Pub Date : 2024-10-19DOI: 10.1016/j.yrtph.2024.105726
Nicholas L. Drury , Robyn L. Prueitt , Barbara D. Beck
In November 2023, the International Agency for Research on Cancer (IARC) classified PFOA as “carcinogenic to humans” (Group 1) and PFOS as “possibly carcinogenic to humans” (Group 2B). We evaluated these classifications, considering the epidemiology, experimental animal, and mechanistic evidence. It is our opinion that the IARC Working Group overstated the available evidence for the carcinogenicity of PFOA and PFOS. Epidemiology studies have shown weak and inconsistent associations across studies. Studies reporting increased incidences of tumors in experimental animals exposed to PFOA or PFOS had statistically significant results that were driven by the presence of benign adenomas. The IARC Working Group used the key characteristics of carcinogens (KCCs, which comprise 10 chemical and/or biological properties of known human carcinogens) approach to upgrade the carcinogenicity classifications for PFOA and PFOS from initially lower classifications that were based on the strength of the epidemiology and experimental animal evidence. However, this is not a robust assessment of mechanistic evidence, as it fails to consider the quality, external validity, and relevance of the evidence. Rather than use the KCCs as a checklist of potential carcinogenic mechanisms, IARC should use a rigorous method to evaluate the plausibility and human relevance of mechanistic evidence.
{"title":"Commentary: Understanding IARC's PFOA and PFOS carcinogenicity assessments","authors":"Nicholas L. Drury , Robyn L. Prueitt , Barbara D. Beck","doi":"10.1016/j.yrtph.2024.105726","DOIUrl":"10.1016/j.yrtph.2024.105726","url":null,"abstract":"<div><div>In November 2023, the International Agency for Research on Cancer (IARC) classified PFOA as “carcinogenic to humans” (Group 1) and PFOS as “possibly carcinogenic to humans” (Group 2B). We evaluated these classifications, considering the epidemiology, experimental animal, and mechanistic evidence. It is our opinion that the IARC Working Group overstated the available evidence for the carcinogenicity of PFOA and PFOS. Epidemiology studies have shown weak and inconsistent associations across studies. Studies reporting increased incidences of tumors in experimental animals exposed to PFOA or PFOS had statistically significant results that were driven by the presence of benign adenomas. The IARC Working Group used the key characteristics of carcinogens (KCCs, which comprise 10 chemical and/or biological properties of known human carcinogens) approach to upgrade the carcinogenicity classifications for PFOA and PFOS from initially lower classifications that were based on the strength of the epidemiology and experimental animal evidence. However, this is not a robust assessment of mechanistic evidence, as it fails to consider the quality, external validity, and relevance of the evidence. Rather than use the KCCs as a checklist of potential carcinogenic mechanisms, IARC should use a rigorous method to evaluate the plausibility and human relevance of mechanistic evidence.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"154 ","pages":"Article 105726"},"PeriodicalIF":3.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142473311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.yrtph.2024.105724
Jürg A. Zarn, Sebastian L.B. König, Holly V. Shaw, H. Christoph Geiser
The concurrent control group is the most important reference for the interpretation of toxicity studies. However, pooled information on control animals from independent studies, i.e., historical control data (HCD), is also used for the interpretation of results. Currently, an overview on actual HCD use in regulatory toxicology is lacking. Therefore, we evaluated the HCD use of the Joint FAO/WHO Meeting on Pesticide Residues from 2004 to 2021 and compared it with recommendations in regulatory guidelines and in the literature. We found that HCD was used routinely and exclusively to avoid potential false positive decisions regarding the treatment-relatedness of effects, mostly using the HCD range, i.e., the most extreme values, as a benchmark. HCD were not used to avoid potential false negative decisions or for quality control of the index study. The central assumption of the HCD use, namely that the HCD and control group of the index study follow the same underlying distribution because they are samples of the same data generation process, was not investigated, although numerous factors potentially contribute to effect variation between the different control groups pooled in the HCD. We recommend that the existing guidelines be revised to improve the robustness and transparency of toxicological assessments.
{"title":"An analysis of the use of historical control data in the assessment of regulatory pesticide toxicity studies","authors":"Jürg A. Zarn, Sebastian L.B. König, Holly V. Shaw, H. Christoph Geiser","doi":"10.1016/j.yrtph.2024.105724","DOIUrl":"10.1016/j.yrtph.2024.105724","url":null,"abstract":"<div><div>The concurrent control group is the most important reference for the interpretation of toxicity studies. However, pooled information on control animals from independent studies, <em>i.e.</em>, historical control data (HCD), is also used for the interpretation of results. Currently, an overview on actual HCD use in regulatory toxicology is lacking. Therefore, we evaluated the HCD use of the Joint FAO/WHO Meeting on Pesticide Residues from 2004 to 2021 and compared it with recommendations in regulatory guidelines and in the literature. We found that HCD was used routinely and exclusively to avoid potential false positive decisions regarding the treatment-relatedness of effects, mostly using the HCD range, <em>i.e.,</em> the most extreme values, as a benchmark. HCD were not used to avoid potential false negative decisions or for quality control of the index study. The central assumption of the HCD use, namely that the HCD and control group of the index study follow the same underlying distribution because they are samples of the same data generation process, was not investigated, although numerous factors potentially contribute to effect variation between the different control groups pooled in the HCD. We recommend that the existing guidelines be revised to improve the robustness and transparency of toxicological assessments.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"154 ","pages":"Article 105724"},"PeriodicalIF":3.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142473315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-11DOI: 10.1016/j.yrtph.2024.105717
Sue A. Hubbard , Kevin Klipsch , Michael S. Cockburn , Sandra Carey
In this paper we present methodological and experimental details and results from an OECD Test Guideline 474 and GLP-compliant in vivo micronucleus study on sodium molybdate dihydrate in Sprague Dawley rats. Prior to the conduct of this study, there was a data-gap for reliable in vivo genotoxicity data for molybdenum substances. The presentation of the new study is complemented by a review of other available in vitro and in vivo data on the genotoxicity of molybdenum substances, focussing on substances where the contained or released molybdate ion, MoO42−, is considered the responsible moiety for any toxicological effect (grouping/category approach). After consideration of the relevance and reliability of all available data, the absence of a concern for genotoxicity of molybdate in vitro and in vivo is concluded.
{"title":"In vivo micronucleus assay on sodium molybdate in rats and its impact on the overall assessment of the genotoxicity of molybdenum substances","authors":"Sue A. Hubbard , Kevin Klipsch , Michael S. Cockburn , Sandra Carey","doi":"10.1016/j.yrtph.2024.105717","DOIUrl":"10.1016/j.yrtph.2024.105717","url":null,"abstract":"<div><div>In this paper we present methodological and experimental details and results from an OECD Test Guideline 474 and GLP-compliant <em>in vivo</em> micronucleus study on sodium molybdate dihydrate in Sprague Dawley rats. Prior to the conduct of this study, there was a data-gap for reliable <em>in vivo</em> genotoxicity data for molybdenum substances. The presentation of the new study is complemented by a review of other available <em>in vitro</em> and <em>in vivo</em> data on the genotoxicity of molybdenum substances, focussing on substances where the contained or released molybdate ion, MoO<sub>4</sub><sup>2−</sup>, is considered the responsible moiety for any toxicological effect (grouping/category approach). After consideration of the relevance and reliability of all available data, the absence of a concern for genotoxicity of molybdate <em>in vitro</em> and <em>in vivo</em> is concluded.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"154 ","pages":"Article 105717"},"PeriodicalIF":3.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142473313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.yrtph.2024.105716
Jerry Achar , James W. Firman , Chantelle Tran , Daniella Kim , Mark T.D. Cronin , Gunilla Öberg
Although uncertainties expressed in texts within QSAR studies can guide quantitative uncertainty estimations, they are often overlooked during uncertainty analysis. Using neurotoxicity as an example, this study developed a method to support analysis of implicitly and explicitly expressed uncertainties in QSAR modeling studies. Text content analysis was employed to identify implicit and explicit uncertainty indicators, whereafter uncertainties within the indicator-containing sentences were identified and systematically categorized according to 20 uncertainty sources. Our results show that implicit uncertainty was more frequent within most uncertainty sources (13/20), while explicit uncertainty was more frequent in only three sources, indicating that uncertainty is predominantly expressed implicitly in the field. The most highly cited sources included Mechanistic plausibility, Model relevance and Model performance, suggesting they constitute sources of most concern. The fact that other sources like Data balance were not mentioned, although it is recognized in the broader QSAR literature as an area of concern, demonstrates that the output from the type of analysis conducted here must be interpreted in the context of the broader QSAR literature before conclusions are drawn. Overall, the method established here can be applied in other QSAR modeling contexts and ultimately guide efforts targeted towards addressing the identified uncertainty sources.
{"title":"Analysis of implicit and explicit uncertainties in QSAR prediction of chemical toxicity: A case study of neurotoxicity","authors":"Jerry Achar , James W. Firman , Chantelle Tran , Daniella Kim , Mark T.D. Cronin , Gunilla Öberg","doi":"10.1016/j.yrtph.2024.105716","DOIUrl":"10.1016/j.yrtph.2024.105716","url":null,"abstract":"<div><div>Although uncertainties expressed in texts within QSAR studies can guide quantitative uncertainty estimations, they are often overlooked during uncertainty analysis. Using neurotoxicity as an example, this study developed a method to support analysis of implicitly and explicitly expressed uncertainties in QSAR modeling studies. Text content analysis was employed to identify implicit and explicit uncertainty indicators, whereafter uncertainties within the indicator-containing sentences were identified and systematically categorized according to 20 uncertainty sources. Our results show that implicit uncertainty was more frequent within most uncertainty sources (13/20), while explicit uncertainty was more frequent in only three sources, indicating that uncertainty is predominantly expressed implicitly in the field. The most highly cited sources included Mechanistic plausibility, Model relevance and Model performance, suggesting they constitute sources of most concern. The fact that other sources like Data balance were not mentioned, although it is recognized in the broader QSAR literature as an area of concern, demonstrates that the output from the type of analysis conducted here must be interpreted in the context of the broader QSAR literature before conclusions are drawn. Overall, the method established here can be applied in other QSAR modeling contexts and ultimately guide efforts targeted towards addressing the identified uncertainty sources.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"154 ","pages":"Article 105716"},"PeriodicalIF":3.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.yrtph.2024.105711
Chetan K. Kajavadara, Satyam N. Patel, Rushikesh M. Shukla, Darshan T. Valani, Rajesh J. Patel, Laxit K. Bhatt, Rajesh Sundar, Mukul R. Jain
The Ames test is a widely used bacterial mutagenicity assay to evaluate the potential of chemical compounds to induce mutations. In recent years, there has been growing concern regarding the presence of N-nitrosamines in pharmaceuticals, food, and other consumer products. N-Nitrosamines are probable mutagens and carcinogens. To address the reduced sensitivity of the standard Ames test for N-nitrosamines, particularly N-nitrosodimethylamine, the European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) have recently published recommendations for enhanced Ames test (EAT) conditions. However, there is a lack of clear guidance on the selection of N-nitrosamine positive control concentrations, particularly for 1-cyclopentyl-4-nitrosopiperazine, and the amount of solvent to be used in the EAT. This study aims to address the current gap in concentration and volume specifications by providing a comprehensive guide to set up enhanced Ames test conditions specifically for N-nitrosamine compounds using appropriate amounts of solvent, new solvents, and strain-specific positive control concentrations.
{"title":"Selection of solvent and positive control concentration for enhanced Ames test conditions for N-nitrosamine compounds","authors":"Chetan K. Kajavadara, Satyam N. Patel, Rushikesh M. Shukla, Darshan T. Valani, Rajesh J. Patel, Laxit K. Bhatt, Rajesh Sundar, Mukul R. Jain","doi":"10.1016/j.yrtph.2024.105711","DOIUrl":"10.1016/j.yrtph.2024.105711","url":null,"abstract":"<div><div>The Ames test is a widely used bacterial mutagenicity assay to evaluate the potential of chemical compounds to induce mutations. In recent years, there has been growing concern regarding the presence of N-nitrosamines in pharmaceuticals, food, and other consumer products. N-Nitrosamines are probable mutagens and carcinogens. To address the reduced sensitivity of the standard Ames test for N-nitrosamines, particularly N-nitrosodimethylamine, the European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) have recently published recommendations for enhanced Ames test (EAT) conditions. However, there is a lack of clear guidance on the selection of N-nitrosamine positive control concentrations, particularly for 1-cyclopentyl-4-nitrosopiperazine, and the amount of solvent to be used in the EAT. This study aims to address the current gap in concentration and volume specifications by providing a comprehensive guide to set up enhanced Ames test conditions specifically for N-nitrosamine compounds using appropriate amounts of solvent, new solvents, and strain-specific positive control concentrations.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"154 ","pages":"Article 105711"},"PeriodicalIF":3.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-05DOI: 10.1016/j.yrtph.2024.105715
Frank Liu
Drug impurities are undesirable but unavoidable chemicals which can occur throughout the drug life cycle. The safety implications of drug impurities can be significant given that they can impact safety, quality, and efficacy of drug products and that certain drug impurities are mutagenic, carcinogenic, or teratogenic. The characteristics of drug impurities could be specific to drug modalities (e.g., small molecules vs. biologics). The commonly encountered drug impurities include elemental impurity, residual solvent, organic impurity, host cell protein and DNA, residual viral vector, extractable and leachable, and particle. They can cause various adverse effects such as immunogenicity, infection, genotoxicity, and carcinogenicity upon significant exposure. Therefore, the effective control of these drug impurities is central for patient safety. Regulations and guidelines are available for drug developers to manage them. Their qualification is obtained based on authoritative qualification thresholds or safety assessment following the classic toxicological risk assessment. The current review focuses on the safety assessment science and methodology used for diverse types of drug impurities. Due to the different nature of diverse drug impurities, their safety assessment represents a significant challenge for drug developers.
{"title":"Safety assessment of drug impurities for patient safety: A comprehensive review","authors":"Frank Liu","doi":"10.1016/j.yrtph.2024.105715","DOIUrl":"10.1016/j.yrtph.2024.105715","url":null,"abstract":"<div><div>Drug impurities are undesirable but unavoidable chemicals which can occur throughout the drug life cycle. The safety implications of drug impurities can be significant given that they can impact safety, quality, and efficacy of drug products and that certain drug impurities are mutagenic, carcinogenic, or teratogenic. The characteristics of drug impurities could be specific to drug modalities (e.g., small molecules vs. biologics). The commonly encountered drug impurities include elemental impurity, residual solvent, organic impurity, host cell protein and DNA, residual viral vector, extractable and leachable, and particle. They can cause various adverse effects such as immunogenicity, infection, genotoxicity, and carcinogenicity upon significant exposure. Therefore, the effective control of these drug impurities is central for patient safety. Regulations and guidelines are available for drug developers to manage them. Their qualification is obtained based on authoritative qualification thresholds or safety assessment following the classic toxicological risk assessment. The current review focuses on the safety assessment science and methodology used for diverse types of drug impurities. Due to the different nature of diverse drug impurities, their safety assessment represents a significant challenge for drug developers.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"153 ","pages":"Article 105715"},"PeriodicalIF":3.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.yrtph.2024.105714
Adnan S. AL-Mussallam , Rawan S. Alshathri , Bart Desmedt , Fahad S. Aldawsari , Eric Deconinck , Omniyah A. Alharthi , Abdullah T. Bawazir
Fragrance chemicals are ubiquitous in cosmetics; however, they have been linked to allergic contact dermatitis. Allergy prevention involves two main strategies. Firstly, consumers are protected by limiting the maximum concentration of fragrance in a given product to avoid inducing allergies. Secondly, consumers who are already sensitized are protected by having the presence of such fragrance communicated to them. In this study, a validated GC-MS method was employed to quantify 26 allergens in 108 products marketed in Saudi Arabia.Additionally, a quantitative risk assessment (QRA) was performed on the studied cosmetics to determine the risk of inducing allergies. The results indicated that most allergens were present at acceptable concentrations, while 19 products carried a risk of inducing allergies. Furthermore, Lilial and Lyral, two prohibited fragrances, were detected in 97 products. It should be emphasized that this is the first study conducted in Saudi Arabia to evaluate the safety of the well-known 26 fragrance allergens. Hence, this study can potentially serve as a regional standard for future research.
{"title":"Quantitative risk assessments of skin sensitization for 26 allergens in different consumer products in the Saudi market","authors":"Adnan S. AL-Mussallam , Rawan S. Alshathri , Bart Desmedt , Fahad S. Aldawsari , Eric Deconinck , Omniyah A. Alharthi , Abdullah T. Bawazir","doi":"10.1016/j.yrtph.2024.105714","DOIUrl":"10.1016/j.yrtph.2024.105714","url":null,"abstract":"<div><div>Fragrance chemicals are ubiquitous in cosmetics; however, they have been linked to allergic contact dermatitis. Allergy prevention involves two main strategies. Firstly, consumers are protected by limiting the maximum concentration of fragrance in a given product to avoid inducing allergies. Secondly, consumers who are already sensitized are protected by having the presence of such fragrance communicated to them. In this study, a validated GC-MS method was employed to quantify 26 allergens in 108 products marketed in Saudi Arabia.Additionally, a quantitative risk assessment (QRA) was performed on the studied cosmetics to determine the risk of inducing allergies. The results indicated that most allergens were present at acceptable concentrations, while 19 products carried a risk of inducing allergies. Furthermore, Lilial and Lyral, two prohibited fragrances, were detected in 97 products. It should be emphasized that this is the first study conducted in Saudi Arabia to evaluate the safety of the well-known 26 fragrance allergens. Hence, this study can potentially serve as a regional standard for future research.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"153 ","pages":"Article 105714"},"PeriodicalIF":3.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142378217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.yrtph.2024.105713
Ting-Jung Ku , Tien-Chueh Kuo , Olivia A. Lin , Yufeng Jane Tseng
The escalating challenge of New Psychoactive Substances (NPS) necessitates enhanced global monitoring and analysis capabilities. This study introduces an advanced interactive visualization tool that employs Geographic Information System (GIS) technologies to improve the functionality of the UNODC's Early Warning Advisory. The tool enables dynamic observation and analysis of NPS's geographical and temporal distribution, thereby facilitating a comprehensive understanding of their public health impacts. By incorporating detailed choropleth maps and annual and cumulative bar charts, the tool allows policymakers and researchers to visually track and analyze trends in NPS usage and control efforts across different regions. The results demonstrate the tool's effectiveness in providing actionable insights, which support the strategic development of public health policies and interventions to curb the global rise in NPS usage. This initiative illustrates the essential role of digital tools in enhancing public health strategies and responses to emerging drug trends. This rising challenge underscores the urgent need for innovative solutions in monitoring drug trends, a theme explored in this paper. The web tool is available at https://nps-vis.cmdm.tw, and the code is available at https://github.com/CMDM-Lab/nps-vis.
{"title":"Mapping new psychoactive substances: Leveraging GIS technology for advanced global surveillance and policy support","authors":"Ting-Jung Ku , Tien-Chueh Kuo , Olivia A. Lin , Yufeng Jane Tseng","doi":"10.1016/j.yrtph.2024.105713","DOIUrl":"10.1016/j.yrtph.2024.105713","url":null,"abstract":"<div><div>The escalating challenge of New Psychoactive Substances (NPS) necessitates enhanced global monitoring and analysis capabilities. This study introduces an advanced interactive visualization tool that employs Geographic Information System (GIS) technologies to improve the functionality of the UNODC's Early Warning Advisory. The tool enables dynamic observation and analysis of NPS's geographical and temporal distribution, thereby facilitating a comprehensive understanding of their public health impacts. By incorporating detailed choropleth maps and annual and cumulative bar charts, the tool allows policymakers and researchers to visually track and analyze trends in NPS usage and control efforts across different regions. The results demonstrate the tool's effectiveness in providing actionable insights, which support the strategic development of public health policies and interventions to curb the global rise in NPS usage. This initiative illustrates the essential role of digital tools in enhancing public health strategies and responses to emerging drug trends. This rising challenge underscores the urgent need for innovative solutions in monitoring drug trends, a theme explored in this paper. The web tool is available at <span><span>https://nps-vis.cmdm.tw</span><svg><path></path></svg></span>, and the code is available at <span><span>https://github.com/CMDM-Lab/nps-vis</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"153 ","pages":"Article 105713"},"PeriodicalIF":3.0,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142375878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1016/j.yrtph.2024.105709
Robert H. Heflich , Michelle E. Bishop , Roberta A. Mittelstaedt , Jian Yan , Sharon K. Guerrero , Audrey M. Sims , Kamela Mitchell , Nyosha Moore , Xilin Li , Nan Mei , Rosalie K. Elespuru , Sruthi T. King , David A. Keire , Naomi L. Kruhlak , Robert T. Dorsam , Andre S. Raw , Karen L. Davis Bruno , Timothy J. McGovern , Aisar H. Atrakchi
Accurately determining the mutagenicity of small-molecule N-nitrosamine drug impurities and nitrosamine drug substance-related impurities (NDSRIs) is critical to identifying mutagenic and cancer hazards. In the current study we have evaluated several approaches for enhancing assay sensitivity for evaluating the mutagenicity of N-nitrosamines in the bacterial reverse mutagenicity (Ames) test. Preincubation assays were conducted using five activation conditions: no exogenous metabolic activation and metabolic activation mixes employing both 10% and 30% liver S9 from hamsters and rats pretreated with inducers of enzymatic activity. In addition, preincubations were conducted for both 60 min and 30 min. These test variables were evaluated by testing 12 small-molecule N-nitrosamines and 17 NDSRIs for mutagenicity in Salmonella typhimurium tester strains TA98, TA100, TA1535, and TA1537, and Escherichia coli strain WP2 uvrA (pKM101). Eighteen of the 29 N-nitrosamine test substances tested positive under one or more of the testing conditions and all 18 positives could be detected by using tester strains TA1535 and WP2 uvrA (pKM101), preincubations of 30 min, and S9 mixes containing 30% hamster liver S9. In general, the conditions under which NDSRIs were mutagenic were similar to those found for small-molecule N-nitrosamines.
{"title":"Optimizing the detection of N-nitrosamine mutagenicity in the Ames test","authors":"Robert H. Heflich , Michelle E. Bishop , Roberta A. Mittelstaedt , Jian Yan , Sharon K. Guerrero , Audrey M. Sims , Kamela Mitchell , Nyosha Moore , Xilin Li , Nan Mei , Rosalie K. Elespuru , Sruthi T. King , David A. Keire , Naomi L. Kruhlak , Robert T. Dorsam , Andre S. Raw , Karen L. Davis Bruno , Timothy J. McGovern , Aisar H. Atrakchi","doi":"10.1016/j.yrtph.2024.105709","DOIUrl":"10.1016/j.yrtph.2024.105709","url":null,"abstract":"<div><div>Accurately determining the mutagenicity of small-molecule <em>N</em>-nitrosamine drug impurities and nitrosamine drug substance-related impurities (NDSRIs) is critical to identifying mutagenic and cancer hazards. In the current study we have evaluated several approaches for enhancing assay sensitivity for evaluating the mutagenicity of <em>N</em>-nitrosamines in the bacterial reverse mutagenicity (Ames) test. Preincubation assays were conducted using five activation conditions: no exogenous metabolic activation and metabolic activation mixes employing both 10% and 30% liver S9 from hamsters and rats pretreated with inducers of enzymatic activity. In addition, preincubations were conducted for both 60 min and 30 min. These test variables were evaluated by testing 12 small-molecule <em>N</em>-nitrosamines and 17 NDSRIs for mutagenicity in <em>Salmonella typhimurium</em> tester strains TA98, TA100, TA1535, and TA1537, and <em>Escherichia coli</em> strain WP2 uvrA (pKM101). Eighteen of the 29 <em>N</em>-nitrosamine test substances tested positive under one or more of the testing conditions and all 18 positives could be detected by using tester strains TA1535 and WP2 uvrA (pKM101), preincubations of 30 min, and S9 mixes containing 30% hamster liver S9. In general, the conditions under which NDSRIs were mutagenic were similar to those found for small-molecule <em>N</em>-nitrosamines.</div></div>","PeriodicalId":20852,"journal":{"name":"Regulatory Toxicology and Pharmacology","volume":"153 ","pages":"Article 105709"},"PeriodicalIF":3.0,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142352730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.yrtph.2024.105710
Payal Rana , Brett Hollingshead , Raja Mangipudy
The registration of biotherapeutics for chronic indications requires 6-month toxicity studies. However, extensive experience has shown that the non-clinical safety profiles of biotherapeutics are generally predictable. This suggests that conducting multiple studies, especially a 6-month study may not be necessary. In a meta-analysis of biologics developed for non-oncology indications over last 25 years at Pfizer, we compared organ system findings between short-term (1–3 month) and long-term (6-month) animal studies. Our goal was to determine if there were differences in the safety profiles between the two study durations and their relevance to human risk assessment. Our analysis revealed that most clinically relevant toxicities could be detected in shorter-term studies (87%; 26/30 programs). This suggests either an undifferentiated safety profile between short-and long-term studies, or anticipated toxicities based on the modality, such as immunogenicity or exaggerated pharmacology. However, for 4 out of 30 programs (13%), long-term studies did identify either potential new toxicities or more severe manifestation of exaggerated pharmacology, leading to modifications in clinical trial designs and human risk assessment. Our experience suggests that 3-month toxicity studies may be sufficient to support late-stage clinical development for a majority of standard biotherapeutic programs. This pragmatic and science-based approach aligns with the goal of advancing 3R's initiatives in nonclinical safety assessment.
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