Transitioning biomedical research toward human-centric methodologies: systems-based strategies

Human-centric methodologies like microphysiological systems and in silico methods have shown promise in addressing the limitations of animal models in understanding human biology and responding to public health priorities. However, the prevailing paradigm based on animal research persists. The article proposes a systemic thinking approach, endorsed by the OECD and the EU, as a tool to leverage innovation to reframe the issue and achieve transformative policies. By identifying the complex factors shaping method selection in basic and biomedical research, a simplified model is presented to illuminate the systemic nature of this decision-making process. The goal is not to prescribe solutions but to offer policymakers a new framework for more-effective strategies, emphasizing collaboration among stakeholders and the need for robust data.

Examining animal testing for risk assessment: A WC-12 workshop report

In toxicology and regulatory testing, the use of animal methods has been both a cornerstone and a subject of intense debate. To continue this discourse a panel and audience representing scientists from various sectors and countries convened at a workshop held during the 12th World Congress on Alternatives and Animal Use in the Life Sciences (WC-12). The ensuing discussion focused on the scientific and ethical considerations surrounding the necessity and responsibility of defending the creation of new animal data in regulatory testing. The primary aim was to foster an open dialogue between the panel members and the audience while encouraging diverse perspectives on the responsibilities and obligations of various stakeholders (including industry, regulatory bodies, technology developers, research scientists, and animal welfare NGOs) in defending the development and subsequent utilization of new animal data. This workshop summary report captures the key elements from this critical dialogue and collective introspection. It describes the intersection of scientific progress and ethical responsibility as all sectors seek to accelerate the pace of 21st century predictive toxicology and new approach methodologies (NAMs) for the protection of human health and the environment.

Patient-Derived Xenograft vs. Organoids: A Preliminary Analysis of Cancer Research Output, Funding and Human Health Impact in 2014-2019

Cancer remains a major threat to mortality and morbidity globally, despite intense research and generous funding. Patient-derived xenograft (PDX) models-where tumor biopsies are injected into an animal-were developed to improve the predictive capacity of preclinical animal models. However, recent observations have called into question the clinical relevance, and therefore the translational accuracy, of these. Patient-derived organoids (PDO) use patient tumor samples to create in vitro models that maintain aspects of tumor structure and heterogeneity. We undertook a preliminary analysis of the number of breast, colorectal, and lung cancer research studies using PDX or PDO published worldwide between 2014-2019. We looked for evidence of impacts of this research on human health. The number of publications that focused on PDO is gradually increasing over time, but is still very low compared to publications using PDX models. Support for new research projects using PDO is gradually increasing, a promising indicator of a shift towards more human-relevant approaches to understanding human disease. Overall, increases in total funding for these three major cancer types does not appear to be translating to any consequential increase in outputs, defined for this purpose as publications associated with clinical trials. With increasing public discomfort in research using animals and demands for 'alternative' methods, it is timely to consider how to implement non-animal methods more effectively.

Global harmonization of vaccine testing requirements: Making elimination of the ATT and TABST a concrete global achievement

This one-day symposium organized by Humane Society International (HSI) brought together 18 international experts from Argentina, Brazil, China, Europe, India, Russia, South Africa and the United States to discuss the elimination of the abnormal toxicity test (ATT) from the testing requirements for human vaccines as well as the target animal batch safety test (TABST) and the laboratory animal batch safety test (LABST) for veterinary vaccines. Participants reported on country-specific regulatory requirements and, where present, the perspectives on waiver and elimination of those tests. In addition, the attendees, with HSI in the role of facilitator, moved to define the barriers to the complete elimination or waiving of these tests. This report expounds the outcomes of the symposium, and introduces a proposed roadmap - populated with country specific activities - for the elimination of these tests.

Workshop on the validation and regulatory acceptance of innovative 3R approaches in regulatory toxicology - Evolution versus revolution

At a joint workshop organized by RIVM and BfR, international experts from governmental institutes, regulatory agencies, industry, academia and animal welfare organizations discussed and provided recommendations for the development, validation and implementation of innovative 3R approaches in regulatory toxicology. In particular, an evolutionary improvement of our current approach of test method validation in the context of defined approaches or integrated testing strategies was discussed together with a revolutionary approach based on a comprehensive description of the physiological responses of the human body to chemical exposure and the subsequent definition of relevant and predictive in vitro, in chemico or in silico methods. A more comprehensive evaluation of biological relevance, scientific validity and regulatory purpose of new test methods and assessment strategies together with case studies that provide practical experience with new approaches were discussed as essential steps to build up the necessary confidence to facilitate regulatory acceptance.

Human-specific approaches to brain research for the 21st century: a South American perspective

The 21st century paradigm in toxicology, which emphasizes mechanistic understanding and species-relevant modeling of human biology and pathophysiology, is gaining traction in the wider biosciences through a global workshop series organized by the BioMed21 Collaboration. The second of this series, entitled Emerging Technology Toward Pathway-Based Human Brain Research, was held in Brazil in 2017, bringing together leading South American and international scientists, research funders and other stakeholders. The aims were to foster strategic scientific dialogue and identify actionable consensus recommendations as a first step toward a roadmap for 21st century, human-specific health research and funding in the region.

Mental Stress from Animal Experiments: a Survey with Korean Researchers

Animal experiments have been widely conducted in the life sciences for more than a century, and have long been a subject of ethical and societal controversy due to the deliberate infliction of harm upon sentient animals. However, the harmful use of animals may also negatively impact the mental health of researchers themselves. We sought to evaluate the anxiety level of researchers engaged in animal use to analyse the mental stress from animal testing. The State Anxiety Scale of the State-Trait Anxiety Inventory (STAI) was used to evaluate how researchers feel when they conduct animal, as opposed to non-animal, based experiments (95 non-animal and 98 animal testing researchers). The Trait Anxiety Scale of STAI was employed to measure proneness to anxiety, namely the base trait of the researchers. Additionally, the information on sex, age, education, income, and total working periods was collected. While the Trait Anxiety scores were comparable (41.5 ± 10.9 versus 42.9 ± 10.1, p = 0.3682, t-test), the State Anxiety scores were statistically significantly higher for animal users than non-animal users (45.1 ± 10.7 versus 41.3 ± 9.4, p = 0.011). This trend was consistent for both male and female. Notably, younger animal testers (≤ 30 years of age) with less work experience (≤ 2 years) and lower income level (≤ 27,000 USD) exhibited higher anxiety scores, whereas these factors did not affect the anxiety level of non-animal users. The present study demonstrated that participation in animal experiments can negatively impact the mental health of researchers.

Act on the Registration and Evaluation of Chemicals (K-REACH) and replacement, reduction or refinement best practices

OBJECTIVES

Korea's Act on the Registration and Evaluation of Chemicals (K-REACH) was enacted for the protection of human health and the environment in 2015. Considering that about 2000 new substances are introduced annually across the globe, the extent of animal testing requirement could be overwhelming unless regulators and companies work proactively to institute and enforce global best practices to replace, reduce or refine animal use. In this review, the way to reduce the animal use for K-REACH is discussed.

METHODS

Background of the enforcement of the K-REACH and its details was reviewed along with the papers and regulatory documents regarding the limitation of animal experiments and its alternatives in order to discuss the regulatory adoption of alternative tests.

RESULTS

Depending on the tonnage of the chemical used, the data required ranges from acute and other short-term studies for a single exposure route to testing via multiple exposure routes and costly, longer-term studies such as a full two-generation reproducibility toxicity. The European Registration, Evaluation, Authorization and Restriction of Chemicals regulation provides for mandatory sharing of vertebrate test data to avoid unnecessary duplication of animal use and test costs, and obligation to revise data requirements and test guidelines "as soon as possible" after relevant, validated replacement, reduction or refinement (3R) methods become available. Furthermore, the Organization for Economic Cooperation and Development actively accepts alternative animal tests and 3R to chemical toxicity tests.

CONCLUSIONS

Alternative tests which are more ethical and efficient than animal experiments should be widely used to assess the toxicity of chemicals for K-REACH registration. The relevant regulatory agencies will have to make efforts to actively adopt and uptake new alternative tests and 3R to K-REACH.

Lessons from Toxicology: Developing a 21st-Century Paradigm for Medical Research

Biomedical developments in the 21st century provide an unprecedented opportunity to gain a dynamic systems-level and human-specific understanding of the causes and pathophysiologies of disease. This understanding is a vital need, in view of continuing failures in health research, drug discovery, and clinical translation. The full potential of advanced approaches may not be achieved within a 20th-century conceptual framework dominated by animal models. Novel technologies are being integrated into environmental health research and are also applicable to disease research, but these advances need a new medical research and drug discovery paradigm to gain maximal benefits. We suggest a new conceptual framework that repurposes the 21st-century transition underway in toxicology. Human disease should be conceived as resulting from integrated extrinsic and intrinsic causes, with research focused on modern human-specific models to understand disease pathways at multiple biological levels that are analogous to adverse outcome pathways in toxicology. Systems biology tools should be used to integrate and interpret data about disease causation and pathophysiology. Such an approach promises progress in overcoming the current roadblocks to understanding human disease and successful drug discovery and translation. A discourse should begin now to identify and consider the many challenges and questions that need to be solved.

Humane Society International's global campaign to end animal testing

The Research & Toxicology Department of Humane Society International (HSI) operates a multifaceted and science-driven global programme aimed at ending the use of animals in toxicity testing and research. The key strategic objectives include: a) ending cosmetics animal testing worldwide, via the multinational Be Cruelty-Free campaign; b) achieving near-term reductions in animal testing requirements through revision of product sector regulations; and c) advancing humane science by exposing failing animal models of human disease and shifting science funding toward human biology-based research and testing tools fit for the 21st century. HSI was instrumental in ensuring the implementation of the March 2013 European sales ban for newly animal-tested cosmetics, in achieving the June 2013 cosmetics animal testing ban in India as well as major cosmetics regulatory policy shifts in China and South Korea, and in securing precedent-setting reductions in in vivo data requirements for pesticides in the EU through the revision of biocides and plant protection product regulations, among others. HSI is currently working to export these life-saving measures to more than a dozen industrial and emerging economies.

An evaluation of the US High Production Volume (HPV) chemical-testing programme: A study in (Ir)relevance, redundancy and retro thinking

Under the US Environmental Protection Agency (EPA) High Production Volume (HPV) Challenge Programme, chemical companies have volunteered to conduct screening-level toxicity tests on approximately 2800 widely-used industrial chemicals. Participating companies are committed to providing available toxicity information to the EPA and presenting testing proposals for review by the EPA and posting on the EPA Web site as public information. People for the Ethical Treatment of Animals (PETA) and a coalition of animal protection organisations have reviewed all the test plans submitted by the participating chemical companies for compliance with the original HPV framework, as well as with animal welfare guidelines issued by the EPA in October 1999. Our review found major and recurring flaws in the programme's execution, as well as in its fundamental design. Approximately 75% of the test plans reviewed violated fundamental terms of the programme. Many participating companies failed to conduct comprehensive analyses of available data and instead proposed superfluous and meaningless tests. The US HPV programme's exclusion of human health and exposure data has led to numerous examples of irrelevant experiments that will not affect how a chemical substance is used or handled. Contrary to claims by both the EPA and Environmental Defense that few new animal tests are being performed, an estimated 100,000 animals have already died in this US Government-sponsored animal-testing programme.

Can acute dermal systemic toxicity tests be replaced with oral tests? A comparison of route-specific systemic toxicity and hazard classifications under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)

Acute systemic toxicity data (LD50 values) and hazard classifications derived in the rat following oral administration and dermal application have been analysed to examine whether or not orally-derived hazard classification or LD50 values can be used to determine dermal hazard classification. Comparing the oral and dermal classifications for 335 substances derived from oral and dermal LD50 values respectively revealed 17% concordance, and indicated that 7% of substances would be classified less severely while 76% would be classified more severely if oral classifications were applied directly to the dermal route. In contrast, applying the oral LD50 values within the dermal classification criteria to determine the dermal classification reduced the concordance to 15% and the relative 'under-classification' to 1%, but increased the relative 'over-classification' to 84%. Both under- and over-classification are undesirable, and mitigation strategies are discussed. Finally, no substance with an oral LD50 of >2000mg/kg was classified for acute systemic toxicity by the dermal route, suggesting that dermal testing for acute systemic toxicity of such substances adds nothing to the hazard characterisation and should be removed from routine regulatory data requirements.

Cross-sector review of drivers and available 3Rs approaches for acute systemic toxicity testing

Acute systemic toxicity studies are carried out in many sectors in which synthetic chemicals are manufactured or used and are among the most criticized of all toxicology tests on both scientific and ethical grounds. A review of the drivers for acute toxicity testing within the pharmaceutical industry led to a paradigm shift whereby in vivo acute toxicity data are no longer routinely required in advance of human clinical trials. Based on this experience, the following review was undertaken to identify (1) regulatory and scientific drivers for acute toxicity testing in other industrial sectors, (2) activities aimed at replacing, reducing, or refining the use of animals, and (3) recommendations for future work in this area.

Bringing toxicology into the 21st century: a global call to action

Conventional toxicological testing methods are often decades old, costly and low-throughput, with questionable relevance to the human condition. Several of these factors have contributed to a backlog of chemicals that have been inadequately assessed for toxicity. Some authorities have responded to this challenge by implementing large-scale testing programmes. Others have concluded that a paradigm shift in toxicology is warranted. One such call came in 2007 from the United States National Research Council (NRC), which articulated a vision of "21st century toxicology" based predominantly on non-animal techniques. Potential advantages of such an approach include the capacity to examine a far greater number of chemicals and biological outcomes at more relevant exposure levels; a substantial reduction in testing costs, time and animal use; and the grounding of regulatory decisions on human rather than rodent biology. In order for the NRC's and similar proposals to make a significant impact on regulatory toxicology in the foreseeable future, they must be translated into sustained multidisciplinary research programmes that are well co-ordinated and funded on a multinational level. The Humane Society is calling for a "big biology" project to meet this challenge. We are in the process of forging an international, multi-stakeholder consortium dedicated to implementing the NRC vision.

The development of new concepts for assessing reproductive toxicity applicable to large scale toxicological programmes

Large scale toxicological testing programmes which are currently ongoing such as the new European chemical legislation REACH require the development of new integrated testing strategies rather than applying traditional testing schemes to thousands of chemicals. The current practice of requiring in vivo testing for every possible adverse effect endanger the success of these programmes due (i) to limited testing facilities and sufficient capacity of scientific/technical knowledge for reproductive toxicity; (ii) an unacceptable number of laboratory animals involved (iii) an intolerable number of chemicals classified as false positive. A key aspect of the implementation of new testing strategies is the determination of prevalence of reproductive toxicity in the universe of industrial chemicals. Prevalences are relevant in order to be aware on the expected rate of false classification during the toxicological testing and to implement appropriate measures for their avoidance. Furthermore, a detailed understanding on the subendpoints affected by reproductive toxicants and the underlying mechanisms will lead to more science based testing strategies integrating alternative methods without compromising the protection of consumers.

Ideology Masquerading as Science: The Case of Endocrine Disrupter Screening Programmes

The global move to develop novel testing methods and strategies to identify suspected endocrine disrupting chemicals offers a unique opportunity to move away from traditional animal testing paradigms in this new area of regulatory concern. Regrettably, the programmes under development, both in the USA and internationally through the OECD, have thus far failed to consider in vitro and other non-animal test methods as more than “pre-screening” or “priority-setting” tools in a larger, animal-based testing strategy. Validation efforts to date have focused almost exclusively on the modification of existing animal tests to detect “endocrine effects”, with no demonstrable effort to promote international coordination or support for the development and validation of relevant non-animal test systems. The current orientation in these programmes reflects ideological, rather than scientific, imperatives, and undermines the commitments of both the US government and the OECD with respect to the Three Rs and the minimisation of animal testing.