Altex-Alternatives To Animal Experimentation最新文献

Virtual control groups (VCGs) created from historical control data (HCD) can reduce the number of concurrent control group animals needed in regulatory toxicity studies by up to 25%. This study investigates the performance of VCGs on statistical outcomes of body weight development between treatment and control groups in legacy studies. The objective is to reproduce the statistical outcomes of 28-day sub-chronic studies (legacy studies) after replacing the concurrent control group with virtual ones. In rodent toxicity studies initial body weight is used as surrogate for the age of animals. For the assessment of VCG-sampling methods, three different approaches were explored: (i) sam­pling VCGs from the entire HCD, ignoring initial body weight information of the legacy study, (ii) sampling from HCD by matching the legacy study’s initial body weights, and (iii) sampling from HCD with assigned statistical weights derived from legacy study initial body weight information. The ability to reproduce statistical outcomes using virtual controls was determined by the congruence between the legacy study and the HCD weight distribution: regardless of the chosen approach, the ability to reproduce statistical outcomes was high for VCGs when the legacy study’s initial body weight distribution was similar to the HCD’s. When the initial body weight range of the legacy study was at the extreme ends of the HCD’s distribution, the weighted sampling approach was superior. This article demonstrates the importance of proper HCD matching by the legacy study’s initial body weight and discusses conditions to accurately reproduce body weight development.

Historical data from control groups in animal toxicity studies are currently mainly used for comparative purposes to assess validity and robustness of study results. Due to the highly controlled environment in which the studies are performed and the homogeneity of the animal collectives it has been proposed to use the historical data to build so-called virtual control groups, which could partly or entirely replace the concurrent control group. This would constitute a substantial contribution to the reduction of animal use in safety studies. Before the concept can be implemented, the prerequisites regarding data collection, curation, and statistical evaluation together with a validation strategy need to be identified to avoid any impairment of the study outcome and subsequent consequences for human risk assessment. To further assess and develop the concept of virtual control groups, the transatlantic think tank for toxicology (t4) sponsored a workshop with stakeholders from the phar­maceutical and chemical industry, academia, FDA, contract research organizations (CROs), and non-governmental organizations in Washington, which took place in March 2023. This report sum­marizes the current efforts of a European initiative to share, collect, and curate animal control data in a centralized database and the first approaches to identify optimal matching criteria between virtual controls and the treatment arms of a study as well as first reflections about strategies for a qualifi­cation procedure and potential pitfalls of the concept.

Following a review of Directive 2010/63/EU on the protection of animals used for scientific pur­poses in the European Union (EU), non-technical project summaries (NTS) of all approved projects must be published in a central database using a standard template. Our initial review of the NTS reported in ALTEX in 2018 had found the NTS to be deficient in their accessibility and quality, notably the “adverse effects” section where the harms to the animals are meant to be described. Here we repeat our review to see if these legislative changes have improved the accessibility and quality of the NTS. As before, we focused on the NTS from the United Kingdom (UK) and Germany; even though the UK has left the EU, it is using the same template. We found significant improvement in the reporting of five of the six elements we identified as essential to the “predicted harms” section. However, there was no significant improvement in the reporting of adverse effects. Only 41% of German NTS and 48% of UK NTS are fully reporting this important element of the “predicted harms” section. In our view, researchers need support in describing the impact of their research on the animals and to assist here we include a checklist for competent authorities and a list of suggested terminology for standard administration and sampling procedures. Unless the NTS improve further, their utility as a tool for sharing of good practices in the 3Rs or to support evidence-based policy­making will remain limited.

Validation establishes the reproducibility and relevance of regulatory test methods, particularly for new approach methods (NAMs) as alternatives to animal testing. While validation concepts provide a framework to assess method suitability, they rarely undergo method-critical assessment. This paper explores the philosophical and ethical foundations of the validation process, drawing from various philosophical traditions and contemporary ethical frameworks. How validation intersects with utilitarian principles, ethics of responsibility, and post-modern critiques is examined, offering a multifaceted perspective on its role in scientific progress and societal values. The paper argues for a paradigm shift in validation, moving beyond traditional animal-based comparisons towards more flexible, fit-for-purpose approaches that embrace emerging technologies and ethical con-siderations. Key ethical principles guiding NAM validation are discussed, including beneficence, non-maleficence, justice, and respect for animal welfare. Integrating these principles with scientific rigor can create a more holistic validation framework that balances human safety, animal welfare, and technological innovation. By critically examining the philosophical underpinnings of validation, this paper aims to stimulate dialogue on reforming the process to better align with contemporary scientific knowledge, ethical standards, and societal expectations. It calls for a more adaptive, transparent, and ethically grounded approach to validation that can accelerate the adoption of innovative and human-relevant toxicological methods while maintaining scientific integrity and public trust.

Dysregulation of vascular endothelial growth factor (VEGF) and its receptor (VEGFR) contributes to atherosclerosis and cardiovascular disease (CVD), making it a potential target for CVD risk assessment. High-throughput screening (HTS) approaches have resulted in large-scale in vitro data, providing mechanistic information that can help assess chemical toxicity and identify molecular ini­tiating events (MIEs) of adverse outcome pathways (AOPs). AOPs represent a logical sequence of biological responses contributing to toxicity and are valuable tools to inform chemical risk assessment. Here, we used HTS data to formulate an AOP relating VEGF signaling perturbation to atheroscle­rosis. ToxCast, Tox21, and PubChem data were evaluated to obtain bioprofiles of 4165 compounds active in assays targeting VEGFR. Cheminformatics analysis identified 109 enriched structural fin­gerprints. Applying a subspace clustering approach based on chemical structure bioactivity yielded 12 primary targets, whose relevance to CVD was confirmed by an AI-assisted literature review. An AOP was hypothesized by coupling mechanistic relationships highlighted by HTS data with literature review findings, linking serotonin receptor (HTR), estrogen receptor alpha (ERα), and vasopressin receptor (AVPR) targets with VEGFR activity, angiogenic signaling, and atherosclerosis. Several endocrine disrupting chemicals (EDCs), e.g., bisphenols, triclosan, dichlorodiphenyltrichloroethane (DDT), and polychlorinated biphenyls (PCBs), were identified as relevant chemical stressors. Sub­space clustering of these chemicals evaluated potential MIEs and highlighted associations with use case classes. By applying computational methods to profile HTS data and hypothesize a mechanistic AOP, this study proposes a data-driven approach to evaluating environmental cardiotoxicity, which could eventually supplement and reduce the need for animal testing in toxicological assessments.

The webinar series and workshop titled “Trust Your Gut: Establishing Confidence in Gastrointestinal Models – An Overview of the State of the Science and Contexts of Use” was co-organized by NICEATM, NIEHS, FDA, EPA, CPSC, DoD, and the Johns Hopkins Center for Alternatives to Animal Testing (CAAT) and hosted at the National Institutes of Health in Bethesda, MD, USA on October 11-12, 2023. New approach methods (NAMs) for assessing issues of gastrointestinal tract (GIT)- related toxicity offer promise in addressing some of the limitations associated with animal-based assessments. GIT NAMs vary in complexity, from two-dimensional monolayer cell line-based systems to sophisticated 3-dimensional organoid systems derived from human primary cells. Despite advances in GIT NAMs, challenges remain in fully replicating the complex interactions and pro­cesses occurring within the human GIT. Presentations and discussions addressed regulatory needs, challenges, and innovations in incorporating NAMs into risk assessment frameworks; explored the state of the science in using NAMs for evaluating systemic toxicity, understanding absorption and pharmacokinetics, evaluating GIT toxicity, and assessing potential allergenicity; and discussed strengths, limitations, and data gaps of GIT NAMs as well as steps needed to establish confidence in these models for use in the regulatory setting.

Hazard assessment requires toxicity tests to allow deriving protective points of departure (PoDs) for risk assessment irrespective of a compound’s mode of action (MoA). The scope of in vitro test batteries (ivTB) needed to assess systemic toxicity is still unclear. We explored the protectiveness regarding systemic toxicity of an ivTB with a scope that was guided by previous findings from rodent studies, where examining six main targets, including liver and kidney, was sufficient to predict the guideline scope-based PoD with high probability. The ivTB comprises human in vitro models representing liver, kidney, lung, and the neuronal system covering transcriptome, mitochondrial dysfunction, and neuronal outgrowth. Additionally, 32 CALUXR- and 10 HepG2 BAC-GFP reporters cover a broad range of disturbance mechanisms. Eight compounds were chosen for causing adverse effects such as immunotoxicity or anemia in vivo, i.e., effects not directly covered by assays in the ivTB. PoDs derived from the ivTB and from oral repeated dose studies in rodents were extrapolated to maximum unbound plasma concentrations for comparison. The ivTB-based PoDs were one to five orders of magnitude lower than in vivo PoDs for six of eight compounds, implying that they were protective. The extent of in vitro response varied across test compounds. Especially for hematotoxic substances, the ivTB showed either no response or only cytotoxicity. Assays better capturing this type of hazard would be needed to complement the ivTB. This study highlights the potentially broad applicability of ivTBs for deriving protective PoDs of compounds with unknown MoA.