International Harmonization and Cooperation in the Validation of Alternative Methods.

The development and validation of scientific alternatives to animal testing is important not only from an ethical perspective (implementation of 3Rs), but also to improve safety assessment decision making with the use of mechanistic information of higher relevance to humans. To be effective in these efforts, it is however imperative that validation centres, industry, regulatory bodies, academia and other interested parties ensure a strong international cooperation, cross-sector collaboration and intense communication in the design, execution, and peer review of validation studies. Such an approach is critical to achieve harmonized and more transparent approaches to method validation, peer-review and recommendation, which will ultimately expedite the international acceptance of valid alternative methods or strategies by regulatory authorities and their implementation and use by stakeholders. It also allows achieving greater efficiency and effectiveness by avoiding duplication of effort and leveraging limited resources. In view of achieving these goals, the International Cooperation on Alternative Test Methods (ICATM) was established in 2009 by validation centres from Europe, USA, Canada and Japan. ICATM was later joined by Korea in 2011 and currently also counts with Brazil and China as observers. This chapter describes the existing differences across world regions and major efforts carried out for achieving consistent international cooperation and harmonization in the validation and adoption of alternative approaches to animal testing.

ECVAM and new technologies for toxicity testing.

The development of alternative empirical (testing) and non-empirical (non-testing) methods to traditional toxicological tests for complex human health effects is a tremendous task. Toxicants may potentially interfere with a vast number of physiological mechanisms thereby causing disturbances on various levels of complexity of human physiology. Only a limited number of mechanisms relevant for toxicity ('pathways' of toxicity) have been identified with certainty so far and, presumably, many more mechanisms by which toxicants cause adverse effects remain to be identified. Recapitulating in empirical model systems (i.e., in vitro test systems) all those relevant physiological mechanisms prone to be disturbed by toxicants and relevant for causing the toxicity effect in question poses an enormous challenge. First, the mechanism(s) of action of toxicants in relation to the most relevant adverse effects of a specific human health endpoint need to be identified. Subsequently, these mechanisms need to be modeled in reductionist test systems that allow assessing whether an unknown substance may operate via a specific (array of) mechanism(s). Ideally, such test systems should be relevant for the species of interest, i.e., based on human cells or modeling mechanisms present in humans. Since much of our understanding about toxicity mechanisms is based on studies using animal model systems (i.e., experimental animals or animal-derived cells), designing test systems that model mechanisms relevant for the human situation may be limited by the lack of relevant information from basic research. New technologies from molecular biology and cell biology, as well as progress in tissue engineering, imaging techniques and automated testing platforms hold the promise to alleviate some of the traditional difficulties associated with improving toxicity testing for complex endpoints. Such new technologies are expected (1) to accelerate the identification of toxicity pathways with human relevance that need to be modeled in test methods for toxicity testing (2) to enable the reconstruction of reductionist test systems modeling at a reduced level of complexity the target system/organ of interest (e.g., through tissue engineering, use of human-derived cell lines and stem cells etc.), (3) to allow the measurement of specific mechanisms relevant for a given health endpoint in such test methods (e.g., through gene and protein expression, changes in metabolites, receptor activation, changes in neural activity etc.), (4) to allow to measure toxicity mechanisms at higher throughput rates through the use of automated testing. In this chapter, we discuss the potential impact of new technologies on the development, optimization and use of empirical testing methods, grouped according to important toxicological endpoints. We highlight, from an ECVAM perspective, the areas of topical toxicity, skin absorption, reproductive and developmental toxicity, carcinogenicity/genotoxicity, sensitization, hematopoeisis and toxicokinetics and discuss strategic developments including ECVAM's database service on alternative methods. Neither the areas of toxicity discussed nor the highlighted new technologies represent comprehensive listings which would be an impossible endeavor in the context of a book chapter. However, we feel that these areas are of utmost importance and we predict that new technologies are likely to contribute significantly to test development in these fields. We summarize which new technologies are expected to contribute to the development of new alternative testing methods over the next few years and point out current and planned ECVAM projects for each of these areas.

Analytical frameworks in colorectal cancer guidelines: development of methods for systematic reviews, their application and practical guidance for their use.

OBJECTIVES: Analytical frameworks are graphical representation of the key questions answered by a systematic review and can support the development of guideline recommendations. Our objectives were to a) conduct a systematic review to identify, describe and compare all analytical frameworks published as part of a systematic and guideline development process related to colorectal cancer (CRC), and b) to use this case study to develop guidance on how to conduct systematic reviews of analytical frameworks. METHODS: We developed a search strategy to identify eligible studies in Medline and Embase from 1996 until December 2020. We also manually searched guideline databases and websites to identify all guidelines and systematic reviews in CRC that used an analytical framework. We assessed the quality of the guidelines using the Appraisal of Guidelines for Research and Evaluation II tool. The systematic review was registered in International Prospective Register of Systematic Reviews, registration CRD42020172117. RESULTS: We screened 34,505 records and identified 1,166 guidelines and 3,127 systematic reviews on CRC of which five met our inclusion criteria. These five publications included four analytical frameworks in colorectal cancer (one update). We also describe our methodological approach to systematic reviews for analytical frameworks and underlying concepts for developing analytical framework using a bottom-up or top-down approach. CONCLUSION: Few guidelines and systematic reviews are utilizing analytical frameworks in the development of recommendations. Development of analytical frameworks should begin with a systematic search for existing analytical frameworks and follow a structured conceptual approach for their development to support guideline recommendations. Our methods may be helpful in achieving these objectives.

The ECVAM Scientific Information Service (SIS).

The aim of this ECVAM Status Seminar was to critically review the contributions made by ECVAM in relation to its four main task. The establishment and maintenance of the ECVAM Scientific Information Service (SIS) is a precise means of fulfilling one of these four principal duties of ECVAM. The major achievements of the SIS, and the efforts required to achieve them, are discussed, together with the immediate future for the SIS.

The ECVAM Scientific Information Service (SIS).

This article provides a general view about the main Scientific Information Service (SIS) projects and their current status. The SIS was established in 1996, to best achieve one of the four main obligations of the European Centre for the Validation of Alternative Methods (ECVAM), as required by the European Commission and Parliament, to establish and maintain a database on alternative procedures to animal experimentation. Two projects have been carried out: the SIS databases providing factual information on various aspects of animal alternatives and the ECVAM Thesaurus. The first online version of selected SIS databases was published on the Internet in 2001. The ECVAM Thesaurus will be made available for practical applications in 2004, and the general website of the whole ECVAM unit has been available since autumn 2002.

A modular approach to the ECVAM principles on test validity.

The European Centre for the Validation of Alternative Methods (ECVAM) proposes to make the validation process more flexible, while maintaining its high standards. The various aspects of validation are broken down into independent modules, and the information necessary to complete each module is defined. The data required to assess test validity in an independent peer review, not the process, are thus emphasised. Once the information to satisfy all the modules is complete, the test can enter the peer-review process. In this way, the between-laboratory variability and predictive capacity of a test can be assessed independently. Thinking in terms of validity principles will broaden the applicability of the validation process to a variety of tests and procedures, including the generation of new tests, new technologies (for example, genomics, proteomics), computer-based models (for example, quantitative structure-activity relationship models), and expert systems. This proposal also aims to take into account existing information, defining this as retrospective validation, in contrast to a prospective validation study, which has been the predominant approach to date. This will permit the assessment of test validity by completing the missing information via the relevant validation procedure: prospective validation, retrospective validation, catch-up validation, or a combination of these procedures.

ECVAM's response to the changing political environment for alternatives: consequences of the European Union chemicals and cosmetics policies.

The European Centre for the Validation of Alternative Methods (ECVAM) has restructured its services by directly targeting the animal tests that need to be replaced. In view of the short time-lines for making available and implementing validated methods, ECVAM is offering to steer the process by bringing together the inputs of stakeholders and encouraging the early involvement of regulators. In essence, steering groups formed by ECVAM senior staff, and complemented with external experts, will carry out the project management and will coordinate the various inputs.

Report and recommendations of the international workshop "Retrieval approaches for information on alternative methods to animal experiments".

In the member states of the EU and in the USA, scientists are obliged by animal welfare legislation not to conduct an animal experiment if another scientifically satisfactory method is reasonably and practicably available. To meet the regulatory obligation to use alternatives to animal experiments, scientists should consult literature and other relevant sources on alternatives prior to any experimental study on laboratory animals. It is the responsibility of the individual scientist to select the most appropriate database to obtain information on alternatives, which have been defined as methods that refine, reduce or replace animal experiments (the 3 Rs concept of Russell and Burch (1959)). Specialised information services provide support to scientists searching for publications on alternative methods. On occasion of a workshop in Berlin in November 2003, representatives of animal welfare information centres discussed currently available information sources on alternative methods, index terms for alternative methods, and search strategies based on index terms for alternative methods. ZEBET presented an investigation on the current status of indexing systems on alternative methods in established literature databases. The project analysed how the results of a search for publications on alternatives was influenced by the indexing procedure. The results of the study were exemplified by a typical search result. The results of the study indicated that the current indexing systems do not provide the required information, since not all of the relevant information is indexed under "alternative methods". The workshop participants developed recommendations for ad hoc working groups and research projects, e.g. development of suitable search strategies on alternative methods for scientists.