Acceptance criteria for new approach methods in toxicology and human health-relevant life science research - part I.

Every test procedure, scientific and non-scientific, has inherent uncertainties, even when performed according to a standard operating procedure (SOP). In addition, it is prone to errors, defects, and mistakes introduced by operators, laboratory equipment, or materials used. Adherence to an SOP and comprehensive validation of the test method cannot guarantee that each test run produces data within the acceptable range of variability and with the precision and accuracy determined during the method validation. We illustrate here (part I) why controlling the validity of each test run is an important element of experimental design. The definition and application of acceptance criteria (AC) for the validity of test runs is important for the setup and use of test methods, particularly for the use of new approach methods (NAM) in toxicity testing. AC can be used for decision rules on how to handle data, e.g., to accept the data for further use (AC fulfilled) or to reject the data (AC not fulfilled). The adherence to AC has important requirements and consequences that may seem surprising at first sight: (i) AC depend on a test method's objectives, e.g., on the types/concentrations of chemicals tested, the regulatory context, the desired throughput; (ii) AC are applied and documented at each test run, while validation of a method (including the definition of AC) is only performed once; (iii) if AC are altered, then the set of data produced by a method can change. AC, if missing, are the blind spot of quality assurance: Test results may not be reliable and comparable. The establishment and uses of AC will be further detailed in part II of this series.

REACH out-numbered! The future of REACH and animal numbers.

The EU's REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) Regulation requires animal testing only as a last resort. However, our study (Knight et al., 2023) in this issue reveals that approximately 2.9 million animals have been used for REACH testing for reproductive toxicity, developmental toxicity, and repeated-dose toxicity alone as of December 2022. Currently, additional tests requiring about 1.3 million more animals are in the works. As compliance checks continue, more animal tests are anticipated. According to the European Chemicals Agency (ECHA), 75% of read-across methods have been rejected during compliance checks. Here, we estimate that 0.6 to 3.2 million animals have been used for other endpoints, likely at the lower end of this range. The ongoing discussion about the grouping of 4,500 regis-tered petrochemicals can still have a major impact on these numbers. The 2022 amendment of REACH is estimated to add 3.6 to 7.0 million animals. This information comes as the European Parliament is set to consider changes to REACH that could further increase animal testing. Two proposals currently under discussion would likely necessitate new animal testing: extending the requirement for a chemical safety assessment (CSA) to Annex VII substances could add 1.6 to 2.6 million animals, and the registration of polymers adds a challenge comparable to the petrochemical discussion. These findings high-light the importance of understanding the current state of REACH animal testing for the upcoming debate on REACH revisions as an opportunity to focus on reducing animal use.

4.2 million and counting The animal toll for REACH systemic toxicity studies.

The EU's chemicals regulation, REACH, requires that most chemicals in the EU be evaluated for human health and ecosystem risks, with a mandate to minimize use of animal tests for these evaluations. The REACH process has been ongoing since about 2008, but a calculation of the resulting animal use is not publicly available. For this reason, we have undertaken a count of animals used for REACH. With EU legislators set to consider REACH revisions that could expand animal testing, we are releasing results for test categories counted to date: reproductive toxicity tests, developmental toxicity tests, and repeat-ed-dose toxicity tests for human health. The total animal count as of December 2022 for these categories is about 2.9 million. Additional tests involving about 1.3 million animals are currently required by a final proposal authorization or compliance check but not yet completed. The total, 4.2 million, for just these three test categories exceeds the original European Com-mission forecast of 2.6 million for all REACH tests. The difference is primarily because the European Commission estimate excluded offspring, which are most of the animals used for REACH. Other reasons for the difference are extra animals included in tests to ensure sufficient survive to meet the minimum test requirement; dose range-finding tests; extra test animal groups, e.g., for recovery analysis; and a high rejection rate of read-across studies. Given higher than forecast animal use, the upcoming debate on proposed REACH revisions is an opportunity to refocus on reducing animal numbers in keeping with the REACH mandate.

The Current Status and Work of Three Rs Centres and Platforms in Europe.

The adoption of Directive 2010/63/EU on the protection of animals used for scientific purposes has given a major push to the formation of Three Rs initiatives in the form of centres and platforms. These centres and platforms are dedicated to the so-called Three Rs, which are the Replacement, Reduction and Refinement of animal use in experiments. ATLA's 50th Anniversary year has seen the publication of two articles on European Three Rs centres and platforms. The first of these was about the progressive rise in their numbers and about their founding history; this second part focuses on their current status and activities. This article takes a closer look at their financial and organisational structures, describes their Three Rs focus and core activities (dissemination, education, implementation, scientific quality/translatability, ethics), and presents their areas of responsibility and projects in detail. This overview of the work and diverse structures of the Three Rs centres and platforms is not only intended to bring them closer to the reader, but also to provide role models and show examples of how such Three Rs centres and platforms could be made sustainable. The Three Rs centres and platforms are very important focal points and play an immense role as facilitators of Directive 2010/63/EU 'on the ground' in their respective countries. They are also invaluable for the wide dissemination of information and for promoting the implementation of the Three Rs in general.

On the usefulness of animals as a model system (part I): Overview of criteria and focus on robustness.

Banning or reduction of the use of animals for laboratory experiments is a frequently-discussed societal and scientific issue. Moreover, the usefulness of animals needs to be considered in any decision process on the permission of specific animal studies. This complex issue is often simplified and generalized in the media around the question, "Are animals useful as a model?" To render an often emotional discussion about animal experimentation more rational, it is important to define "usefulness" in a structured and transparent way. To achieve such a goal, many sub-questions need to be asked, and the following aspects require clarification: (i) consistency of animal-derived data (robustness of the model system); (ii) scientific domain investigated (e.g., toxicology vs disease modelling vs therapy); (iii) measurement unit for "benefit" (inte-grating positive and negative aspects); (iv) benchmarking to alternatives; (v) definition of success criteria (how good is good enough); (vi) the procedure to assess benefit and necessity. This series of articles discusses the overall benchmarking process by specifying the six issues. The goal is to provide guidance on what needs to be clarified in scientific and political discussions. This framework should help in the future to structure available information, to identify and fill information gaps, and to arrive at rational decisions in various sub-fields of animal use. In part I of the series, we focus on the robustness of animal models. This describes the capacity of models to produce the same output/response when faced with the "same" input. Follow-up articles will cover the remaining usefulness aspects.

Continuing animal tests on cosmetic ingredients for REACH in the EU

EU cosmetic ingredients are governed by two regulations that conflict. Regulation EC 1223/2009, the Cosmetic Regulation, bans in vivo (animal) testing for cosmetic product safety assessments, including both final products and ingredients. At the same time, the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation can impose in vivo testing of those same ingredients under its chemical testing requirements. Here, we examined REACH dossiers for chemicals for which the only reported use is cosmetics to determine the extent of new in vivo testing caused by REACH. We found the REACH database has 3,206 chemical dossiers with cosmetics as a reported use. Of these, 419 report cosmetics as the only use, and 63 of these have in vivo tests completed after the Cosmetic Regulation ban on in vivo testing. Registrants largely used alternative, non-animal methods to evaluate ingredients for REACH, but some still conducted new in vivo tests to comply with REACH requirements for toxicity data and worker safety assessments. In some cases, ECHA, the agency that evaluates REACH dossiers, rejected registrants' alternative methods as insufficient and required new in vivo tests. As ECHA continues to evaluate dossiers, more requests for in vivo tests are likely. REACH tests on cosmetic ingredients appear only as "industrial chemicals legislation" tests in EU reports. Given the importance to consumers and the cosmetic industry of having cosmetics free of animal testing, the public should be made aware of REACH testing until the conflict between the regulations is resolved.

NAM-supported read-across: From case studies to regulatory guidance in safety assessment.

The use of new approach methodologies (NAMs) in support of read-across (RAx) approaches for regulatory purposes is a main goal of the EU-ToxRisk project. To bring this forward, EU-ToxRisk partners convened a workshop in close collaboration with regulatory representatives from key organizations including European regulatory agencies, such as the European Chemicals Agency (ECHA) and the European Food Safety Authority (EFSA), as well as the Scientific Committee on Consumer Safety (SCCS), national agencies from several European countries, Japan, Canada and the USA, as well as the Organisation for Economic Cooperation and Development (OECD). More than a hundred people actively participated in the discussions, bringing together diverse viewpoints across academia, regulators and industry. The discussion was organized starting from five practical cases of RAx applied to specific problems that offered the oppor-tunity to consider real examples. There was general consensus that NAMs can improve confidence in RAx, in particular in defining category boundaries as well as characterizing the similarities/dissimilarities between source and target substances. In addition to describing dynamics, NAMs can be helpful in terms of kinetics and metabolism that may play an important role in the demonstration of similarity or dissimilarity among the members of a category. NAMs were also noted as effective in providing quanti-tative data correlated with traditional no observed adverse effect levels (NOAELs) used in risk assessment, while reducing the uncertainty on the final conclusion. An interesting point of view was the advice on calibrating the number of new tests that should be carefully selected, avoiding the allure of "the more, the better". Unfortunately, yet unsurprisingly, there was no single approach befitting every case, requiring careful analysis delineating the optimal approach. Expert analysis and assessment of each specific case is still an important step in the process.

The EU-ToxRisk method documentation, data processing and chemical testing pipeline for the regulatory use of new approach methods.

Hazard assessment, based on new approach methods (NAM), requires the use of batteries of assays, where individual tests may be contributed by different laboratories. A unified strategy for such collaborative testing is presented. It details all procedures required to allow test information to be usable for integrated hazard assessment, strategic project decisions and/or for regulatory purposes. The EU-ToxRisk project developed a strategy to provide regulatorily valid data, and exemplified this using a panel of > 20 assays (with > 50 individual endpoints), each exposed to 19 well-known test compounds (e.g. rotenone, colchicine, mercury, paracetamol, rifampicine, paraquat, taxol). Examples of strategy implementation are provided for all aspects required to ensure data validity: (i) documentation of test methods in a publicly accessible database; (ii) deposition of standard operating procedures (SOP) at the European Union DB-ALM repository; (iii) test readiness scoring accoding to defined criteria; (iv) disclosure of the pipeline for data processing; (v) link of uncertainty measures and metadata to the data; (vi) definition of test chemicals, their handling and their behavior in test media; (vii) specification of the test purpose and overall evaluation plans. Moreover, data generation was exemplified by providing results from 25 reporter assays. A complete evaluation of the entire test battery will be described elsewhere. A major learning from the retrospective analysis of this large testing project was the need for thorough definitions of the above strategy aspects, ideally in form of a study pre-registration, to allow adequate interpretation of the data and to ensure overall scientific/toxicological validity.

Comparison between Communicated and Calculated Exposure Estimates Obtained through Three Modeling Tools.

This study aims to evaluate the risk assessment approach of the REACH legislation in industrial chemical departments with a focus on the use of three models to calculate exposures, and discuss those factors that can determine a bias between the estimated exposure (and therefore the expected risk) in the extended safety data sheets (e-SDS) and the expected exposure for the actual scenario. To purse this goal, the exposure estimates and risk characterization ratios (RCRs) of registered exposure scenarios (ES; "communicated exposure" and "communicated RCR") were compared with the exposure estimates and the corresponding RCRs calculated for the actual, observed ES, using recommended tools for the evaluation of exposure assessment and in particular the following tools: (i) the European Centre for Ecotoxicology and Toxicology of Chemicals Targeted Risk Assessment v.3.1 (ECETOC TRA), (ii) STOFFENMANAGER® v.8.0 and (iii) the Advanced REACH Tool (ART). We evaluated 49 scenarios in three companies handling chemicals. Risk characterization ratios (RCRs) were calculated by dividing estimated exposures by derived no-effect levels (DNELs). Although the calculated exposure and RCRs generally were lower than communicated, the correlation between communicated and calculated exposures and RCRs was generally poor, indicating that the generic registered scenarios do not reflect actual working, exposure and risk conditions. Further, some observed scenarios resulted in calculated exposure values and RCR higher than those communicated through chemicals' e-SDSs; thus 'false safe' scenarios (calculated RCRs > 1) were also observed. Overall, the obtained evidences contribute to doubt about whether the risk assessment should be performed using generic (communicated by suppliers) ES with insufficient detail of the specific scenario at all companies. Contrariwise, evidences suggested that it would be safer for downstream users to perform scenario-specific evaluations, by means of proper scaling approach, to achieve more representative estimates of chemical risk.

Harnessing the power of novel animal-free test methods for the development of COVID-19 drugs and vaccines.

The COVID-19-inducing virus, SARS-CoV2, is likely to remain a threat to human health unless efficient drugs or vaccines become available. Given the extent of the current pandemic (people in over one hundred countries infected) and its disastrous effect on world economy (associated with limitations of human rights), speedy drug discovery is critical. In this situation, past investments into the development of new (animal-free) approach methods (NAM) for drug safety, efficacy, and quality evaluation can be leveraged. For this, we provide an overview of repurposing ideas to shortcut drug development times. Animal-based testing would be too lengthy, and it largely fails, when a pathogen is species-specific or if the desired drug is based on specific features of human biology. Fortunately, industry has already largely shifted to NAM, and some public funding programs have advanced the development of animal-free technologies. For instance, NAM can predict genotoxicity (a major aspect of carcinogenicity) within days, human antibodies targeting virus epitopes can be generated in molecular biology laboratories within weeks, and various human cell-based organoids are available to test virus infectivity and the biological processes controlling them. The European Medicines Agency (EMA) has formed an expert group to pave the way for the use of such approaches for accelerated drug development. This situation illustrates the importance of diversification in drug discovery strategies and clearly shows the shortcomings of an approach that invests 95% of resources into a single technology (animal experimentation) in the face of challenges that require alternative approaches.

Internationalization of read-across as a validated new approach method (NAM) for regulatory toxicology.

Read-across (RAx) translates available information from well-characterized chemicals to a substance for which there is a toxicological data gap. The OECD is working on case studies to probe general applicability of RAx, and several regulations (e.g., EU-REACH) already allow this procedure to be used to waive new in vivo tests. The decision to prepare a review on the state of the art of RAx as a tool for risk assessment for regulatory purposes was taken during a workshop with international experts in Ranco, Italy in July 2018. Three major issues were identified that need optimization to allow a higher regulatory acceptance rate of the RAx procedure: (i) the definition of similarity of source and target, (ii) the translation of biological/toxicological activity of source to target in the RAx procedure, and (iii) how to deal with issues of ADME that may differ between source and target. The use of new approach methodologies (NAM) was discussed as one of the most important innovations to improve the acceptability of RAx. At present, NAM data may be used to confirm chemical and toxicological similarity. In the future, the use of NAM may be broadened to fully characterize the hazard and toxicokinetic properties of RAx compounds. Concerning available guidance, documents on Good Read-Across Practice (GRAP) and on best practices to perform and evaluate the RAx process were identified. Here, in particular, the RAx guidance, being worked out by the European Commission's H2020 project EU-ToxRisk together with many external partners with regulatory experience, is given.

New European Union statistics on laboratory animal use - what really counts!

Seven years after the last release, the European Commission has again collated and released data on laboratory animal use. The new report is the first to correspond to the requirements of the new Directive 2010/63/EU. Beside minor problems in reporting, the new reporting format is a major step forward, with additional new categories like severity allowing insight into animal use related questions that goes far beyond the previous reports. An in-depth analysis confirms a slight decrease in animal use from 2015 to 2017, but also compared to the 2005, 2008 and 2011 reports, though the new reporting scheme makes this comparison difficult. Notable success is evident for replacing rabbit pyrogen testing but, in general, the implementation of accepted alternative methods lags behind expec-tations. Beside the roughly 10 million animals per year covered in the report, about 8 million animals were identified that fall under the Directive but are not included in this number. Their omission downplays the impact of REACH on animal use. The report, second to none in its detail internationally, represents an important instrument for benchmarking and strategi-cally focusing activities in the 3Rs.

Erratum to Template for the description of cell-based toxicological test methods to allow evaluation and regulatory use of the data.

In this manuscript, which appeared in ALTEX (2019), 36(4), 682- 699, doi:10.14573/altex.1909271 , the affiliation of Hennicke Kamp should be Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany. Further, the reference to an article by Bal-Price et al. (2015) should have the following doi:10.1007/s00204-015-1464-2 .

Template for the description of cell-based toxicological test methods to allow evaluation and regulatory use of the data.

Only few cell-based test methods are described by Organisation for Economic Co-operation and Development (OECD) test guidelines or other regulatory references (e.g., the European Pharmacopoeia). The majority of toxicity tests still falls into the category of non-guideline methods. Data from these tests may nevertheless be used to support regulatory decisions or to guide strategies to assess compounds (e.g., drugs, agrochemicals) during research and development if they fulfill basic requirements concerning their relevance, reproducibility and predictivity. Only a method description of sufficient clarity and detail allows interpretation and use of the data. To guide regulators faced with increasing amounts of data from non-guideline studies, the OECD formulated Guidance Document 211 (GD211) on method documentation for the purpose of safety assessment. As GD211 is targeted mainly at regulators, it leaves scientists less familiar with regulation uncertain as to what level of detail is required and how individual questions should be answered. Moreover, little attention was given to the description of the test system (i.e., cell culture) and the steps leading to it being established in the guidance. To address these issues, an annotated toxicity test method template (ToxTemp) was developed (i) to fulfill all requirements of GD211, (ii) to guide the user concerning the types of answers and detail of information required, (iii) to include acceptance criteria for test elements, and (iv) to define the cells sufficiently and transparently. The fully annotated ToxTemp is provided here, together with reference to a database containing exemplary descriptions of more than 20 cell-based tests.

Optimizing drug discovery by Investigative Toxicology: Current and future trends.

Investigative Toxicology describes the de-risking and mechanistic elucidation of toxicities, supporting early safety decisions in the pharmaceutical industry. Recently, Investigative Toxicology has contributed to a shift in pharmaceutical toxicology, from a descriptive to an evidence-based, mechanistic discipline. This was triggered by high costs and low throughput of Good Laboratory Practice in vivo studies, and increasing demands for adhering to the 3R (Replacement, Reduction and Refinement) principles of animal welfare. Outside the boundaries of regulatory toxicology, Investigative Toxicology has the flexibility to embrace new technologies, enhancing translational steps from in silico, in vitro to in vivo mechanistic understanding to eventually predict human response. One major goal of Investigative Toxicology is improving preclinical decisions, which coincides with the concept of animal-free safety testing. Currently, compounds under preclinical development are being discarded due to the use of inappropriate animal models. Progress in Investigative Toxicology could lead to humanized in vitro test systems and the development of medicines less reliant on animal tests. To advance this field a group of 14 European-based leaders from the pharmaceutical industry founded the Investigative Toxicology Leaders Forum (ITLF), an open, non-exclusive and pre-competitive group that shares knowledge and experience. The ITLF collaborated with the Centre for Alternatives to Animal Testing Europe (CAAT-Europe) to organize an "Investigative Toxicology Think-Tank", which aimed to enhance the interaction with experts from academia and regulatory bodies in the field. Summarizing the topics and discussion of the workshop, this article highlights Investigative Toxicology's position by identifying key challenges and perspectives.

Animal testing and its alternatives - the most important omics is economics.

For a long time, the discussion about animal testing vs its alternatives centered on animal welfare. This was a static warfare, or at least a gridlock, where life scientists had to take a position and make their value choices and hardly anyone changed sides. Technical advances have changed the frontline somewhat, with in vitro and in silico methods gaining more ground. Only more recently has the economic view begun to have an impact: Many animal tests are simply too costly, take too long, and give misleading results. As an extension and update to previous articles in this series written a decade ago, we reanalyze the economic landscape of especially regulatory use of animal testing and this time also consider respective alternative tests. Despite some ambiguity and data gaps, which we have filled with crude estimates, a picture emerges of globally regulated industries that are subject to stark geographic and sectorial differences in regulation, which determine their corresponding animal use. Both animal testing and its alternatives are industries in their own right, offering remarkable business opportunities for biotech and IT companies as well as contract research organizations. In light of recent revelations as to the reproducibility and relevance issues of many animal tests, the economic consequences of incorrect results and the reasons for still maintaining often outdated animal test approaches are discussed.