaneous tumor incidence, unrelated to bococizumab administration, the U.S. FDA granted a carcinogenicity waiver request based on a weight-of-evidence assessment of low carcinogenic risk. Subsequently, after reviewing 6-month rat toxicity study data from another anti-PCSK9 antibody, RN317, with a similar low tumor incidence (unrelated to RN317), the U.S. FDA rescinded the bococizumab carcinogenicity study waiver and requested a full 2-year rat carcinogenicity study be conducted. The resulting 2-year carcinogenicity study demonstrated no bococizumab-related increase in tumors, confirming the weight-of-evidence evaluation and alleviating concerns regarding the carcinogenic potential. Here we report the scientific and regulatory background that led to the request for a rat carcinogenicity study, the feedback on the design of the carcinogenicity study, and the results from this study which affirmed the original weight-of-evidence assessment of low carcinogenic risk.
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Affiliation(s)
| | | | | | | | | | | | - Shana R. Dalton
- Labcorp Early Development Laboratories Inc, Madison, WI, USA
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5
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Catlin NR, Cappon GD, Engel S, Rohde C, Nowland WS, Buitrago S, Scully I, Anderson AS, Bowman CJ. Maternal immunization with Group B Streptococcus six-valent polysaccharide conjugate vaccine supported by lack of toxicity in rat and rabbit fertility and developmental toxicity studies. Birth Defects Res 2021; 113:1343-1356. [PMID: 34516044 DOI: 10.1002/bdr2.1953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/19/2021] [Accepted: 08/31/2021] [Indexed: 11/09/2022]
Abstract
A maternal Group B Streptococcus (GBS) six-valent polysaccharide conjugate vaccine (GBS6) is being developed to protect neonates and infants up to 3 months of age through passive transfer of antibodies from the mother to the infant. Fertility and developmental toxicity studies were conducted in female Sprague Dawley rats and New Zealand White rabbits with GBS6 (20 μg capsular polysaccharide/serotype formulated with or without AlPO4 , the highest clinical dose). Females were administered the full human dose of the GBS6 formulation intramuscularly twice prior to mating and twice during gestation, to ensure that high antibody levels were maintained throughout gestation and lactation. Approximately, half of the rats and rabbits were evaluated at the end of gestation, and the remainder were evaluated at the end of lactation. Maternal blood for GBS6 serology, to measure antibody titers to the GBS6 antigens, was collected prior to the first dose, prior to mating, and at each necropsy. Blood for serology was also collected from offspring at the end of gestation and lactation. In both species, there was no evidence of vaccine-related effects on fertility, embryo-fetal development, or postnatal development of the offspring, supporting regulatory guidance that single-species evaluation would have been sufficient. Functional serum antibodies to all six serotypes in the vaccine were confirmed in maternal animals and functional serum antibodies to one or more of the six serotypes was also confirmed in some rat offspring and most of the rabbit offspring. The results of these studies supported the safety of GBS6 vaccine administration to pregnant women.
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Affiliation(s)
- Natasha R Catlin
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - Gregg D Cappon
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - Scott Engel
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - Cynthia Rohde
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Pearl River, New York, USA
| | - William S Nowland
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Groton, Connecticut, USA
| | - Sandra Buitrago
- Vaccine Research and Development, Pfizer Worldwide Research and Development, Pearl River, New York, USA
| | - Ingrid Scully
- Vaccine Research and Development, Pfizer Worldwide Research and Development, Pearl River, New York, USA
| | - Annaliesa S Anderson
- Vaccine Research and Development, Pfizer Worldwide Research and Development, Pearl River, New York, USA
| | - Christopher J Bowman
- Drug Safety Research and Development, Pfizer Worldwide Research and Development, Groton, Connecticut, USA
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6
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Bowman CJ, Bouressam M, Campion SN, Cappon GD, Catlin NR, Cutler MW, Diekmann J, Rohde CM, Sellers RS, Lindemann C. Lack of effects on female fertility and prenatal and postnatal offspring development in rats with BNT162b2, a mRNA-based COVID-19 vaccine. Reprod Toxicol 2021; 103:28-35. [PMID: 34058573 PMCID: PMC8163337 DOI: 10.1016/j.reprotox.2021.05.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 12/17/2022]
Abstract
BNT162b2 is a vaccine developed to prevent coronavirus disease 2019 (COVID-19). BNT162b2 is a lipid nanoparticle formulated nucleoside-modified messenger RNA (mRNA) encoding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein locked in its prefusion conformation. A developmental and reproductive toxicity study was conducted in rats according to international regulatory guidelines. The full human BNT162b2 dose of 30 μg mRNA/dose (>300 times the human dose on a mg/kg basis) was administered intramuscularly to 44 female rats 21 and 14 days prior to mating and on gestation days 9 and 20. Half of the rats were subject to cesarean section and full fetal examination at the end of gestation, and the other half were allowed to deliver and were monitored to the end of lactation. A robust neutralizing antibody response was confirmed prior to mating and at the end of gestation and lactation. The presence of neutralizing antibodies was also confirmed in fetuses and offspring. Nonadverse effects, related to the local injection site reaction, were noted in dams as expected from other animal studies and consistent with observations in humans. There were no effects of BNT162b2 on female mating performance, fertility, or any ovarian or uterine parameters nor on embryo-fetal or postnatal survival, growth, physical development or neurofunctional development in the offspring through the end of lactation. Together with the safety profile in nonpregnant people, this ICH-compliant nonclinical safety data supports study of BNT162b2 in women of childbearing potential and pregnant and lactating women.
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Affiliation(s)
- Christopher J Bowman
- Drug Safety Research and Development, Pfizer Worldwide Research, Development & Medical, Groton, CT, USA.
| | - Marie Bouressam
- Charles River Laboratories France Safety Assessmsent SAS, Lyon, France
| | - Sarah N Campion
- Drug Safety Research and Development, Pfizer Worldwide Research, Development & Medical, Groton, CT, USA
| | - Gregg D Cappon
- Drug Safety Research and Development, Pfizer Worldwide Research, Development & Medical, Groton, CT, USA
| | - Natasha R Catlin
- Drug Safety Research and Development, Pfizer Worldwide Research, Development & Medical, Groton, CT, USA
| | - Mark W Cutler
- Vaccine Research and Development, Pfizer Worldwide Research, Development & Medical, Pearl River, NY, USA
| | - Jan Diekmann
- Non-Clinical Safety, BioNTech SE, Mainz, Germany
| | - Cynthia M Rohde
- Drug Safety Research and Development, Pfizer Worldwide Research, Development & Medical, Pearl River, NY, USA
| | - Rani S Sellers
- Drug Safety Research and Development, Pfizer Worldwide Research, Development & Medical, Pearl River, NY, USA
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7
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Kramer SP, Bowman CJ, Wang ZJ, Sheahon KM, Nakakura EK, Cho SJ, Umetsu SE, Behr SC. Hybrid Low-Grade Fibromyxoid Sarcoma and Sclerosing Epithelioid Fibrosarcoma of the Pancreas. J Gastrointest Cancer 2021; 51:1025-1029. [PMID: 32034641 DOI: 10.1007/s12029-020-00369-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Sage P Kramer
- Department of Radiology and Biomedical Imaging, UCSF Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA
| | | | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, UCSF Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA
| | | | - Eric K Nakakura
- Division of General Surgery, UCSF Medical Center, CA, San Francisco, USA
| | - Soo-Jin Cho
- Department of Pathology, UCSF Medical Center, San Francisco, CA, USA
| | - Sarah E Umetsu
- Department of Pathology, UCSF Medical Center, San Francisco, CA, USA
| | - Spencer C Behr
- Department of Radiology and Biomedical Imaging, UCSF Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA.
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8
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Catlin NR, Stethem C, Bowman CJ, Campion SN, Nowland WS, Cappon GD. Knockout mouse models are predictive of malformations or embryo-fetal death in drug safety evaluations. Reprod Toxicol 2021; 99:138-143. [PMID: 33065206 DOI: 10.1016/j.reprotox.2020.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Traditionally, understanding potential developmental toxicity from pharmaceutical exposures has been based on the results of ICH guideline studies in two species. However, support is growing for the use of weight of evidence approaches when communicating the risk of developmental toxicity, where the intended pharmacologic mode of action affects fundamental pathways in developmental biology or phenotypic data from genetically modified animals may increasingly be included in the overall assessment. Since some concern surrounds the use of data from knockout (KO) mice to accurately predict the risk for pharmaceutical modulation of a target, a deeper understanding of the relevance and predictivity of adverse developmental effects in KO mice for pharmacological target modulation is needed. To this end, we compared the results of embryo-fetal development (EFD) studies for 86 drugs approved by the FDA from 2017 to 2019 that also had KO mouse data available in the public domain. These comparisons demonstrate that data from KO mouse models are overall highly predictive of malformations or embryo-fetal lethality (MEFL) from EFD studies, but less so of a negative outcome in EFD studies. This information supports the use of embryo-fetal toxicity data in KO models as part of weight of evidence approaches in the communication of developmental toxicity risk of pharmaceutical compounds.
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Catlin NR, Bowman CJ, Campion SN, Davenport SD, Esler WP, Kumpf SW, Lewis EM, Nowland WS, Ross TT, Stedman DS, Stethem C, Cappon GD. Inhibition of ACC causes malformations in rats and rabbits: comparison of mammalian findings and alternative assays. Toxicol Sci 2020; 179:183-194. [PMID: 33247737 DOI: 10.1093/toxsci/kfaa169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Acetyl-CoA carboxylase (ACC) is an enzyme within the de novo lipogenesis (DNL) pathway and plays a role in regulating lipid metabolism. Pharmacologic ACC inhibition has been an area of interest for multiple potential indications including oncology, acne vulgaris, metabolic diseases such as type 2 diabetes mellitus, and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. A critical role for ACC in de novo synthesis of long-chain fatty acids during fetal development has been demonstrated in studies in mice lacking Acc1, where the absence of Acc1 results in early embryonic lethality. Following positive predictions of developmental toxicity in alternative in vitro assays (positive in murine embryonic stem cell [mESC] assay and rat whole embryo culture, but negative in zebrafish), developmental toxicity (growth retardation and dysmorphogenesis associated with disrupted midline fusion) was observed with the oral administration of the dual ACC1 and 2 inhibitor, PF-05175157, in Sprague Dawley rats and New Zealand White rabbits. The results of these studies are presented here to make comparisons across the assays, as well as mechanistic insights from the mESC assay demonstrating high ACC expression in the mESC and that ACC induced developmental toxicity can be rescued with palmitic acid providing supportive evidence for DNL pathway inhibition as the underlying mechanism. Ultimately, while the battery of alternative approaches and weight-of-evidence case were useful for hazard identification, the embryo-fetal development studies were necessary to inform the risk assessment on the adverse fetal response, as malformations and/or embryo fetal lethality were limited to doses that caused near complete inhibition of DNL.
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Affiliation(s)
- Natasha R Catlin
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Christopher J Bowman
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Sarah N Campion
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Scott D Davenport
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - William P Esler
- Internal Medicine Research Unit, Pfizer Worldwide Research & Development, Cambridge, MA, USA
| | - Steven W Kumpf
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Elise M Lewis
- Charles River Laboratories, Inc, Safety Assessment, Horsham, PA, USA
| | - William S Nowland
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Trenton T Ross
- Internal Medicine Research Unit, Pfizer Worldwide Research & Development, Cambridge, MA, USA
| | - Donald S Stedman
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Christine Stethem
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
| | - Gregg D Cappon
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT, USA
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Catlin NR, Stethem CM, Bowman CJ, Campion SN, Nowland WS, Cappon GD. Knockout mouse models are predictive of malformations or embryo-fetal death in drug safety evaluations. Reprod Toxicol 2020; 96:11-16. [PMID: 32522587 DOI: 10.1016/j.reprotox.2020.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 05/11/2020] [Accepted: 06/01/2020] [Indexed: 10/24/2022]
Abstract
Traditionally, understanding potential developmental toxicity from pharmaceutical exposures has been based on the results of ICH guideline studies in two species. However, support is growing for the use of weight of evidence approaches when communicating the risk of developmental toxicity, where the intended pharmacologic mode of action affects fundamental pathways in developmental biology or phenotypic data from genetically modified animals may increasingly be included in the overall assessment. Since some concern surrounds the use of data from knockout (KO) mice to accurately predict the risk for pharmaceutical modulation of a target, a deeper understanding of the relevance and predictivity of adverse developmental effects in KO mice for pharmacological target modulation is needed. To this end, we compared the results of embryo-fetal development (EFD) studies for 86 drugs approved by the FDA from 2017 to 2019 that also had KO mouse data available in the public domain. These comparisons demonstrate that data from KO mouse models are overall highly predictive of malformations or embryo-fetal lethality (MEFL) from EFD studies, but less so of a negative outcome in EFD studies. This information supports the use of embryo-fetal toxicity data in KO models as part of weight of evidence approaches in the communication of developmental toxicity risk of pharmaceutical compounds.
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11
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Catlin NR, Mitchell AZ, Potchoiba MJ, O'Hara DM, Wang M, Zhang M, Weinbauer GF, Bowman CJ. Placental transfer of 125 iodinated humanized immunoglobulin G2Δa in the cynomolgus monkey. Birth Defects Res 2019; 112:105-117. [PMID: 31746560 DOI: 10.1002/bdr2.1615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/09/2019] [Accepted: 10/26/2019] [Indexed: 12/30/2022]
Abstract
Antibody-like biopharmaceuticals cross the placenta by utilizing existing transport pathways (e.g., FcRn receptor). There are limited data evaluating this transfer during organogenesis in any species. Understanding placental transfer of antibody-like biopharmaceuticals can help to predict risk of developmental toxicity across species, including humans. To complement previously published placental transfer data in the rat with humanized IgGΔ2 (hIgG2), the timing and magnitude of transfer in the cynomolgus monkey and embryo/fetal biodistribution of maternally administered 125 I-radiolabeled hIgG2 was quantified on gestation days (GD) 35, 40, 50, 70, and 140 using gamma counting and whole body autoradiography 24 hr following intravenous injection. Chorioallantoic placental tissues were collected at all time points for Western Blot analysis with anti-FcRn antibody. Maternally administered 125 I-hIgG2 was found in embryo/fetal tissues at all time points, including organogenesis. Embryo/fetal plasma 125 I-hIgG2 concentration increased during gestation, but only slightly up to GD 70 in embryo/fetal tissues, with hIgG2 tissue concentrations generally similar between GD70 and 140. The embryo/fetal:maternal 125 I-hIgG2 plasma concentration ratio was approximately 2.3 fold higher on GD 140, in comparison to ratios on GD 40. Importantly, placental FcRn protein expression was confirmed at all timepoints. These data demonstrate placental transfer of hIgG2 in a nonhuman primate model, and at levels comparable to the rat model, raising the potential for adverse developmental outcomes by direct antibody binding to biological targets.
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Rocca M, Morford LL, Blanset DL, Halpern WG, Cavagnaro J, Bowman CJ. Applying a weight of evidence approach to the evaluation of developmental toxicity of biopharmaceuticals. Regul Toxicol Pharmacol 2018; 98:69-79. [PMID: 30009863 DOI: 10.1016/j.yrtph.2018.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 01/17/2023]
Abstract
Toxicity studies in pregnant animals are not always necessary for assessing the human risk of developmental toxicity of biopharmaceuticals. The growing experience and information on target biology and molecule-specific pharmacokinetics present a powerful approach to accurately anticipate effects of target engagement by biopharmaceuticals using a weight of evidence approach. The weight of evidence assessment should include all available data including target biology, pharmacokinetics, class effects, genetically modified animals, human mutations, and a thorough literature review. When assimilated, this weight of evidence evaluation may be sufficient to inform risk for specific clinical indications and patient populations. While under current guidance this approach is only applicable for drugs and biologics for oncology, the authors would like to suggest that this approach may also be appropriate for other disease indications. When there is an unacceptable level of uncertainty and a toxicity study in pregnant animals could impact human risk assessment, then such studies should be considered. Determination of appropriate nonclinical species for developmental toxicity studies to inform human risk should consider species-specific limitations, reproductive physiology, and pharmacology of the biopharmaceutical. This paper will provide considerations and examples of the weight of evidence approach to evaluating the human risk of developmental toxicity of biopharmaceuticals.
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Affiliation(s)
| | | | | | - Wendy G Halpern
- Genentech, A Member of the Roche Group, South San Francisco, CA, United States.
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Collinge M, Ball DJ, Bowman CJ, Nilson AL, Radi ZA, Vogel WM. Immunologic effects of chronic administration of tofacitinib, a Janus kinase inhibitor, in cynomolgus monkeys and rats - Comparison of juvenile and adult responses. Regul Toxicol Pharmacol 2018; 94:306-322. [PMID: 29454012 DOI: 10.1016/j.yrtph.2018.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 01/25/2023]
Abstract
Tofacitinib, an oral Janus kinase (JAK) inhibitor for treatment of rheumatoid arthritis, targets JAK1, JAK3, and to a lesser extent JAK2 and TYK2. JAK1/3 inhibition impairs gamma common chain cytokine receptor signaling, important in lymphocyte development, homeostasis and function. Adult and juvenile cynomolgus monkey and rat studies were conducted and the impact of tofacitinib on immune parameters (lymphoid tissues and lymphocyte subsets) and function (T-dependent antibody response (TDAR), mitogen-induced T cell proliferation) assessed. Tofacitinib administration decreased circulating T cells and NK cells in juvenile and adult animals of both species. B cell decreases were observed only in rats. These changes and decreased lymphoid tissue cellularity are consistent with the expected pharmacology of tofacitinib. No differences were observed between juvenile and adult animals, either in terms of doses at which effects were observed or differential effects on immune endpoints. Lymphomas were observed in three adult monkeys. Tofacitinib impaired the primary TDAR in juvenile monkeys, although a recall response was generated. Complete or partial reversal of the effects on the immune system was observed.
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Affiliation(s)
- Mark Collinge
- Pfizer Worldwide Research and Development, Drug Safety R&D, Eastern Point Road, Groton, CT 06340, USA.
| | - Douglas J Ball
- Pfizer Worldwide Research and Development, Drug Safety R&D, Eastern Point Road, Groton, CT 06340, USA
| | - Christopher J Bowman
- Pfizer Worldwide Research and Development, Drug Safety R&D, Eastern Point Road, Groton, CT 06340, USA
| | - Andrea L Nilson
- Pfizer Worldwide Research and Development, Drug Safety R&D, Eastern Point Road, Groton, CT 06340, USA
| | - Zaher A Radi
- Pfizer Worldwide Research and Development, Drug Safety R&D, One Portland Street, Cambridge, MA 02139, USA
| | - W Mark Vogel
- Pfizer Worldwide Research and Development, Drug Safety R&D, One Portland Street, Cambridge, MA 02139, USA
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Wu SP, Cooper BT, Bu F, Bowman CJ, Killian JK, Serrano J, Wang S, Jackson TM, Gorovets D, Shukla N, Meyers PA, Pisapia DJ, Gorlick R, Ladanyi M, Thomas K, Snuderl M, Karajannis MA. DNA Methylation-Based Classifier for Accurate Molecular Diagnosis of Bone Sarcomas. JCO Precis Oncol 2017; 2017. [PMID: 29354796 DOI: 10.1200/po.17.00031] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose Pediatric sarcomas provide a unique diagnostic challenge. There is considerable morphologic overlap between entities, increasing the importance of molecular studies in the diagnosis, treatment, and identification of therapeutic targets. We developed and validated a genome-wide DNA methylation based classifier to differentiate between osteosarcoma, Ewing's sarcoma, and synovial sarcoma. Materials and Methods DNA methylation status of 482,421 CpG sites in 10 Ewing's sarcoma, 11 synovial sarcoma, and 15 osteosarcoma samples were determined using the Illumina Infinium HumanMethylation450 array. We developed a random forest classifier trained from the 400 most differentially methylated CpG sites within the training set of 36 sarcoma samples. This classifier was validated on data drawn from The Cancer Genome Atlas (TCGA) synovial sarcoma, TARGET Osteosarcoma, and a recently published series of Ewing's sarcoma. Results Methylation profiling revealed three distinct patterns, each enriched with a single sarcoma subtype. Within the validation cohorts, all samples from TCGA were accurately classified as synovial sarcoma (10/10, sensitivity and specificity 100%), all but one sample from TARGET-OS were classified as osteosarcoma (85/86, sensitivity 98%, specificity 100%) and 14/15 Ewing's sarcoma samples classified correctly (sensitivity 93%, specificity 100%). The single misclassified osteosarcoma sample demonstrated high EWSR1 and ETV1 expression on RNA-seq although no fusion was found on manual curation of the transcript sequence. Two additional clinical samples, that were difficult to classify by morphology and molecular methods, were classified as osteosarcoma when previously suspected to be a synovial sarcoma and Ewing's sarcoma on initial diagnosis, respectively. Conclusion Osteosarcoma, synovial sarcoma, and Ewing's sarcoma have distinct epigenetic profiles. Our validated methylation-based classifier can be used to provide diagnostic assistance when histological and standard techniques are inconclusive.
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Affiliation(s)
- S Peter Wu
- Department of Radiation Oncology, NYU Langone Medical Center, New York, NY
| | - Benjamin T Cooper
- Department of Radiation Oncology, NYU Langone Medical Center, New York, NY
| | - Fang Bu
- Department of Pathology, NYU Langone Medical Center, New York, NY
| | | | - J Keith Killian
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Jonathan Serrano
- Department of Pathology, NYU Langone Medical Center, New York, NY
| | - Shiyang Wang
- Department of Pediatrics, NYU Langone Medical Center, New York, NY
| | - Twana M Jackson
- Department of Pediatrics, NYU Langone Medical Center, New York, NY
| | - Daniel Gorovets
- Department of Radiation Oncology, NYU Langone Medical Center, New York, NY
| | - Neerav Shukla
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Paul A Meyers
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - David J Pisapia
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY
| | - Richard Gorlick
- Department of Pediatrics, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY
| | - Marc Ladanyi
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Kristen Thomas
- Department of Pathology, NYU Langone Medical Center, New York, NY
| | - Matija Snuderl
- Department of Pathology, NYU Langone Medical Center, New York, NY
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15
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Bowman CJ, Barrow PC. Morphological variations in animal studies: Useful for human risk assessment, or Red Herring? Reprod Toxicol 2017. [DOI: 10.1016/j.reprotox.2017.06.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Lilja KC, Zhang N, Magli A, Gunduz V, Bowman CJ, Arpke RW, Darabi R, Kyba M, Perlingeiro R, Dynlacht BD. Pax7 remodels the chromatin landscape in skeletal muscle stem cells. PLoS One 2017; 12:e0176190. [PMID: 28441415 PMCID: PMC5404880 DOI: 10.1371/journal.pone.0176190] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/06/2017] [Indexed: 12/21/2022] Open
Abstract
Pluripotent stem cells (PSC) hold great promise for the treatment of human skeletal muscle diseases. However, it remains challenging to convert PSC to skeletal muscle cells, and the mechanisms by which the master regulatory transcription factor, Pax7, promotes muscle stem (satellite) cell identity are not yet understood. We have taken advantage of PSC-derived skeletal muscle precursor cells (iPax7), wherein the induced expression of Pax7 robustly initiates the muscle program and enables the in vitro generation of precursors that seed the satellite cell compartment upon transplantation. Remarkably, we found that chromatin accessibility in myogenic precursors pre-figures subsequent activation of myogenic differentiation genes. We also found that Pax7 binding is generally restricted to euchromatic regions and excluded from H3K27 tri-methylated regions in muscle cells, suggesting that recruitment of this factor is circumscribed by chromatin state. Further, we show that Pax7 binding induces dramatic, localized remodeling of chromatin characterized by the acquisition of histone marks associated with enhancer activity and induction of chromatin accessibility in both muscle precursors and lineage-committed myoblasts. Conversely, removal of Pax7 leads to rapid reversal of these features on a subset of enhancers. Interestingly, another cluster of Pax7 binding sites is associated with a durably accessible and remodeled chromatin state after removal of Pax7, and persistent enhancer accessibility is associated with subsequent, proximal binding by the muscle regulatory factors, MyoD1 and myogenin. Our studies provide new insights into the epigenetic landscape of skeletal muscle stem cells and precursors and the role of Pax7 in satellite cell specification.
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Affiliation(s)
- Karin C. Lilja
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Nan Zhang
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Alessandro Magli
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Volkan Gunduz
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Christopher J. Bowman
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, New York, United States of America
| | - Robert W. Arpke
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Radbod Darabi
- The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Michael Kyba
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States of America
| | - Rita Perlingeiro
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Brian D. Dynlacht
- Department of Pathology, New York University Cancer Institute, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
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17
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Bowman CJ, Chapin RE. Goldilocks’ Determination of What New In Vivo Data are “Just Right” for Different Common Drug Development Scenarios, Part 1. ACTA ACUST UNITED AC 2016; 107:185-194. [DOI: 10.1002/bdrb.21184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 07/29/2016] [Indexed: 12/28/2022]
Affiliation(s)
| | - Robert E Chapin
- Developmental and Reproductive Toxicology CoE; Pfizer, Inc; Groton CT USA
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18
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Halpern WG, Ameri M, Bowman CJ, Elwell MR, Mirsky ML, Oliver J, Regan KS, Remick AK, Sutherland VL, Thompson KE, Tremblay C, Yoshida M, Tomlinson L. Scientific and Regulatory Policy Committee Points to Consider Review: Inclusion of Reproductive and Pathology End Points for Assessment of Reproductive and Developmental Toxicity in Pharmaceutical Drug Development. Toxicol Pathol 2016; 44:789-809. [PMID: 27235322 PMCID: PMC4979743 DOI: 10.1177/0192623316650052] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Standard components of nonclinical toxicity testing for novel pharmaceuticals include clinical and anatomic pathology, as well as separate evaluation of effects on reproduction and development to inform clinical development and labeling. General study designs in regulatory guidances do not specifically mandate use of pathology or reproductive end points across all study types; thus, inclusion and use of these end points are variable. The Scientific and Regulatory Policy Committee of the Society of Toxicologic Pathology (STP) formed a Working Group to assess the current guidelines and practices on the use of reproductive, anatomic pathology, and clinical pathology end points in general, reproductive, and developmental toxicology studies. The Working Group constructed a survey sent to pathologists and reproductive toxicologists, and responses from participating organizations were collected through the STP for evaluation by the Working Group. The regulatory context, relevant survey results, and collective experience of the Working Group are discussed and provide the basis of each assessment by study type. Overall, the current practice of including specific end points on a case-by-case basis is considered appropriate. Points to consider are summarized for inclusion of reproductive end points in general toxicity studies and for the informed use of pathology end points in reproductive and developmental toxicity studies.
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Affiliation(s)
| | | | | | | | | | | | | | - Amera K Remick
- WIL Research, a Charles River Company, Hillsborough, North Carolina, USA
| | | | | | | | - Midori Yoshida
- Food Safety Commission of Japan, Minato-ku, Tokyo, Japan
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19
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Thorn M, Hudson AW, Kreeger J, Kawabe TT, Bowman CJ, Collinge M. Evaluation of a novel delayed-type hypersensitivity assay toCandida albicansin adult and neonatal rats. J Immunotoxicol 2014; 12:350-60. [DOI: 10.3109/1547691x.2014.980925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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20
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Butt M, Evans M, Bowman CJ, Cummings T, Oneda S, Shelton D, Zorbas M. Morphologic, stereologic, and morphometric evaluation of the nervous system in young cynomolgus monkeys (Macaca fascicularis) following maternal administration of tanezumab, a monoclonal antibody to nerve growth factor. Toxicol Sci 2014; 142:463-76. [PMID: 25326242 DOI: 10.1093/toxsci/kfu192] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Tanezumab, an antibody to nerve growth factor, was administered to pregnant cynomolgus monkeys at 0, 0.5, 4, and 30 mg/kg weekly, beginning gestation day (GD) 20 through parturition (∼GD165). Maternal tanezumab administration appeared to increase stillbirths and infant mortality, but no consistent pattern of gross and/or microscopic change was detected to explain the mortality. Offspring exposed in utero were evaluated at 12 months of age using light microscopy (all tissues), stereology (basal forebrain cholinergic and dorsal root ganglia neurons), and morphometry (sural nerve). Light microscopy revealed decreased number of neurons in sympathetic ganglia (superior mesenteric, cervicothoracic, and ganglia in the thoracic sympathetic trunk). Stereologic assessment indicated an overall decrease in dorsal root ganglion (thoracic) volume and number of neurons in animals exposed to tanezumab 4 mg/kg (n = 9) and 30 mg/kg (n = 1). At all tanezumab doses, the sural nerve was small due to decreases in myelinated and unmyelinated axons. Existing axons/myelin sheaths appeared normal when viewed with light and transmission electron microscopy. There was no indication of tanezumab-related, active neuron/nerve fiber degeneration/necrosis in any tissue, indicating decreased sensory/sympathetic neurons and axonal changes were due to hypoplasia or atrophy. These changes in the sensory and sympathetic portions of the peripheral nervous system suggest some degree of developmental neurotoxicity, although what effect, if any, the changes had on normal function and survival was not apparent. Overall, these changes were consistent with published data from rodent studies.
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Affiliation(s)
- Mark Butt
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
| | - Mark Evans
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
| | - Christopher J Bowman
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
| | - Thomas Cummings
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
| | - Satoru Oneda
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
| | - David Shelton
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
| | - Mark Zorbas
- *Tox Path Specialists, LLC, Frederick, Maryland 21701, Pfizer Inc., San Diego, California 92121, Pfizer Inc, Groton, Connecticut 06340, SNBL USA, Ltd., Everett, Washington 98203, and Pfizer Inc, South San Francisco, California 94080
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21
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Bowman CJ, Evans M, Cummings T, Oneda S, Butt M, Hurst S, Gremminger JL, Shelton D, Kamperschroer C, Zorbas M. Developmental toxicity assessment of tanezumab, an anti-nerve growth factor monoclonal antibody, in cynomolgus monkeys (Macaca fascicularis). Reprod Toxicol 2014; 53:105-18. [PMID: 25461901 DOI: 10.1016/j.reprotox.2014.10.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/11/2014] [Accepted: 10/05/2014] [Indexed: 01/03/2023]
Abstract
Two intravenous studies with tanezumab, an anti-nerve growth factor monoclonal antibody, were conducted in pregnant cynomolgus monkeys to assess potential effects on pregnancy and pre- and postnatal development. Study 1 evaluated infants up to 12 months of age following weekly maternal dosing (0, 0.5, 4 or 30 mg/kg; 18 per group) from gestation day (GD) 20 through parturition. Study 2 evaluated infants 2 months postnatally following weekly maternal dosing (0, 0.5 or 30 mg/kg; 20-21 per group) from GD 20 through 48. In the absence of maternal toxicity, tanezumab increased stillbirth and post-birth infant mortality/morbidity, decreased infant growth and resulted in microscopic changes in the peripheral sympathetic and sensory nervous system of the infants at all doses. Decreased primary antibody responses and increased incidences in skin changes in infants were also observed. The no-observed-adverse-effect-level for maternal toxicity was 30 mg/kg and <0.5 mg/kg for developmental toxicity.
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Affiliation(s)
| | | | | | | | - Mark Butt
- Tox Path Specialists, Frederick, MD, USA.
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22
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Bowman CJ, Evans M, Cummings T, Oneda S, Butt M, Hurst S, Gremminger JL, Shelton D, Kamperschroer C, Zorbas M. Developmental toxicity assessment of tanezumab, an anti-nerve growth factor monoclonal antibody, in Cynomolgus monkeys (Macaca fascicularis). Reprod Toxicol 2014. [DOI: 10.1016/j.reprotox.2014.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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Giragossian C, Clark T, Piché-Nicholas N, Bowman CJ. Neonatal Fc receptor and its role in the absorption, distribution, metabolism and excretion of immunoglobulin G-based biotherapeutics. Curr Drug Metab 2014; 14:764-90. [PMID: 23952252 DOI: 10.2174/13892002113149990099] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 01/29/2013] [Accepted: 02/13/2013] [Indexed: 11/22/2022]
Abstract
The neonatal Fc receptor (FcRn) is a heterodimeric membrane associated protein expressed in a variety of endothelial, epithelial and hematopoietic cells. FcRn regulates pH dependent intracellular trafficking of immunoglobulin G (IgG) and albumin, resulting in enhanced serum persistence and transcellular permeability of these proteins compared to other proteins of similar size. FcRn confers passive immunity during the early stages of life by facilitating maternal transmission of antibodies during gestation, and in some species during the neonatal period. The receptor continues to contribute to immunity beyond the perinatal period and throughout life by providing immunosurveillance in intestinal, pulmonary and genitourinary mucosa. In this capacity, FcRn facilitates bidirectional transport of IgG across mucosa and intracellular trafficking of antigen-antibody complexes in antigen presenting cells. Based on the functional roles of FcRn in regulating serum persistence and transcellular permeability, protein engineers have sought to exploit this receptor as a means of enhancing the absorption, distribution, metabolism and excretion (ADME) of IgG-based therapeutics. In this review, the current state of knowledge regarding the structural, mechanistic and functional properties of FcRn, as they relate to the ADME of IgG-based therapeutics, are discussed.
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Affiliation(s)
- Craig Giragossian
- Pharmacokinetics, Dynamics, and Drug Metabolism, Pfizer Global Research and Development, Groton, CT, USA.
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24
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Bowman CJ, Breslin WJ, Connor AV, Martin PL, Moffat GJ, Sivaraman L, Tornesi MB, Chivers S. Placental Transfer of Fc-Containing Biopharmaceuticals across Species, an Industry Survey Analysis. ACTA ACUST UNITED AC 2014; 98:459-85. [DOI: 10.1002/bdrb.21089] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/15/2013] [Indexed: 12/16/2022]
Affiliation(s)
| | | | | | | | | | - Lakshmi Sivaraman
- Bristol-Myers Squibb Company Research and Development; New Brunswick New Jersey
| | | | - Simon Chivers
- Novartis Institute for Biomedical Research; Basel Switzerland
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25
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Coder PS, Thomas JA, Stedman DB, Bowman CJ. Placental transfer of (125)Iodinated humanized immunoglobulin G2Δa in the Sprague Dawley rat. Reprod Toxicol 2013; 38:37-46. [PMID: 23462583 DOI: 10.1016/j.reprotox.2013.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/12/2013] [Accepted: 02/16/2013] [Indexed: 01/19/2023]
Abstract
Antibody-like biopharmaceuticals cross the placenta by utilizing transport pathways available for transfer of maternal antibodies to the conceptus. To characterize the timing and magnitude of this transfer in the rat, embryo/fetal biodistribution of maternally administered radiolabeled humanized IgG2 was quantified over the course of gestation using gamma counting and whole body autoradiography. The result was humanized IgG2 found in rat embryo/fetal tissues as early as gestation day 11 with a >1000-fold increase in the amount of total IgG2 by day 21. The concentration of IgG2 in rat embryo/fetal tissues generally remained unchanged from gestation day 11 to 17 with a slight increase from day 17 to 21. In addition, fetal-maternal tissue concentration ratios remained stable during organogenesis with a slight increase from gestation day 17 to 21. Based on the empirical amount of antibody present in the embryo/fetus during specific developmental windows, direct antibody binding to biological targets could potentially result in adverse developmental outcomes.
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Affiliation(s)
- P S Coder
- WIL Research, 1407 George Road, Ashland, OH, United States
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26
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Thorn M, Piche-Nicholas N, Stedman D, Davenport SW, Zhang N, Collinge M, Bowman CJ. Embryo-fetal transfer of bevacizumab (Avastin) in the rat over the course of gestation and the impact of neonatal Fc receptor (FcRn) binding. ACTA ACUST UNITED AC 2012; 95:363-75. [PMID: 22969064 DOI: 10.1002/bdrb.21026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 08/21/2012] [Indexed: 01/06/2023]
Abstract
BACKGROUND There is concern about embryo-fetal exposure to antibody-based biopharmaceuticals based on the increase of such therapies being prescribed to women of childbearing potential. Therefore, there is a desire to better characterize embryo-fetal exposure of these molecules. The pregnant rat is a standard model for evaluating the potential consequences of exposure but placental transfer of antibody-based biopharmaceuticals is not well understood in this model. METHODS The relative embryo-fetal distribution of an antibody-based biopharmaceutical was evaluated in the rat. Bevacizumab (Avastin) was chosen as a tool antibody since it does not have significant target binding in the rat that might influence embryo-fetal biodistribution. Avastin was labeled with a fluorescent dye, characterized, and injected into pregnant rats at different gestation ages. Labeled Avastin in fetal tissues was visualized ex vivo using an IVIS 200 (Caliper, A PerkinElmer Company, Alameda, CA). RESULTS Avastin localized to the fetus as early as 24-hr post intravenous injection of the dam, and was taken up by the fetus in a dose-dependent manner. Avastin was detectable in the developing embryo as early as gestation day 13 and continued to be transferred until the end of gestation. Fetal transfer of Avastins mutated in the portion of the antibody that binds the neonatal Fc receptor (FcRn) was tested in late gestation and was found to correlate with affinities of the mutant Avastin antibody to FcRn. CONCLUSIONS The novel application of this imaging technology was used to characterize the onset and duration of Avastin maternal-fetal transfer in rats and the importance of FcRn binding.
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Affiliation(s)
- Mitchell Thorn
- Drug Safety Research & Development, Pfizer, Inc., Groton, CT 06340, USA
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27
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Cappon GD, Bowman CJ, Hurtt ME, Grantham LE. Object discrimination reversal as a method to assess cognitive impairment in nonhuman primate enhanced pre- and postnatal developmental (ePPND) studies: statistical power analysis. ACTA ACUST UNITED AC 2012; 95:354-62. [PMID: 22930561 DOI: 10.1002/bdrb.21025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 08/08/2012] [Indexed: 11/08/2022]
Abstract
An important aspect of the enhanced pre- and postnatal developmental (ePPND) toxicity study in nonhuman primates (NHP) is that it combines in utero and postnatal assessments in a single study. However, it is unclear if NHP ePPND studies are suitable to perform all of the evaluations incorporated into rodent PPND studies. To understand the value of including cognitive assessment in a NHP ePPND toxicity study, we performed a power analysis of object discrimination reversal task data using a modified Wisconsin General Testing Apparatus (ODR-WGTA) from two NHP ePPND studies. ODR-WGTA endpoints evaluated were days to learning and to first reversal, and number of reversals. With α = 0.05 and a one-sided t-test, a sample of seven provided 80% power to predict a 100% increase in all three of the ODR-WGTA endpoints; a sample of 25 provided 80% power to predict a 50% increase. Similar power analyses were performed with data from the Cincinnati Water Maze (CWM) and passive avoidance tests from three rat PPND toxicity studies. Groups of 5 and 15 in the CWM and passive avoidance test, respectively, provided 80% power to detect a 100% change. While the power of the CWM is not far superior to the NHP ODR-WGTA, a clear advantage is the routine use of larger sample size, with a group of 20 rats the CWM provides ~90% power to detect a 50% change. Due to the limitations on the number of animals, the ODR-WGTA may not be suitable for assessing cognitive impairment in NHP ePPND studies.
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Affiliation(s)
- Gregg D Cappon
- Worldwide Research & Development, Pfizer Inc., Groton, CT 06340, USA.
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Cross DM, Chmielewski G, Lewis EM, Liu L, Modesitt MS, Ripp SL, Sawaryn CM, Bowman CJ. Non-clinical safety assessment and toxicokinetics of voriconazole and anidulafungin in the juvenile rat: A combination study design in support of a Paediatric Investigation Plan. Regul Toxicol Pharmacol 2012; 63:29-39. [DOI: 10.1016/j.yrtph.2012.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 02/08/2012] [Accepted: 02/08/2012] [Indexed: 10/28/2022]
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Coburn AM, Cappon GD, Bowman CJ, Stedman DB, Patyna S. Reproductive Toxicity Assessment of Sunitinib, A Multitargeted Receptor Tyrosine Kinase Inhibitor, in Male and Female Rats. ACTA ACUST UNITED AC 2012; 95:267-75. [DOI: 10.1002/bdrb.21012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 02/27/2012] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Shem Patyna
- Pfizer Worldwide Research and Development; San Diego; CA
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Campion SN, Davenport SJ, Nowland WS, Cappon GD, Bowman CJ, Hurtt ME. Sensitive windows of skeletal development in rabbits determined by hydroxyurea exposure at different times throughout gestation. ACTA ACUST UNITED AC 2012; 95:238-49. [PMID: 22495808 DOI: 10.1002/bdrb.21013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 02/27/2012] [Indexed: 11/07/2022]
Abstract
The critical periods of axial skeletal development in rats and mice have been well characterized, however the timing of skeletal development in rabbits is not as well known. It is important to have a more precise understanding of this timing of axial skeletal development in rabbits due to the common use of this species in standard nonclinical studies to assess embryo-fetal developmental toxicity. Hydroxyurea, a teratogen known to induce a variety of fetal skeletal malformations, was administered to New Zealand White rabbits as a single dose (500 mg/kg) on individual days during gestation (gestation day, GD 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, or 19) and fetal external, visceral, and skeletal morphology was examined following cesarean sections on GD 29. A wide range of fetal skeletal effects was observed following hydroxyurea treatment, with a progression of malformations from anterior to posterior structures over time, as well as from proximal to distal structures over time. The sensitive window of axial skeletal development was determined to be GD 8 to 13, while disruption of appendicular and cranio-facial skeletal development occurred primarily from GD 11 to 16 and GD 11 to 12, respectively. The results of this study provide a better understanding of the critical developmental window for different segments of the rabbit skeleton, which will aid in the design of window studies to investigate teratogenicity in rabbits.
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Affiliation(s)
- Sarah N Campion
- Drug Safety Research and Development, Pfizer Worldwide Research & Development, Groton, CT 06340, USA.
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Campion SN, Bowman CJ, Cappon GD, Harrison A, Finch GL, Hurtt ME. Developmental Toxicity of Lersivirine in Rabbits when Administered throughout Organogenesis and when Limited to Sensitive Windows of Axial Skeletal Development. ACTA ACUST UNITED AC 2012; 95:250-61. [DOI: 10.1002/bdrb.21014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 02/27/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Sarah N. Campion
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Christopher J. Bowman
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Gregg D. Cappon
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Anthony Harrison
- Pharmacokinetics; Dynamics and Metabolism; Pfizer Worldwide Research & Development; Sandwich; UK
| | - Gregory L. Finch
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Mark E. Hurtt
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
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Cappon GD, Bowman CJ, Campion SN, Chmielewski G, Hurtt ME, Finch GL, Lewis EM. Developmental Toxicity Study of Lersivirine in Mice. ACTA ACUST UNITED AC 2012; 95:225-30. [DOI: 10.1002/bdrb.21008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 02/02/2012] [Accepted: 02/03/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Gregg D. Cappon
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Christopher J. Bowman
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Sarah N. Campion
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Gary Chmielewski
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Mark E. Hurtt
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Gregory L. Finch
- Drug Safety Research and Development; Pfizer Worldwide Research & Development; Groton; CT
| | - Elise M. Lewis
- Charles River Laboratories Preclinical Services; Horsham; PA
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DeSesso JM, Williams AL, Ahuja A, Bowman CJ, Hurtt ME. The placenta, transfer of immunoglobulins, and safety assessment of biopharmaceuticals in pregnancy. Crit Rev Toxicol 2012; 42:185-210. [PMID: 22348352 DOI: 10.3109/10408444.2011.653487] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Ripp SL, Aram JA, Bowman CJ, Chmielewski G, Conte U, Cross DM, Gao H, Lewis EM, Lin J, Liu P, Schlamm HT. Tissue distribution of anidulafungin in neonatal rats. ACTA ACUST UNITED AC 2012; 95:89-94. [PMID: 22311649 DOI: 10.1002/bdrb.20347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 10/15/2011] [Indexed: 11/08/2022]
Abstract
Anidulafungin, an echinocandin, is currently approved for treatment of fungal infections in adults. There is a high unmet medical need for treatment of fungal infections in neonatal patients, who may be at higher risk of infections involving bone, brain, and heart tissues. This in vivo preclinical study investigated anidulafungin distribution in plasma, bone, brain, and heart tissues in neonatal rats. Postnatal day (PND) 4 and PND 8 Fischer (F344/DuCrl) rats were dosed subcutaneously once with anidulafungin (10 mg/kg) or once daily for 5 days (PND 4-8). Plasma and tissue samples were collected and anidulafungin levels were measured by liquid chromatography-tandem mass spectrometry. The mean plasma Cmax and AUC0-24 values were consistent with single-dose plasma pharmacokinetics (dose normalized) reported previously for adult rats. Observed bone concentrations were similar to plasma concentrations regardless of dosing duration, with bone-to-plasma concentration ratios of approximately 1.0. Heart concentrations were higher than plasma, with heart to plasma concentration ratios of 1.3- to 1.8-fold. Brain concentrations were low after single dose, with brain-to-plasma concentration ratio of approximately 0.23, but increased to approximately 0.71 after 5 days of dosing. Tissue concentrations were nearly identical after single-dose administration in both PND 4 and PND 8 animals, indicating that anidulafungin does not appear to differentially distribute in this period in neonatal rats. In conclusion, anidulafungin distributes to bone, brain, and heart tissues of neonatal rats; such results are supportive of further investigation of efficacy against infections involving bone, brain, and heart tissues.
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Affiliation(s)
- Sharon L Ripp
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, CT 06340, USA.
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Chapman KL, Andrews L, Bajramovic JJ, Baldrick P, Black LE, Bowman CJ, Buckley LA, Coney LA, Couch J, Maggie Dempster A, de Haan L, Jones K, Pullen N, de Boer AS, Sims J, Ian Ragan C. The design of chronic toxicology studies of monoclonal antibodies: implications for the reduction in use of non-human primates. Regul Toxicol Pharmacol 2011; 62:347-54. [PMID: 22100994 DOI: 10.1016/j.yrtph.2011.10.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 10/28/2011] [Indexed: 10/15/2022]
Abstract
The changing environment of monoclonal antibody (mAb) development is impacting on the cost of drug development and the use of experimental animals, particularly non-human primates (NHPs). The drive to reduce these costs is huge and involves rethinking and improving nonclinical studies to make them more efficient and more predictive of man. While NHP use might be unavoidable in many cases because of the exquisite specificity and consequent species selectivity of mAbs, our increasing knowledge base can be used to improve drug development and maximise the output of experimental data. Data on GLP regulatory toxicology studies for 58mAbs were obtained from 10 companies across a wide range of therapeutic indications. These data have been used to investigate current practice and identify study designs that minimise NHP use. Our analysis shows that there is variation in the number of animals used for similar studies. This information has been used to develop practical guidance and make recommendations on the use of science-based rationale to design studies using fewer animals taking into account the current regulatory guidance. There are eight recommendations intended to highlight areas for consideration. They include guidance on the main group size, the inclusion of recovery groups and the number of dose groups used in short and long term chronic toxicology studies.
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Affiliation(s)
- Kathryn L Chapman
- National Centre for Replacement, Refinement and Reduction of Animals in Research, Gibbs Building, 215 Euston Rd., London NW1 2BE, UK.
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Morford LL, Bowman CJ, Blanset DL, Bøgh IB, Chellman GJ, Halpern WG, Weinbauer GF, Coogan TP. Preclinical safety evaluations supporting pediatric drug development with biopharmaceuticals: strategy, challenges, current practices. ACTA ACUST UNITED AC 2011; 92:359-80. [PMID: 21770023 DOI: 10.1002/bdrb.20305] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 04/11/2011] [Indexed: 11/08/2022]
Abstract
Evaluation of pharmaceutical agents in children is now conducted earlier in the drug development process. An important consideration for this pediatric use is how to assess and support its safety. This article is a collaborative effort of industry toxicologists to review strategies, challenges, and current practice regarding preclinical safety evaluations supporting pediatric drug development with biopharmaceuticals. Biopharmaceuticals include a diverse group of molecular, cell-based or gene therapeutics derived from biological sources or complex biotechnological processes. The principles of preclinical support of pediatric drug development for biopharmaceuticals are similar to those for small molecule pharmaceuticals and in general follow the same regulatory guidances outlined by the Food and Drug Administration and European Medicines Agency. However, many biopharmaceuticals are also inherently different, with limited species specificity or immunogenic potential which may impact the approach taken. This article discusses several key areas to aid in the support of pediatric clinical use, study design considerations for juvenile toxicity studies when they are needed, and current practices to support pediatric drug development based on surveys specifically targeting biopharmaceutical development.
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Bowman CJ, Chmielewski G, Lewis E, Ripp S, Sawaryn CM, Cross DM. Juvenile toxicity assessment of anidulafungin in rats: an example of navigating case-by-case study design through scientific and regulatory challenges. ACTA ACUST UNITED AC 2011; 92:333-44. [PMID: 21594975 DOI: 10.1002/bdrb.20301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 04/06/2011] [Indexed: 11/08/2022]
Abstract
BACKGROUND Anidulafungin, an echinocandin antifungal marketed for adult use, is being considered for use in pediatric populations, including neonates. The evolution of the nonclinical pediatric safety strategy for anidulafungin serves as an example of case-by-case negotiation through the European Medicines Agency pediatric investigation plan process, resulting in an acceptable juvenile rat toxicity study. METHODS Study design challenges included animal selection, route, dose, age, and duration of dosing in relation to brain maturity, and appropriate study endpoints. The definitive study consisted of subcutaneous dosing at 0, 3, 10, and 30 mg/kg/day from postnatal day 4 to 62 (preterm infant to adulthood) with a 5-week recovery period. Study endpoints evaluated the potential for increased juvenile sensitivity to liver toxicity (seen in adults) and for novel toxicities in the central nervous system. RESULTS Anidulafungin-related effects included slightly reduced body weight, increased liver weight, and a mild decrease in red blood cell mass with increased reticulocyte count. There was no liver pathology and in the posttreatment phase there were no effects on neurological function. Following recovery, effects on body weight, hematology, and liver weight were reversing or reversed. CONCLUSIONS Therefore, the juvenile rat no-adverse-effect-level was 30 mg/kg/day. Exposures at this dose are similar to those achieved at the adult rat no-adverse-effect-level, suggesting that the juvenile rat is no more sensitive to anidulafungin than the adult rat. In conclusion, dialog and negotiation between the sponsor and the European Medicines Agency allowed for successful execution of a nonclinical safety strategy that enabled further clinical investigation of anidulafungin in pediatric populations.
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Affiliation(s)
- Christopher J Bowman
- Drug Safety Research & Development, Pfizer, Inc., Groton Laboratories, Eastern Point Rd., Groton, CT 06340, USA.
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Bowman CJ, Streck RD, Chapin RE. Maternal-placental insulin-like growth factor (IGF) signaling and its importance to normal embryo-fetal development. ACTA ACUST UNITED AC 2010; 89:339-49. [PMID: 20803692 DOI: 10.1002/bdrb.20249] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
As background for an antibody-based therapeutic program against the IGF receptor, we undertook a review of available information on the early pregnancy-specific regulation and localization of IGFs, IGF-binding proteins (BPs), IGFBP-specific proteases, and the type 1 IGF receptor relative to placental maintenance, function of placental nutrient transporters, placental cellular differentiation/turnover/apoptosis, and critical hormone signaling needed to maintain pregnancy. Possible adverse outcomes of altered IGF signaling include prenatal loss, fetal growth retardation, and maldevelopment are also discussed. It appears that the IGF axes in both the conceptus and mother are important for normal embryo-fetal growth. Thus, all molecules (i.e., both small and large) that disrupt the IGF axis could be expected to have some degree of fetal consequences.
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Affiliation(s)
- Christopher J Bowman
- Drug Safety Research and Development, Pfizer, Inc, Groton, Connecticut 06340, USA.
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Bowman CJ, Chmielewski G, Oneda S, Finco D, Boucher MA, Todd M. Embryo-fetal developmental toxicity of figitumumab, an anti-insulin-like growth factor-1 receptor (IGF-1R) monoclonal antibody, in cynomolgus monkeys. ACTA ACUST UNITED AC 2010; 89:326-38. [DOI: 10.1002/bdrb.20248] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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40
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Oztug Durer ZA, Cohlberg JA, Dinh P, Padua S, Ehrenclou K, Downes S, Tan JK, Nakano Y, Bowman CJ, Hoskins JL, Kwon C, Mason AZ, Rodriguez JA, Doucette PA, Shaw BF, Valentine JS. Loss of metal ions, disulfide reduction and mutations related to familial ALS promote formation of amyloid-like aggregates from superoxide dismutase. PLoS One 2009; 4:e5004. [PMID: 19325915 PMCID: PMC2659422 DOI: 10.1371/journal.pone.0005004] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 03/03/2009] [Indexed: 12/18/2022] Open
Abstract
Mutations in the gene encoding Cu-Zn superoxide dismutase (SOD1) are one of the causes of familial amyotrophic lateral sclerosis (FALS). Fibrillar inclusions containing SOD1 and SOD1 inclusions that bind the amyloid-specific dye thioflavin S have been found in neurons of transgenic mice expressing mutant SOD1. Therefore, the formation of amyloid fibrils from human SOD1 was investigated. When agitated at acidic pH in the presence of low concentrations of guanidine or acetonitrile, metalated SOD1 formed fibrillar material which bound both thioflavin T and Congo red and had circular dichroism and infrared spectra characteristic of amyloid. While metalated SOD1 did not form amyloid-like aggregates at neutral pH, either removing metals from SOD1 with its intramolecular disulfide bond intact or reducing the intramolecular disulfide bond of metalated SOD1 was sufficient to promote formation of these aggregates. SOD1 formed amyloid-like aggregates both with and without intermolecular disulfide bonds, depending on the incubation conditions, and a mutant SOD1 lacking free sulfhydryl groups (AS-SOD1) formed amyloid-like aggregates at neutral pH under reducing conditions. ALS mutations enhanced the ability of disulfide-reduced SOD1 to form amyloid-like aggregates, and apo-AS-SOD1 formed amyloid-like aggregates at pH 7 only when an ALS mutation was also present. These results indicate that some mutations related to ALS promote formation of amyloid-like aggregates by facilitating the loss of metals and/or by making the intramolecular disulfide bond more susceptible to reduction, thus allowing the conversion of SOD1 to a form that aggregates to form resembling amyloid. Furthermore, the occurrence of amyloid-like aggregates per se does not depend on forming intermolecular disulfide bonds, and multiple forms of such aggregates can be produced from SOD1.
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Affiliation(s)
- Zeynep A. Oztug Durer
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Jeffrey A. Cohlberg
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
- * E-mail:
| | - Phong Dinh
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Shelby Padua
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Krista Ehrenclou
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Sean Downes
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - James K. Tan
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Yoko Nakano
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Christopher J. Bowman
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California, United States of America
| | - Jessica L. Hoskins
- Department of Physics and Astronomy, California State University Long Beach, Long Beach, California, United States of America
| | - Chuhee Kwon
- Department of Physics and Astronomy, California State University Long Beach, Long Beach, California, United States of America
| | - Andrew Z. Mason
- Department of Biological Sciences, California State University Long Beach, Long Beach, California, United States of America
| | - Jorge A. Rodriguez
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Peter A. Doucette
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Bryan F. Shaw
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Joan Selverstone Valentine
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California, United States of America
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Bowman CJ, Turner KJ, Sar M, Barlow NJ, Gaido KW, Foster PMD. Altered Gene Expression During Rat Wolffian Duct Development following Di(n-Butyl) Phthalate Exposure. Toxicol Sci 2005; 86:161-74. [PMID: 15829613 DOI: 10.1093/toxsci/kfi172] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Di(n-butyl) phthalate (DBP) is a common plasticizer and solvent that disrupts androgen-dependent male reproductive development in rats. In utero exposure to 500 mg/kg/day DBP on gestation days (GD) 12 to 21 decreases androgen biosynthetic enzymes, resulting in decreased fetal testicular testosterone levels. One consequence of prenatal DBP exposure is malformed epididymides in adult rats. Reduced fetal testosterone levels may be responsible for the malformation, since testosterone is required for Wolffian duct stabilization and their development into epididymides. Currently, little is understood about the molecular mechanisms of Wolffian duct differentiation. The objective of this study was to identify changes in gene expression associated with altered morphology of the proximal Wolffian duct following in utero exposure to DBP. Pregnant Crl:CD(R) (SD) rats were gavaged with corn oil vehicle or 500 mg/kg/day DBP from GD 12 to GD 19 or 21. There were only small morphological differences between control and DBP-exposed Wolffian ducts on GD 19. On GD 21, 89% of male fetuses in the DBP dose group showed marked underdevelopment of Wolffian ducts, characterized by decreased coiling. RNA was isolated from Wolffian ducts on GD 19 and 21. Together with empirical information, cDNA microarrays were used to help identify candidate genes that could be associated with the morphological changes observed on GD 21. These candidate genes were analyzed by real-time RT-PCR. Changes in mRNA expression were observed in genes within the insulin-like growth factor (IGF) pathway, the matrix metalloproteinase (MMP) family, the extracellular matrix, and in other developmentally conserved signaling pathways. On GD 19, immunolocalization of IGF-1 receptor protein demonstrated an increase in cytoplasmic expression in the mesenchymal and epithelial cells. There was also a variable decrease in androgen receptor protein in ductal epithelial cells on GD 19. This study provides insight into the effects of antiandrogens on the molecular mechanisms involved in Wolffian duct development. The altered morphology and changes in gene expression following DBP exposure are suggestive of altered paracrine interactions between ductal epithelial cells and the surrounding mesenchyme during Wolffian duct differentiation due to lowered testosterone production.
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Affiliation(s)
- Christopher J Bowman
- CIIT Centers for Health Research, Research Triangle Park, North Carolina 27709, USA.
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Bowman CJ, Barlow NJ, Turner KJ, Wallace DG, Foster PMD. Effects of in utero exposure to finasteride on androgen-dependent reproductive development in the male rat. Toxicol Sci 2003; 74:393-406. [PMID: 12773767 DOI: 10.1093/toxsci/kfg128] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Finasteride is a specific inhibitor of type II 5alpha-reductase, the enzyme that converts testosterone (T) to the more potent androgen receptor agonist dihydrotestosterone (DHT). In utero exposure to androgen receptor antagonists and T biosynthesis inhibitors have induced permanent effects on androgen-sensitive end points such as anogenital distance (AGD), nipple retention, and malformations of the male rat reproductive tract. The objectives of this study were to (1) characterize the dose response of finasteride-mediated alterations in androgen-dependent developmental end points, (2) determine whether prenatal exposure to finasteride permanently decreases AGD or results in nipple retention, and (3) evaluate whether AGD or nipple retention is predictive of adverse alterations in the male reproductive tract. Pregnant Crl:CD(SD)BR rats (n=5-6/group) were gavaged with either vehicle or finasteride at 0.01, 0.1, 1.0, 10, or 100 mg/kg/day on gestation days 12 to 21. All male offspring were monitored individually until necropsy on postnatal day (PND) 90. The present study design has been used previously for other antiandrogens and is sensitive to perturbations of the male rat reproductive tract. Decreases in AGD on PND 1 and increases in areolae-nipple retention on PND 13 were significantly different from controls in all finasteride-exposed male rats. Finasteride-induced changes in AGD and nipple retention were permanent in male rats exposed to finasteride at and above 0.1 mg/kg/day. On PND 90, dorsolateral and ventral prostate lobes were absent in 21 to 24% of rats exposed to 100 mg/kg/day finasteride and weighed significantly less at and above 10 mg/kg/day. In the highest dose group, 73% of animals had ectopic testes, much higher than previously reported. The most sensitive malformation other than decreased AGD and nipple retention was the dose-dependent increase in hypospadias. The lowest observed adverse effect level (LOAEL) for finasteride-induced permanent effects in this study was 0.1 mg/kg/day based on permanent changes in AGD and nipple retention. Finasteride-induced changes in AGD and retention of nipples were highly predictive of hypospadias, ectopic testes, and prostate malformations even though some animals with retained nipples or decreased AGD may not have had other reproductive tract malformations. In summary, prenatal exposure to finasteride specifically inhibited DHT-mediated development with little to no change in T-mediated development.
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Affiliation(s)
- Christopher J Bowman
- CIIT Centers for Health Research, Research Triangle Park, North Carolina 27709, USA
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Turner KJ, McIntyre BS, Phillips SL, Barlow NJ, Bowman CJ, Foster PMD. Altered gene expression during rat Wolffian duct development in response to in utero exposure to the antiandrogen linuron. Toxicol Sci 2003; 74:114-28. [PMID: 12730624 DOI: 10.1093/toxsci/kfg096] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Linuron is an herbicide with weak androgen receptor (AR) antagonist activity. Exposure to linuron from gestation days (GD) 12 to 21 perturbs androgen-dependent male reproductive development. In utero exposure to 50-mg/kg/day linuron induces malformations of the epididymis and the vas deferens. The objective of this study was to identify alterations in gene expression within the testis and epididymis associated with abnormal Wolffian duct development and to correlate changes in gene expression with the gross morphology of the affected epididymides. Pregnant Sprague-Dawley rats were administered either corn oil vehicle or linuron (50 mg/kg/day) by gavage from GD 12 to 21 (n = 3-6 controls, n = 5-10 linuron-treated dams per time point). Changes in gene expression were evaluated in testes on GD 21 and in epididymides on GD 21 and postnatal day (PND) 7, using cDNA microarrays and confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) analyses. RNA was isolated from intact epididymides with reduced or no ductal coiling from the linuron groups, and epididymides with noncontiguous ducts were excluded. In the fetal testis, exposure to linuron did not result in reduced mRNA expression of the AR or that of several steroidogenic enzymes, supporting the hypothesis that linuron does not reduce fetal testosterone production. Linuron induced a significant decrease in AR mRNA expression in GD 21 epididymides. Significant changes in mRNA expression in GD 21 and PND 7 epididymides were also identified in the epidermal growth factor (EGF), insulin-like growth factor 1 (IGF-1), bone morphogenetic protein (BMP), fibroblast growth factor (FGF), and Notch signaling pathways. These pathways are involved in tissue morphogenesis. Changes in the expression of AR and IGF-1 receptors were detected by immunostaining in malformed epididymides from linuron-exposed rats. Linuron induced changes in epididymal gene expression suggestive of altered paracrine interactions between the mesenchyme and epithelial cells during development. The EGF, Notch, IGF-1, BMP4, and FGF signaling pathways may be involved in normal testosterone-mediated development of the Wolffian duct.
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MESH Headings
- Animals
- Animals, Newborn
- Bone Morphogenetic Protein 4
- Bone Morphogenetic Proteins/biosynthesis
- Epididymis/drug effects
- Epididymis/embryology
- Epididymis/metabolism
- Estrogen Antagonists/toxicity
- Female
- Fetus/metabolism
- Fibroblast Growth Factor 2/biosynthesis
- Gene Expression/drug effects
- Heparan Sulfate Proteoglycans/biosynthesis
- Herbicides/toxicity
- Immunohistochemistry
- Linuron/toxicity
- Male
- Oligonucleotide Array Sequence Analysis
- Pregnancy
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- Rats
- Receptor, IGF Type 1/biosynthesis
- Receptor, IGF Type 1/genetics
- Receptor, Notch2
- Receptors, Androgen/biosynthesis
- Receptors, Androgen/genetics
- Receptors, Cell Surface/biosynthesis
- Receptors, Opioid, delta/biosynthesis
- Reproduction/drug effects
- Reverse Transcriptase Polymerase Chain Reaction
- Testis/drug effects
- Testis/embryology
- Testis/metabolism
- Tissue Inhibitor of Metalloproteinase-3/biosynthesis
- Wolffian Ducts/drug effects
- Wolffian Ducts/embryology
- Wolffian Ducts/metabolism
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Affiliation(s)
- Katie J Turner
- CIIT Centers for Health Research, Research Triangle Park, North Carolina 27709-2137, USA.
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44
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Abstract
Vitellogenin (Vtg) and estrogen receptor (ER) gene expression levels were measured in largemouth bass to evaluate the activation of the ER-mediated pathway by estradiol (E(2)). Single injections of E(2) ranging from 0.0005 to 5 mg/kg up-regulated plasma Vtg in a dose-dependent manner. Vtg and ER mRNAs were measured using partial cDNA sequences corresponding to the C-terminal domain for Vtg and the ligand-binding domain of ER alpha sequences. After acute E(2)-exposures (2 mg/kg), Vtg and ER mRNAs and plasma Vtg levels peaked after 2 days. The rate of ER mRNA accumulation peaked 36-42 h earlier than Vtg mRNA. The expression window for ER defines the primary response to E(2) in largemouth bass and that for Vtg a delayed primary response. The specific effect of E(2) on other estrogen-regulated genes was tested during these same time windows using differential display RT-PCR. Specific up-regulated genes that are expressed in the same time window as Vtg were ERp72 (a membrane-bound disulfide isomerase) and a gene with homology to an expressed gene identified in zebrafish. Genes that were expressed in a pattern that mimics the ER include the gene for zona radiata protein ZP2, and a gene with homology to an expressed gene found in winter flounder. One gene for fibrinogen gamma was down-regulated and an unidentified gene was transiently up-regulated after 12 h of exposure and returned to basal levels by 48 h. Taken together these studies indicate that the acute molecular response to E(2) involves a complex network of responses over time.
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Affiliation(s)
- Christopher J Bowman
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, USA
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45
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Hemmer MJ, Bowman CJ, Hemmer BL, Friedman SD, Marcovich D, Kroll KJ, Denslow ND. Vitellogenin mRNA regulation and plasma clearance in male sheepshead minnows, (Cyprinodon variegatus) after cessation of exposure to 17 beta-estradiol and p-nonylphenol. Aquat Toxicol 2002; 58:99-112. [PMID: 12062157 DOI: 10.1016/s0166-445x(01)00238-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Research was conducted to determine the kinetics of hepatic vitellogenin (VTG) mRNA regulation and plasma VTG accumulation and clearance in male sheepshead minnows (Cyprinodon variegatus) during and after cessation of exposure to either 17 beta-estradiol (E2) or para-nonylphenol (NP). Adult fish were continuously exposed to aqueous measured concentrations of 0.089 and 0.71 microg E2 per l, and 5.6 and 59.6 microg NP per l for 16 days using an intermittent flow-through dosing apparatus. Fish were sampled on days 8 and 16 of exposure followed by sampling at discrete intervals for up to 96 days post-exposure. At each interval five fish were randomly sampled from each concentration and hepatic VTG mRNA and serum VTG levels for individual fish determined by slot blot and direct enzyme-linked immunosorbent assay (ELISA), respectively. Exposure to E2 and NP resulted in a dose dependent increase in hepatic VTG mRNA and plasma VTG over the course of the 16-day exposure period. Mean plasma VTG levels at day 16 were >100 mg/ml for both high doses of E2 and NP, and >20 mg/ml for the low exposure treatments. Within 8 days post-exposure, hepatic VTG mRNA levels returned to baseline in both high and low E2 treatments but remained elevated 2-4 fold in the NP treatments. Due to a shortened sampling period, a clearance rate for plasma VTG in the 5.6 microg NP per l treatment could not determined. In the 0.089, 0.71 microg E2 per l, and 59.6 microg NP per l treatments, VTG levels began decreasing within 4 days after exposure cessation and exhibited an exponential rate of elimination from plasma. Clearance rates for 0.71 microg E2 per l and 59.6 microg NP per l were not significantly different (P=0.47), however, both demonstrated significantly higher rates of clearance (P<0.02) than observed in the 0.089 microg E2 per l treatment. Our results indicate that hepatic VTG mRNA rapidly diminishes after cessation of estrogenic exposure in sheepshead minnows, but plasma VTG clearance is concentration and time dependent and may be detected at measurable levels for months after initial exposure to an estrogenic compound.
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Affiliation(s)
- Michael J Hemmer
- US Environmental Protection Agency, Gulf Ecology Division, 1 Sabine Island Drive, Gulf Breeze, FL 32561, USA.
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46
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Abstract
During the last decade there has been a significant body of research conducted on environmental estrogens. These include industrial, agricultural and pest-control chemicals that bind to the estrogen receptor and induce biological changes during development or reproduction. Most of these changes are probably due to modified gene expression, since estrogen receptors function at this level. We have mapped qualitative gene expression responses (by differential display reverse transcriptase polymerase chain reaction, DD) in adult male sheepshead minnows (Cyprinidon variegatus) receiving high dose injections (5 mg/kg), or constant flow-through aquatic exposures to environmentally relevant concentrations (100 ng/l) of estradiol-17beta, and found them nearly identical. We have observed both up-regulation and down-regulation of transcripts, which fit into known responses to estradiol. Among the genes up-regulated are vitellogenin and several vitelline envelope proteins indicating that genes for proteins involved in egg development and maturation are susceptible to environmental estrogen exposure. While physiological changes caused by estradiol treatment are not totally explained by changes at the mRNA level, those changes can nevertheless be used as fingerprints to characterize an in vivo estrogenic response.
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Affiliation(s)
- N D Denslow
- Department of Biochemistry and Molecular Biology, University of Florida, PO Box 100156 HC, 32610, Gainesville, FL, USA.
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47
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Denslow ND, Bowman CJ, Ferguson RJ, Lee HS, Hemmer MJ, Folmar LC. Induction of gene expression in sheepshead minnows (Cyprinodon variegatus) treated with 17beta-estradiol, diethylstilbestrol, or ethinylestradiol: the use of mRNA fingerprints as an indicator of gene regulation. Gen Comp Endocrinol 2001; 121:250-60. [PMID: 11254367 DOI: 10.1006/gcen.2001.7605] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The recent interest in hormonally active environmental contaminants has sparked a drive to find sensitive methods to measure their effects on wildlife. A molecular-based assay has been developed to measure the induction of gene expression in sheepshead minnows (Cyprinodon variegatus) exposed in vivo to the natural and pharmaceutical estrogens 17beta-estradiol, ethinylestradiol, and diethylstilbestrol. This method used differential display reverse transcriptase polymerase chain reaction assays to compare the expression of individual mRNAs from control and estrogen-exposed fish. Forty-eight differentially expressed cDNAs were isolated by this method, including cDNAs for vitelline envelope proteins and vitellogenin. The mRNA expression patterns for fish injected with a pharmacological dose of estradiol (5 mg/kg) were identical to those obtained in fish receiving constant aqueous exposure to 212 ng estradiol/liter. Further, the cDNA "fingerprint" pattern observed in the estradiol-treated fish also matched that obtained in fish receiving continuous-flow aqueous exposures to 192 ng ethinyl estradiol/liter and a nominal concentration of 200 ng diethylstilbestrol/liter. The results demonstrate a characteristic expression pattern for genes upregulated by exposure to a variety of natural and anthropogenic estrogens and suggest this approach may be valuable to examine the potential effects of environmental contaminants on other endocrine-mediated pathways of reproduction, growth, and development.
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Affiliation(s)
- N D Denslow
- Department of Biochemistry, University of Florida, Gainesville, Florida 32610, USA
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48
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Hemmer MJ, Hemmer BL, Bowman CJ, Kroll KJ, Folmar LC, Marcovich D, Hoglund MD, Denslow ND. Effects of p-nonylphenol, methoxychlor, and endosulfan on vitellogenin induction and expression in sheepshead minnow (Cyprinodon variegatus). Environ Toxicol Chem 2001; 20:336-343. [PMID: 11351433 DOI: 10.1897/1551-5028(2001)020<0336:eopnma>2.0.co;2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Temporal and dose-response relationships of vitellogenin (VTG) mRNA induction and subsequent plasma VTG accumulation were established for sheepshead minnows (Cyprinodon variegatus) treated with p-nonylphenol (an alkylphenol) and the organochlorine pesticides methoxychlor and endosulfan. Thirty-two adult male fish per treatment were continuously exposed to measured concentrations of 0.64, 5.4, 11.8, 23.3, and 42.7 micrograms/L p-nonylphenol; 1.1, 2.5, 5.6, 12.1, and 18.4 micrograms/L methoxychlor; and in two separate tests, 15.9, 36.3, 68.8, 162, 277, 403, 590, and 788 ng/L endosulfan using an intermittent flow-through dosing apparatus. Separate triethylene glycol (50 microliters/L) and 17 beta-estradiol (65.1 ng/L) treatments served as the negative and positive controls, respectively. Four fish were randomly sampled from each test concentration on days 2, 5, 13, 21, 35, and 42 of exposure, and levels of hepatic VTG mRNA induction and serum VTG accumulation were determined for each individual. Overall, fish exposed to p-nonylphenol or methoxychlor demonstrated a rapid, dose-dependent synthesis of VTG mRNA up to day 5 of exposure, followed by a relatively constant dose-dependent expression through day 42. Both chemicals showed a dose-dependent increase in plasma VTG over the entire time course of exposure, with significantly elevated VTG levels by the fifth day of exposure to p-nonylphenol at concentrations of 5.4 micrograms/L or greater and to methoxychlor at concentrations of 2.5 micrograms/L or greater. Exposure to 0.64 microgram/L p-nonylphenol resulted in highly variable plasma VTG levels of less than 6 mg/ml. Exposures with endosulfan failed to induce measurable levels of either hepatic VTG mRNA or serum VTG at the chemical concentrations tested. Our results demonstrate that the sheepshead minnow bioassay is a suitable estuarine/marine teleost model for in vivo screening of potentially estrogenic substances.
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Affiliation(s)
- M J Hemmer
- U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, 1 Sabine Island Drive, Gulf Breeze, Florida 32561, USA.
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49
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Abstract
Many environmentally persistent xenobiotic chemicals appear to disrupt normal endocrine function by acting as ligands for endogenous steroid receptors, including the estrogen receptor. Xenobiotics that bind to the estrogen receptor may elicit several effects, one of which is activating estrogen-responsive genes, such as vitellogenin (Vtg). Primers to vitellogenin mRNA have been used to amplify a portion of the coding sequence in sheepshead minnow (SHM) (Cyprinodon variegatus). Two Vtg cDNA fragments from SHM were isolated exhibiting 72% sequence homology and corresponding to the two Vtg genes identified in the mummichog, Fundulus heteroclitus. Using these Vtg cDNA fragments as sensitive genetic probes, we evaluated the initial estrogenic response of fish exposed to natural or anthropogenic chemicals. These probes were used to study in vivo gene induction in SHM exposed to 17beta-estradiol (E(2)) and ethinylestradiol (EE(2)) under controlled laboratory conditions. Hepatic Vtg mRNA was upregulated and plasma Vtg synthesis in estrogen-induced SHM was assessed. Two in vivo time-course experiments were conducted; a single injection of E(2) followed over 72 h and a double E(2) injection examined for 12 days. These two protocols provided evidence for differential hepatic Vtg mRNA regulation resulting from a single or a double injection. In a separate experiment using an aqueous flowthrough system, constant exposures to low doses of E(2) (200 ng/L) and EE(2) (100 ng/L) induced hepatic Vtg mRNA and plasma Vtg to levels comparable with the E(2) injections. Larger aqueous exposure doses (2000 ng/L E(2) or 1000 ng/L EE(2)) in the flowthrough experiment resulted in greater responses of hepatic Vtg mRNA and plasma Vtg at 7 days. Constant aqueous exposure to E(2) (2000 ng/L) or EE(2) (1000 ng/L) may thus be more effective than a single large-dose injection (5 mg/kg) to stimulate Vtg gene activation and synthesis.
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Affiliation(s)
- C J Bowman
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610, USA
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50
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Funkenstein B, Bowman CJ, Denslow ND, Cardinali M, Carnevali O. Contrasting effects of estrogen on transthyretin and vitellogenin expression in males of the marine fish, Sparus aurata. Mol Cell Endocrinol 2000; 167:33-41. [PMID: 11000518 DOI: 10.1016/s0303-7207(00)00301-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A partial cDNA encoding for the C-terminus of vitellogenin (VTG) was cloned from liver of Sparus aurata male treated with 17beta-estradiol (E(2)). E(2) treatment of S. aurata males resulted in increased synthesis and secretion of VTG protein into the plasma, determined by a specific enzyme-linked immunosorbent assay (ELISA) in a time-dependent manner. While VTG mRNA was induced by E(2) treatment, transthyretin (TTR) mRNA levels were reduced. These data provide the first demonstration that estrogen exhibits contrasting effect on VTG and on TTR gene expression in teleosts.
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Affiliation(s)
- B Funkenstein
- National Institute of Oceanography, Israel Oceanographic and Limnological Research, Tel Shikmona, PO Box 8030, 31080, Haifa, Israel.
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