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Allerton CMN, Arcari JT, Aschenbrenner LM, Avery M, Bechle BM, Behzadi MA, Boras B, Buzon LM, Cardin RD, Catlin NR, Carlo AA, Coffman KJ, Dantonio A, Di L, Eng H, Farley KA, Ferre RA, Gernhardt SS, Gibson SA, Greasley SE, Greenfield SR, Hurst BL, Kalgutkar AS, Kimoto E, Lanyon LF, Lovett GH, Lian Y, Liu W, Martínez Alsina LA, Noell S, Obach RS, Owen DR, Patel NC, Rai DK, Reese MR, Rothan HA, Sakata S, Sammons MF, Sathish JG, Sharma R, Steppan CM, Tuttle JB, Verhoest PR, Wei L, Yang Q, Yurgelonis I, Zhu Y. A Second-Generation Oral SARS-CoV-2 Main Protease Inhibitor Clinical Candidate for the Treatment of COVID-19. J Med Chem 2024. [PMID: 38687966 DOI: 10.1021/acs.jmedchem.3c02469] [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: 05/02/2024]
Abstract
Despite the record-breaking discovery, development and approval of vaccines and antiviral therapeutics such as Paxlovid, coronavirus disease 2019 (COVID-19) remained the fourth leading cause of death in the world and third highest in the United States in 2022. Here, we report the discovery and characterization of PF-07817883, a second-generation, orally bioavailable, SARS-CoV-2 main protease inhibitor with improved metabolic stability versus nirmatrelvir, the antiviral component of the ritonavir-boosted therapy Paxlovid. We demonstrate the in vitro pan-human coronavirus antiviral activity and off-target selectivity profile of PF-07817883. PF-07817883 also demonstrated oral efficacy in a mouse-adapted SARS-CoV-2 model at plasma concentrations equivalent to nirmatrelvir. The preclinical in vivo pharmacokinetics and metabolism studies in human matrices are suggestive of improved oral pharmacokinetics for PF-07817883 in humans, relative to nirmatrelvir. In vitro inhibition/induction studies against major human drug metabolizing enzymes/transporters suggest a low potential for perpetrator drug-drug interactions upon single-agent use of PF-07817883.
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Affiliation(s)
| | - Joel T Arcari
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | | | - Melissa Avery
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Bruce M Bechle
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | | | - Britton Boras
- Pfizer Research & Development, La Jolla, California 92121, United States
| | - Leanne M Buzon
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Rhonda D Cardin
- Pfizer Research & Development, Pearl River, New York 10965, United States
| | - Natasha R Catlin
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Anthony A Carlo
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Karen J Coffman
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Alyssa Dantonio
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Li Di
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Heather Eng
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Kathleen A Farley
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Rose Ann Ferre
- Pfizer Research & Development, La Jolla, California 92121, United States
| | | | - Scott A Gibson
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, Utah 84322, United States
| | | | | | - Brett L Hurst
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, Utah 84322, United States
| | - Amit S Kalgutkar
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Emi Kimoto
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Lorraine F Lanyon
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Gabrielle H Lovett
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Yajing Lian
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Wei Liu
- Pfizer Research & Development, La Jolla, California 92121, United States
| | | | - Stephen Noell
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - R Scott Obach
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Dafydd R Owen
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Nandini C Patel
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Devendra K Rai
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Matthew R Reese
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Hussin A Rothan
- Pfizer Research & Development, Pearl River, New York 10965, United States
| | - Sylvie Sakata
- Pfizer Research & Development, La Jolla, California 92121, United States
| | - Matthew F Sammons
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Jean G Sathish
- Pfizer Research & Development, Pearl River, New York 10965, United States
| | - Raman Sharma
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Claire M Steppan
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Jamison B Tuttle
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Patrick R Verhoest
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Liuqing Wei
- Pfizer Research & Development, Groton, Connecticut 06340, United States
| | - Qingyi Yang
- Pfizer Research & Development, Cambridge, Massachusetts 02139, United States
| | - Irina Yurgelonis
- Pfizer Research & Development, Pearl River, New York 10965, United States
| | - Yuao Zhu
- Pfizer Research & Development, Pearl River, New York 10965, United States
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2
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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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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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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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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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8
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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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Catlin NR, Willson CJ, Creasy DM, Rao DB, Kissling GE, McIntyre BS, Wyde M. Differentiating between Testicular Toxicity and Sexual Immaturity in Ortho-phthalaldehyde Inhalation Toxicity Studies in Rats and Mice. Toxicol Pathol 2018; 46:753-763. [PMID: 30259793 DOI: 10.1177/0192623318801790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Early deaths of young or juvenile animals (before sexual maturation is achieved) in routine regulatory safety studies present pathologists and toxicologists with the challenge of interpreting findings in the male reproductive tract. Additionally, the advent of toxicity testing regulations has resulted in a growing need for the use of juvenile animals in toxicology studies. Here, we present the reproductive toxicity findings from a 13-week inhalation toxicity study with ortho-phthalaldehyde (OPA) in male rats and mice as a case example for working through this challenging task. In this study with OPA, survival was significantly reduced in the two highest exposure concentrations of OPA tested. Early deaths and histopathological lesions in the testes and epididymides were generally also limited to these two highest exposure groups. Therefore, there was concern that peripubertal morphological features could be a confounding factor for the histopathological evaluation of exposure-related testicular and epididymal findings. Although it can be difficult to differentiate exposure-related effects from the normal morphological features defining peripubertal changes in the testes and epididymides in animals that die early in a toxicity study, the use of age-matched controls in this case study with OPA provided a reference and aided in the differentiation of these effects.
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Affiliation(s)
- Natasha R Catlin
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.,2 Current address: Pfizer Inc., Groton, Connecticut, USA
| | | | | | - Deepa B Rao
- 3 Integrated Laboratory Systems, Morrisville, North Carolina, USA.,5 Current address: Food and Drug Administration, Silver Spring, Maryland, USA
| | - Grace E Kissling
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Barry S McIntyre
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Michael Wyde
- 1 National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Catlin NR, Waidyanatha S, Black SR, Mathews JM, Snyder RW, Patel PR, Watson SL, Fennell TR. Disposition of tris(4-chlorophenyl)methanol and tris(4-chlorophenyl)methane in male and female Harlan Sprague Dawley rats and B6C3F1/N mice following oral and intravenous administration. Xenobiotica 2018; 49:484-494. [PMID: 29659319 DOI: 10.1080/00498254.2018.1463475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 10/17/2022]
Abstract
Tris(4-chlorophenyl)methane (TCPME) and tris(4-chlorophenyl)methanol (TCPMOH) have been detected in various biota and human tissues. The current studies were undertaken to investigate the disposition and metabolism of TCPME and TCPMOH in rats and mice. [14C]TCPME was well absorbed (≥66%) in male rats and mice following a single oral administration of 1, 10, or 100 mg/kg. The excretion of [14C]TCPME-derived radioactivity in urine (≤2.5%) and feces (≤18%) was low. The administered dose was retained in tissues (≥ 64%) with adipose containing the highest concentrations. The metabolism of TCPME was minimal. The disposition and metabolism of [14C]TCPME in females was similar to males. The time to reach maximum concentration was ≤7 h, the plasma elimination half-life was ≥31 h, and the bioavailability was ≥82% following a 10 mg/kg oral dose of [14C]TCPME in male rats and mice. The disposition of [14C]TCPMOH was similar to that of [14C]TCPME. Following an intravenous administration of [14C]TCPME or [14C]TCPMOH in male rats and mice, the pattern of disposition was similar to that of oral administration. In conclusion, both TCPME and TCPMOH are readily absorbed and highly bioavailable following a single oral administration pointing to importance of assessing the toxicity of these chemicals.
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Affiliation(s)
- Natasha R Catlin
- a National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - Suramya Waidyanatha
- a National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | | | | | | | - Purvi R Patel
- b RTI International , Research Triangle Park , NC , USA
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Catlin NR, Willson CJ, Stout M, Kissling GE, Waidyanatha S, Baker GL, Hayden BK, Wyde M. Evaluation of the respiratory tract toxicity of ortho-phthalaldehyde, a proposed alternative for the chemical disinfectant glutaraldehyde. Inhal Toxicol 2017; 29:414-427. [PMID: 29039228 DOI: 10.1080/08958378.2017.1390015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [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: 10/18/2022]
Abstract
ortho-Phthalaldehyde (OPA) is a high-level chemical disinfectant that is commonly used for chemical sterilization of dental and medical instruments as an alternative to glutaraldehyde, a known skin and respiratory sensitizer. Concern for safe levels of human exposure remains due to a lack of toxicity data as well as human case reports of skin and respiratory sensitization following OPA exposure. The present study evaluated the inhalational toxicity of OPA in Harlan Sprague-Dawley rats and B6C3F1/N mice. Groups of 10 male and female rats and mice were exposed to OPA by whole-body inhalation for 3 months at concentrations of 0 (control), 0.44, 0.88, 1.75, 3.5, or 7.0 ppm. Rats and mice developed a spectrum of lesions at sites of contact throughout the respiratory tract (nose, larynx, trachea, lung), as well as in the skin and eye, consistent with a severe irritant response. In general, histologic lesions (necrosis, inflammation, regeneration, hyperplasia and metaplasia) occurred at deeper sites within the respiratory tract with increasing exposure concentration. As a first site of contact, the nose exhibited the greatest response to OPA exposure and resulted in an increased incidence, severity and variety of lesions compared to a previous study of glutaraldehyde exposure at similar exposure concentrations. This increased response in the nasal cavity, combined with extensive lesions throughout the respiratory tract, provides concern for use of OPA as a replacement for glutaraldehyde as a high-level disinfectant.
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Affiliation(s)
- Natasha R Catlin
- a National Institute of Environmental Health Sciences, Research Triangle Park , Durham , NC , USA
| | - Cynthia J Willson
- b Integrated Laboratory Systems Inc , Research Triangle Park , NC , USA
| | - Matthew Stout
- a National Institute of Environmental Health Sciences, Research Triangle Park , Durham , NC , USA
| | - Grace E Kissling
- a National Institute of Environmental Health Sciences, Research Triangle Park , Durham , NC , USA
| | - Suramya Waidyanatha
- a National Institute of Environmental Health Sciences, Research Triangle Park , Durham , NC , USA
| | | | | | - Michael Wyde
- a National Institute of Environmental Health Sciences, Research Triangle Park , Durham , NC , USA
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12
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Catlin NR, Herbert R, Janardhan K, Hejtmancik MR, Fomby LM, Vallant M, Kissling GE, DeVito MJ. Dose-response assessment of the dermal toxicity of Virginia cedarwood oil in F344/N rats and B6C3F1/N mice. Food Chem Toxicol 2016; 98:159-168. [PMID: 27769849 DOI: 10.1016/j.fct.2016.10.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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] [Received: 07/13/2016] [Revised: 09/26/2016] [Accepted: 10/17/2016] [Indexed: 12/15/2022]
Abstract
Virginia cedarwood oil is widely used as a fragrance material in household and personal products and as a naturally derived pesticide alternative. Due to conflicting literature on dermal exposures in animals and humans, concern for safe levels of human exposure remains. The present study evaluated the toxicity of cedarwood oil applied dermally to F344/N rats and B6C3F1/N mice for 13 weeks. Groups of 10 male and female rats and mice received no treatment (untreated control) or were administered cedarwood oil in 95% aqueous ethanol dermally at concentrations ranging from 0% (vehicle control), 6.25%, 12.5%, 25%, 50%, and 100% (undiluted). Rats and mice developed extensive skin lesions at the site of application. Benchmark dose modeling (BMD) was performed for the significantly increased skin lesions observed in the rat, to provide perspective for risk assessment applications. Benchmark dose modeling levels (BMDL) of 0.65 to 2.1% and 1.2 to 4.4% (equivalent to 13 to 42 mg/kg and 24 to 48 mg/kg, respectively) cedarwood oil were calculated for the most sensitive endpoint of epidermal hyperplasia in female rats and chronic active inflammation in male rats, respectively. These BMDL levels coincide with reported use levels in cosmetics and pesticides, raising the concern for human exposure.
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Affiliation(s)
- Natasha R Catlin
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
| | - Ron Herbert
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | | | | | | | - Molly Vallant
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Grace E Kissling
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Michael J DeVito
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Abstract
The Society of Toxicologic Pathology (STP) Education Committee and the STP Reproductive Special Interest Group held a North Carolina regional meeting entitled, "Juvenile Toxicology: Relevance and Challenges for Toxicologists and Pathologists" on March 13, 2015, at the National Institute of Environmental Health Sciences/National Toxicology Program in Research Triangle Park, North Carolina. The purpose of this regional meeting was to familiarize attendees with the topic of juvenile toxicity testing and discuss its relevance to clinical pediatric medicine, regulatory perspectives, challenges of appropriate study design confronted by toxicologists, and challenges of histopathologic examination and interpretation of juvenile tissues faced by pathologists. The 1-day meeting was a success with over 60 attendees representing industry, government, research organizations, and academia.
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Affiliation(s)
| | - Natasha R Catlin
- Developmental and Reproductive Toxicology Group, Toxicology Branch, National Toxicology Program (NTP) Division, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Erin M Quist
- Reproductive Endocrinology Group, National Toxicology Program Laboratory (NTPL), and NTP Pathology Group, Cellular & Molecular Pathology Branch, NTP Division, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | | | - Darlene Dixon
- Molecular Pathogenesis Group, National Toxicology Program Laboratory (NTPL), Division of the NTP, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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14
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Catlin NR, Huse SM, Boekelheide K. The stage-specific testicular germ cell apoptotic response to low-dose X-irradiation and 2,5-hexanedione combined exposure. I: Validation of the laser capture microdissection method for qRT-PCR array application. Toxicol Pathol 2014; 42:1221-8. [PMID: 24717900 DOI: 10.1177/0192623314526319] [Citation(s) in RCA: 6] [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] [Indexed: 11/16/2022]
Abstract
Over the past decade, laser capture microdissection (LCM) has grown as a tool for gene expression profiling of small numbers of cells from tumor samples and of specific cell populations in complex tissues. LCM can be used to study toxicant effects on selected cell populations within the testis at different stages of spermatogenesis. There are several LCM-related hurdles to overcome, including issues inherent to the method itself, as well as biases that result from amplifying the LCM-isolated RNA. Many technical issues associated with the LCM method are addressed here, including increasing RNA yield and obtaining more accurate quantification of RNA yields. We optimized the LCM method optimized to generate RNA quantities sufficient for quantitative reverse transcription polymerase chain reaction (qRT-PCR) array analysis without amplification and were able to validate the method through direct comparison of results from unamplified and amplified RNA from individual samples. The addition of an amplification step for gene expression studies using LCM RNA resulted in a bias, especially for low abundance transcripts. Although the amplification bias was consistent across samples, researchers should use caution when comparing results generated from amplified and unamplified LCM RNA. Here, we have validated the use of LCM-derived RNA with the qRT-PCR array, improving our ability to investigate cell-type and stage-specific responses to toxicant exposures.
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Affiliation(s)
- Natasha R Catlin
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Susan M Huse
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Kim Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
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15
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Catlin NR, Huse SM, Boekelheide K. The stage-specific testicular germ cell apoptotic response to low-dose radiation and 2,5-hexanedione combined exposure. II: qRT-PCR array analysis reveals dose dependent adaptive alterations in the apoptotic pathway. Toxicol Pathol 2014; 42:1229-37. [PMID: 24670816 DOI: 10.1177/0192623314525689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 11/15/2022]
Abstract
Testicular effects of chemical mixtures may differ from those of the individual chemical constituents. This study assessed the co-exposure effects of the model germ cell- and Sertoli cell-specific toxicants, X-irradiation (x-ray), and 2,5-hexanedione (HD), respectively. In high-dose studies, HD has been shown to attenuate x-ray-induced germ cell apoptosis. Adult rats were exposed to different levels of x-ray (0.5 Gy, 1 Gy, and 2 Gy) or HD (0.33%), either alone or in combination. To assess cell type-specific attenuation of x-ray effects with HD co-exposure, we used laser capture microdissection (LCM) to enrich the targeted cell population and examine a panel of apoptosis-related transcripts using PCR arrays. The apoptosis PCR arrays identified significant dose-dependent treatment effects on several genes, with downregulation of death receptor 5 (DR5), Naip2, Sphk2, Casp7, Aven, Birc3, and upregulation of Fas. The greatest difference in transcript response to exposure was seen with 0.5 Gy x-ray exposure, and the attenuation effect seen with the combined high-dose x-ray and HD did not persist into the low-dose range. Examination of protein levels in staged tubules revealed a significant upregulation in DR5, following high-dose co-exposure. These results provide insight into the testis cell-specific apoptotic response to low-dose co-exposures of model testicular toxicants.
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Affiliation(s)
- Natasha R Catlin
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Susan M Huse
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Kim Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
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