This article aims to present the diversity of these new models, their applications, their contributions and their limitations, in order to fuel societal debate and inform public decision-making.<\/p>\n
<\/p>\n
<\/span>What are New Approach Methodologies?<\/b><\/span><\/h2>\nThe acronym NAM is a generic term that encompasses a wide range of methods, mainly non-animal, used to explore human biology and generate data on the biological and toxic effects of substances. <\/span><\/p>\nIn simple terms, NAMs seek to answer questions such as: <\/span>Is a substance effective? Is it toxic? At what dose? Through what biological mechanisms?<\/span><\/i>, using scientific strategies that differ from those used in animal models. NAMs are not strictly defined in most regulations. Instead, they are referred to using terms such as \u201calternative or substitute\u201d or \u201cnon-animal\u201d methods. Nevertheless, the term NAM is gradually becoming established to encompass these innovative approaches in scientific, regulatory and industrial circles.<\/span><\/p>\n <\/p>\n
The main categories of NAMs<\/b><\/h2>\n<\/span>In vitro methods: Cell\/tissue culture models<\/b><\/span><\/h3>\nIn vitro<\/em> methods<\/span> are a long-standing and central pillar of NAMs. They involve culturing cells or tissues, often of human origin, in the laboratory in order to observe their responses to substances or physiological or pathological stimuli. <\/span><\/p>\nModels are simple when they comprise a single cell type. In recent years, more complex systems have been developed with different types of cells cultured in 3D: organoids<\/strong><\/a>, reconstructed tissues, tissue sections. Tumoroids<\/strong>, for example, are structures formed from cells taken from patients\u2019 tumours.<\/span><\/p>\n![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/2-cre\u2560udit-Prisca-Liberali_FMI-1024x614.png\")
<\/p>\n
<\/span>Intestine organoid. Image credits: Prisca Liberali\/FMI<\/span><\/span><\/h5>\nThe most advanced models, such as organs-on-chip (OOC)<\/strong>, use fluid circulation in microchannels (known as microfluidics) to precisely control the microenvironment and thus reproduce the interactions between the different cell types that make up an organ, as well as with the dynamic environment in which they live. These microphysiological systems (MPS) involve modulating mechanical and environmental stresses to more accurately reproduce certain aspects of tissue architecture, cellular diversity and interactions specific to human organs.<\/span><\/p>\n![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/1-cre\u2560udit-NETRI-1024x614.png\")
<\/p>\n
<\/span>Organ-on-chip. Image credits: NETRI<\/span><\/span><\/h5>\n <\/p>\n
\n<\/span>Some examples of in vitro<\/em> models<\/span><\/h2>\n\n- Reconstructed human skin or eye models for testing irritation;<\/li>\n
- More advanced three-dimensional systems, organoids or organ-on-a-chip devices, capable of reproducing certain key functions of human organs;<\/li>\n
- Microfluidics coupled with organ-on-a-chip technology to better understand the process of metastasis development, for high-throughput screening of active molecules, or to test the efficacy of treatments.<\/li>\n<\/ul>\n<\/div>\n
<\/h2>\nIn silico<\/em> approaches: mathematical modelling, bioinformatics and AI<\/h2>\nIn silico<\/em> methods are based on computer models that predict the behaviour of substances in biological systems and their interactions with certain targets such as nuclear or membrane receptors, proteins that modify the activity and\/or function of cells in the body. They use existing databases, mathematical models and artificial intelligence tools.<\/p>\nAmong the most common examples in toxicology:<\/p>\n
\n- Read-across<\/strong> approaches, which assume that two chemically similar substances will have similar effects [1<\/a>];<\/li>\n
- SAR<\/strong> (structure\u2009\u2013\u2009activity relationship) models capable of linking the chemical structure of a molecule to its biological or toxic effects, in some cases quantitatively (QSAR) [2<\/a>];<\/li>\n
- PBPK<\/strong> (pharmacokinetics based on physiology) models, which estimate the absorption, distribution, metabolism and elimination of a substance in the human body.<\/li>\n<\/ul>\n
These methods and others (such as 3D modelling) are particularly useful for the initial screening of large libraries of substances, to limit or even replace the usual experimental testing. They also provide, in record time, information on the behaviour of these substances in the body and the targets they are able to reach.<\/p>\n
A rapidly growing concept originating in industry, the digital twin in healthcare is a dynamic model of a patient, organ or physiological process, built from medical, biological, environmental and behavioural data. It can be used to simulate the progression of a disease or the potential effect of a treatment with a view to providing more personalised medicine.<\/p>\n
<\/p>\n
![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/4-1024x614.png\")
<\/p>\n
<\/p>\n
\n<\/span>Focus: Mathematics for numerical modelling<\/span><\/h2>\nMathematics plays a central role in in silico approaches, providing the formal language needed to represent biological phenomena and predict system behaviour. For example, differential equations describe the dynamics within PBPK models, while statistical and multivariate methods enable the construction of (Q)SAR models and the quantification of uncertainties. Optimisation algorithms enable parameter adjustment, sensitivity analysis and scenario exploration. Mathematics also forms the basis of AI-enhanced NAMs, which are capable of transforming biological complexity into computable predictive models, thereby driving safer and more efficient research.<\/p>\n
<\/p>\n<\/div>\n
<\/span>In chemico<\/em> methods: chemistry as a biological indicator<\/span><\/h2>\nIn chemico<\/em> approaches focus on the key chemical reactions involved in toxicity mechanisms, particularly the interaction of substances with proteins (which cause allergic reactions) or with DNA (which causes harmful genetic mutations). They are widely used to measure the effect of substances on skin proteins, which can cause skin sensitisation. Today, the combination of in vitro<\/em> and cell-based tests has replaced most animal testing for skin sensitisation, although some immunological tests are still performed in mice. In the field of drug development, in vitro<\/em> tests are used to assess potential side effects or possible interactions with other drugs.<\/p>\n![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/5-1024x614.png\")
<\/p>\n
<\/p>\n
<\/span>Integrated approaches: combining evidence<\/span><\/h2>\nOne of the major developments in NAMs is the shift from isolated tests to integrated assessment frameworks, combining different data sources to support regulatory decisions. Key concepts include: Adverse Outcome Pathways (AOPs), which describe the chain of events linking an initial molecular interaction to an observable adverse effect; Integrated Approaches to Testing and Assessment (IATA), which rely on combining in silico<\/em>, in chemico<\/em> and in vitro<\/em> data; and Next Generation Risk Assessment (NGRA) approaches, which integrate hazard, exposure and mechanism of action data to assess real risks to humans.
\nIn addition, there are \u201comic\u201d analyses (transcriptomics, proteomics, lipidomics, metabolomics) to measure molecular and biochemical responses in cells, tissues and biological fluids. In toxicology, these approaches are used to characterise and quantify the effects of exposure to chemicals or drugs, contributing to a more mechanistic and predictive assessment.<\/p>\n![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/19-1024x614.png\")
<\/p>\n
<\/p>\n
\nFocus: Myths and misconceptions about NAMs<\/h2>\n
Some common misconceptions about NAMs:<\/p>\n
\n- \u201cNAMs imply the immediate or total end of all animal suffering.\u201d This perception is based on a confusion of terminology. NAMs can be defined as Non-Animal Methods, but they also refer to New Methodological Approaches. Although they are alternatives to animal experimentation, in vitro NAMs may use products of animal origin (serums or matrices).<\/li>\n
- \u201cNAMs are already fully accepted by regulatory authorities.\u201d While agencies are beginning to incorporate NAMs into their recommendations and have accepted some of them, traditional toxicological testing on animals remains widely required.<\/li>\n
- \u201cNAMs are already sufficient to replace all animal testing as a single or universal solution.\u201d NAMs are based on a reasoned combination of models and data, designed to answer specific questions. Their objective is not to \u201cdo without animals at all costs\u201d, but to produce data that is more relevant to humans, within a rigorous and transparent scientific framework.<\/li>\n<\/ul>\n
<\/p>\n<\/div>\n
In which areas are NAMs already being used?<\/h2>\n<\/span>Safety assessment of substances<\/span><\/h3>\nNAMs are incorporated into regulatory assessment in several sectors. Since 2013, animal testing has been prohibited in the EU for cosmetic products and their ingredients when validated alternative methods exist, such as reconstructed human skin models.<\/p>\n
In chemical regulations, particularly REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), companies must avoid animal testing. NAMs (in vitro, in chemico<\/i> and in silico) <\/i>are used via<\/i> weight-of-evidence approaches; animal testing should only be used as a last resort.<\/p>\n
In the food sector, risk assessments (additives, contaminants, contact materials, etc.) are still largely based on animal data, but European authorities are aiming to increase the proportion of data derived from NAMs. Similarly, regulations on biocides and plant protection products (pesticides) promote the reduction of animal testing.<\/p>\n
<\/p>\n
NAMs are also transforming the evaluation of medical devices. Agencies are encouraging their use (particularly in the United States and Japan). Despite these advances, obstacles remain (see next chapter).<\/span><\/p>\n<\/span>NAMs in biomedical research<\/span><\/h3>\nIn biomedical research, NAMs, in vitro and in silico, offer original perspectives not only for better understanding diseases and discovering new targets (biomarkers), but also for developing and testing new therapeutic strategies. Today, approximately 90% of drug candidates validated in preclinical animal tests fail in clinical trials [1<\/a>,2<\/a>]; contributing to a long and costly development process. NAMs, which are more predictive, faster and less costly, have the potential to improve the R&D cycle: understanding mechanisms, screening and optimising therapeutic candidates, evaluating efficacy and side effects, etc.<\/p>\nAnother perspective is to be able to offer treatments tailored to each patient or group of patients, with a view to \u201cstratified\u201d or \u201cpersonalised\u201d medicine. The use of organoids and patient data combined with AI is being considered, for example, for conditions such as cancer, diabetes and neurodegenerative diseases, but also for so-called vulnerable populations (pregnant women, infants, children, etc.).<\/p>\n
In regenerative medicine, combining advanced human models (organoids, organs-on-chips) with 3D bioprinting makes it possible to study tissue repair and regeneration mechanisms with increased biological relevance.<\/p>\n
![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/22-1024x614.png\")
<\/p>\n
<\/p>\n
\nFocus: The added value of NAMs<\/h2>\n
Beyond ethical considerations and the reduction of animal testing, NAMs offer:<\/p>\n
\n- Greater relevance for humans;<\/li>\n
- Access to subtle biological mechanisms that are difficult to observe in global animal models;<\/li>\n
- The ability to produce data earlier in the R&D cycle;<\/li>\n
- Potential gains in efficiency and cost for certain stages;<\/li>\n
- Greater consideration for specific or vulnerable populations.<\/li>\n<\/ul>\n
Today, NAMs appear to be indispensable for understanding:<\/p>\n
\n- The danger posed by exposure to tens of thousands of chemicals whose effects we do not know and for which animal testing does not offer a satisfactory solution (cost, duration, transposition to humans);<\/li>\n
- The issue of chemical mixtures (cocktail effects).<\/li>\n<\/ul>\n
<\/p>\n<\/div>\n
<\/span>Limitations, challenges and conditions for success<\/span><\/h2>\n<\/span>Current scientific limitations<\/span><\/h3>\n <\/p>\n
No model, animal or otherwise, can fully represent the complexity of a human organism. Certain issues, such as long-term systemic effects, interactions between organs, and the impact of complex exposure pathways (e.g., transgenerational alterations), remain difficult to study, even with NAMs. Some tissues, stages of development, or pathological conditions do not yet have sufficiently mature or scientifically validated models. Even though the predictability of animal models for humans does not exceed 65% and the reproducibility of trials is regularly questioned, much remains to be done to move away from animal models, particularly in the decision-making process [3<\/a>].<\/span><\/p>\n<\/span>Validation and standardisation issues<\/span><\/h3>\nIn order to be widely adopted, NAMs must demonstrate their reliability, reproducibility and biological relevance for their intended use. Scientific validation establishes this credibility, in particular through inter-laboratory comparisons and clear interpretation criteria. Where possible, standardising protocols facilitates their adoption and regulatory use. For example, in accordance with the ISO 10993<\/a> standard, authorities favour in vitro<\/i> (cytotoxicity, irritation, sensitisation) and chemical characterisation coupled with in silico modelling (QSAR). The standardisation of new methods, which can be a lengthy and demanding process, is essential to build confidence among authorities, industry and the public. Harmonisation and standardisation initiatives led by the Organisation for Economic Co-operation and Development (OECD) and the International Cooperation on Alternative Test Methods (ICATM) aim to address this challenge.<\/p>\n <\/p>\n
<\/span>Regulatory approval<\/span><\/h3>\nNAMs can be used in innovative approaches to hazard and risk assessment. Numerous initiatives and research projects are promoting greater regulatory acceptance. While some regulations are pioneering, such as those for cosmetics, and some countries encourage their use (e.g. the FDA (Food & Drug Administration), USA) and the PMDA (Pharmaceuticals and Medical Devices Agency), Japan), the regulatory framework for NAMs is still evolving. Drug Administration, USA) and the PMDA (Pharmaceuticals and Medical Devices Agency<\/i><\/a>, Japan), the acceptability of these approaches remains limited at European and global levels. Chronic and environmental effects are still largely assessed on the basis of animal studies. At the same time, mutual recognition of data from NAMs still depends on the validation and standardisation of protocols. Significant work therefore needs to be done to compare existing data in order to help regulatory bodies move towards better integration of NAMs. The International Council for Harmonisation has begun updating the appendices to its guidelines -ICH S7A<\/a> and S7B<\/a>- (particularly for cardiac and hepatic toxicology).<\/p>\n <\/p>\n
<\/span>Interoperability, quality and data sharing<\/span><\/h3>\nInteroperability, quality, and data sharing are key to the rise of NAMs. The diversity of formats, models, and platforms complicates the comparison and reuse of results. However, solutions are gradually emerging, combining common standards, harmonised metadata and FAIR principles (Findable, Accessible, Interoperable, Reusable). The development of secure infrastructures and controlled sharing spaces will improve data quality and access while protecting industrial (particularly sensitive data) and regulatory issues.<\/p>\n
![](\"https:\/\/www.proanima.fr\/wp-content\/uploads\/2026\/02\/15-1024x614.png\")
<\/h3>\n
<\/p>\n
<\/span>Need for new skills<\/span><\/h3>\nNAMs can be a fundamentally different source of data from animal testing, posing a significant challenge to the current system. To ensure that we are able to understand and assimilate them now and in the future, a major effort must be made in terms of training for students, researchers and experts. Training programmes must therefore reflect the complexity and interdisciplinary requirements of NAMs.<\/span><\/p>\n <\/p>\n
<\/span>Socio-technical barriers<\/span><\/h3>\nThe implementation of a valid and accepted method is not only a matter for science, but also for politics, law and society. Out of habit or ignorance, certain influential communities of experts tend to denigrate the usefulness of NAMs and hinder their development. The transition to these new methods requires deep reflection on the foundations of modern research. It requires collective support, bringing together researchers, competent authorities, industry and civil society.<\/span><\/p>\n <\/p>\n
<\/span>Conclusion & Opening<\/span><\/h2>\nThe diversity of uses for NAMs in academic and industrial settings is a strength, although they are not a perfect solution for all research needs. It is therefore essential not to overpromise.<\/p>\n
However, NAMs are establishing themselves as a major scientific and economic lever for transforming biomedical research, toxicology and risk assessment on an international scale. They therefore offer public decision-makers an opportunity to base public health policies on data that is more reliable and transferable to humans, as well as industrial policies based on cutting-edge technologies.<\/p>\n
Their use is set to grow rapidly and the robustness of the models offered will increase, with a view to better understanding and responding to contemporary challenges in health, competitiveness and sovereignty.<\/p>\n
However, accelerating their adoption while ensuring scientific rigour and collective confidence requires a structured approach: training and uniting stakeholders who are still too fragmented, organising shared governance of the transition, and targeted, coordinated investments that are commensurate with the challenges. The speed of progress depends on the resources allocated to validation, research, stakeholder support and infrastructure development.<\/p>\n
Without claiming to be exhaustive on a subject as rich and promising as NAMs, this article outlines its scope, main areas of research and numerous fields of application. Other publications will follow, providing more concrete examples of how these methodologies are implemented, particularly in the area of risk assessment.<\/p>\n
<\/p>\n
Pro Anima Scientific Advisory Board<\/b><\/a><\/p>\n\n<\/span>Focus: The dynamics of tNAM: a global movement<\/span><\/h2>\nAu-del\u00e0 des enjeux \u00e9thiques et de r\u00e9duction de l\u2019exp\u00e9rimentation animale, les NAM offrent :
\nLa dynamique des NAM est mondiale. Aux \u00c9tats-Unis, la prise de conscience de l\u2019int\u00e9r\u00eat des NAM face aux limites des mod\u00e8les animaux a conduit \u00e0 une \u00e9volution r\u00e9glementaire majeure. L\u2019adoption du Food and Drug Administration<\/em> (FDA) Modernization Act<\/em> 2.0 puis 3.0 a supprim\u00e9 l\u2019obligation historique de recourir \u00e0 l\u2019exp\u00e9rimentation animale pour l\u2019enregistrement des m\u00e9dicaments. La FDA a publi\u00e9 des feuilles de route favorisant l\u2019int\u00e9gration de donn\u00e9es issues de mod\u00e8les humains. Parall\u00e8lement, les National Institutes of Health<\/em> (NIH) ont r\u00e9orient\u00e9 leurs financements vers des approches alternatives, tandis que l\u2019Environmental Protection Agency<\/em> (EPA) s\u2019est engag\u00e9e \u00e0 \u00e9liminer progressivement les tests de toxicit\u00e9 sur les mammif\u00e8res. Ces actions s\u2019appuient sur de solides partenariats entre agences f\u00e9d\u00e9rales, institutions acad\u00e9miques et industrie.<\/p>\nL\u2019Europe s\u2019inscrit \u00e9galement dans une dynamique structur\u00e9e. L\u2019Union europ\u00e9enne, \u00e0 travers le Joint Research Center<\/em> (JRC), l\u2019Agence europ\u00e9enne de la chimie et l\u2019Agence europ\u00e9enne des m\u00e9dicaments (EMA), soutient activement la validation et l\u2019acceptation des NAM. L\u2019European Chemicals Agency<\/em> (ECHA) et l\u2019European Partnership for Alternative Approaches to Animal Testing<\/em> (EPAA) favorisent l\u2019harmonisation des pratiques, notamment via les approches int\u00e9gr\u00e9es de test et d\u2019\u00e9valuation. Plusieurs \u00c9tats membres se positionnent en leaders : les Pays-Bas, avec le programme TPI (Transition Programme for Innovation without animal testing<\/em>), la France, avec la structuration de la fili\u00e8re F3OCI (Organo\u00efdes et Organes sur Puce) et la publication d\u2019un Livre Blanc. Le Royaume-Uni d\u00e9veloppe sa propre strat\u00e9gie nationale, soutenue par des investissements cibl\u00e9s et la cr\u00e9ation de centres sp\u00e9cialis\u00e9s.<\/p>\nEn Asie, la dynamique s\u2019intensifie. Le Japon int\u00e8gre progressivement les NAM dans les lignes directrices de la Pharmaceuticals and Medical Devices Agency<\/em> (PMDA). La Cor\u00e9e du Sud renforce ses capacit\u00e9s nationales et s\u2019engage dans des collaborations internationales, tandis que la Chine manifeste un int\u00e9r\u00eat croissant, notamment dans le secteur cosm\u00e9tique.<\/p>\n<\/div>\n<\/span>References<\/span><\/h2>\n\n[1] EFSA Scientific Committee et al., Guidance on the use of read-across for chemical safety assessment in food and feed, EFSA Journal Vol.23 (7) 2025 doi\/full\/10.2903\/j.efsa.2025.9586<\/a><\/p>\n[2] (Q)SAR Assessment Framework: Guidance for the regulatory assessment of (Quantitative) Structure Activity Relationship models and predictions, Second Edition, OECD Series on Testing and Assessment, Nov. 2024, <\/span>doi.org\/10.1787\/bbdac345-en<\/span><\/a><\/p>\n[3] Sun, D, et al. (2022). Why 90% of clinical drug development fails and how to improve it? <\/span>Acta Pharm Sin B<\/span><\/i>., <\/span><\/i>12(7)<\/span>. <\/span>doi.org\/10.1016\/j.apsb.2022.02.002<\/span><\/a><\/p>\n[4] Mirlohi, M.S.; Yousefi, T.; Aref, A.R.; Seyfoori, A. Integrating, New Approach Methodologies (NAMs) into Preclinical Regulatory Evaluation of Oncology Drugs. Biomimetics<\/em> 2025, 10, 796. <\/span>doi.org\/10.3390\/<\/span><\/a>biomimetics10120796<\/a> <\/span><\/p>\n
In simple terms, NAMs seek to answer questions such as: <\/span>Is a substance effective? Is it toxic? At what dose? Through what biological mechanisms?<\/span><\/i>, using scientific strategies that differ from those used in animal models. NAMs are not strictly defined in most regulations. Instead, they are referred to using terms such as \u201calternative or substitute\u201d or \u201cnon-animal\u201d methods. Nevertheless, the term NAM is gradually becoming established to encompass these innovative approaches in scientific, regulatory and industrial circles.<\/span><\/p>\n <\/p>\n In vitro<\/em> methods<\/span> are a long-standing and central pillar of NAMs. They involve culturing cells or tissues, often of human origin, in the laboratory in order to observe their responses to substances or physiological or pathological stimuli. <\/span><\/p>\n Models are simple when they comprise a single cell type. In recent years, more complex systems have been developed with different types of cells cultured in 3D: organoids<\/strong><\/a>, reconstructed tissues, tissue sections. Tumoroids<\/strong>, for example, are structures formed from cells taken from patients\u2019 tumours.<\/span><\/p>\n The most advanced models, such as organs-on-chip (OOC)<\/strong>, use fluid circulation in microchannels (known as microfluidics) to precisely control the microenvironment and thus reproduce the interactions between the different cell types that make up an organ, as well as with the dynamic environment in which they live. These microphysiological systems (MPS) involve modulating mechanical and environmental stresses to more accurately reproduce certain aspects of tissue architecture, cellular diversity and interactions specific to human organs.<\/span><\/p>\n <\/p>\n In silico<\/em> methods are based on computer models that predict the behaviour of substances in biological systems and their interactions with certain targets such as nuclear or membrane receptors, proteins that modify the activity and\/or function of cells in the body. They use existing databases, mathematical models and artificial intelligence tools.<\/p>\n Among the most common examples in toxicology:<\/p>\n These methods and others (such as 3D modelling) are particularly useful for the initial screening of large libraries of substances, to limit or even replace the usual experimental testing. They also provide, in record time, information on the behaviour of these substances in the body and the targets they are able to reach.<\/p>\n A rapidly growing concept originating in industry, the digital twin in healthcare is a dynamic model of a patient, organ or physiological process, built from medical, biological, environmental and behavioural data. It can be used to simulate the progression of a disease or the potential effect of a treatment with a view to providing more personalised medicine.<\/p>\n <\/p>\n <\/p>\n Mathematics plays a central role in in silico approaches, providing the formal language needed to represent biological phenomena and predict system behaviour. For example, differential equations describe the dynamics within PBPK models, while statistical and multivariate methods enable the construction of (Q)SAR models and the quantification of uncertainties. Optimisation algorithms enable parameter adjustment, sensitivity analysis and scenario exploration. Mathematics also forms the basis of AI-enhanced NAMs, which are capable of transforming biological complexity into computable predictive models, thereby driving safer and more efficient research.<\/p>\n <\/p>\n<\/div>\n In chemico<\/em> approaches focus on the key chemical reactions involved in toxicity mechanisms, particularly the interaction of substances with proteins (which cause allergic reactions) or with DNA (which causes harmful genetic mutations). They are widely used to measure the effect of substances on skin proteins, which can cause skin sensitisation. Today, the combination of in vitro<\/em> and cell-based tests has replaced most animal testing for skin sensitisation, although some immunological tests are still performed in mice. In the field of drug development, in vitro<\/em> tests are used to assess potential side effects or possible interactions with other drugs.<\/p>\n <\/p>\n One of the major developments in NAMs is the shift from isolated tests to integrated assessment frameworks, combining different data sources to support regulatory decisions. Key concepts include: Adverse Outcome Pathways (AOPs), which describe the chain of events linking an initial molecular interaction to an observable adverse effect; Integrated Approaches to Testing and Assessment (IATA), which rely on combining in silico<\/em>, in chemico<\/em> and in vitro<\/em> data; and Next Generation Risk Assessment (NGRA) approaches, which integrate hazard, exposure and mechanism of action data to assess real risks to humans. <\/p>\n Some common misconceptions about NAMs:<\/p>\n <\/p>\n<\/div>\n NAMs are incorporated into regulatory assessment in several sectors. Since 2013, animal testing has been prohibited in the EU for cosmetic products and their ingredients when validated alternative methods exist, such as reconstructed human skin models.<\/p>\n In chemical regulations, particularly REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), companies must avoid animal testing. NAMs (in vitro, in chemico<\/i> and in silico) <\/i>are used via<\/i> weight-of-evidence approaches; animal testing should only be used as a last resort.<\/p>\n In the food sector, risk assessments (additives, contaminants, contact materials, etc.) are still largely based on animal data, but European authorities are aiming to increase the proportion of data derived from NAMs. Similarly, regulations on biocides and plant protection products (pesticides) promote the reduction of animal testing.<\/p>\n <\/p>\n NAMs are also transforming the evaluation of medical devices. Agencies are encouraging their use (particularly in the United States and Japan). Despite these advances, obstacles remain (see next chapter).<\/span><\/p>\n In biomedical research, NAMs, in vitro and in silico, offer original perspectives not only for better understanding diseases and discovering new targets (biomarkers), but also for developing and testing new therapeutic strategies. Today, approximately 90% of drug candidates validated in preclinical animal tests fail in clinical trials [1<\/a>,2<\/a>]; contributing to a long and costly development process. NAMs, which are more predictive, faster and less costly, have the potential to improve the R&D cycle: understanding mechanisms, screening and optimising therapeutic candidates, evaluating efficacy and side effects, etc.<\/p>\n Another perspective is to be able to offer treatments tailored to each patient or group of patients, with a view to \u201cstratified\u201d or \u201cpersonalised\u201d medicine. The use of organoids and patient data combined with AI is being considered, for example, for conditions such as cancer, diabetes and neurodegenerative diseases, but also for so-called vulnerable populations (pregnant women, infants, children, etc.).<\/p>\n In regenerative medicine, combining advanced human models (organoids, organs-on-chips) with 3D bioprinting makes it possible to study tissue repair and regeneration mechanisms with increased biological relevance.<\/p>\n <\/p>\n Beyond ethical considerations and the reduction of animal testing, NAMs offer:<\/p>\n Today, NAMs appear to be indispensable for understanding:<\/p>\n <\/p>\n<\/div>\n <\/p>\n No model, animal or otherwise, can fully represent the complexity of a human organism. Certain issues, such as long-term systemic effects, interactions between organs, and the impact of complex exposure pathways (e.g., transgenerational alterations), remain difficult to study, even with NAMs. Some tissues, stages of development, or pathological conditions do not yet have sufficiently mature or scientifically validated models. Even though the predictability of animal models for humans does not exceed 65% and the reproducibility of trials is regularly questioned, much remains to be done to move away from animal models, particularly in the decision-making process [3<\/a>].<\/span><\/p>\n In order to be widely adopted, NAMs must demonstrate their reliability, reproducibility and biological relevance for their intended use. Scientific validation establishes this credibility, in particular through inter-laboratory comparisons and clear interpretation criteria. Where possible, standardising protocols facilitates their adoption and regulatory use. For example, in accordance with the ISO 10993<\/a> standard, authorities favour in vitro<\/i> (cytotoxicity, irritation, sensitisation) and chemical characterisation coupled with in silico modelling (QSAR). The standardisation of new methods, which can be a lengthy and demanding process, is essential to build confidence among authorities, industry and the public. Harmonisation and standardisation initiatives led by the Organisation for Economic Co-operation and Development (OECD) and the International Cooperation on Alternative Test Methods (ICATM) aim to address this challenge.<\/p>\n <\/p>\n NAMs can be used in innovative approaches to hazard and risk assessment. Numerous initiatives and research projects are promoting greater regulatory acceptance. While some regulations are pioneering, such as those for cosmetics, and some countries encourage their use (e.g. the FDA (Food & Drug Administration), USA) and the PMDA (Pharmaceuticals and Medical Devices Agency), Japan), the regulatory framework for NAMs is still evolving. Drug Administration, USA) and the PMDA (Pharmaceuticals and Medical Devices Agency<\/i><\/a>, Japan), the acceptability of these approaches remains limited at European and global levels. Chronic and environmental effects are still largely assessed on the basis of animal studies. At the same time, mutual recognition of data from NAMs still depends on the validation and standardisation of protocols. Significant work therefore needs to be done to compare existing data in order to help regulatory bodies move towards better integration of NAMs. The International Council for Harmonisation has begun updating the appendices to its guidelines -ICH S7A<\/a> and S7B<\/a>- (particularly for cardiac and hepatic toxicology).<\/p>\n <\/p>\n Interoperability, quality, and data sharing are key to the rise of NAMs. The diversity of formats, models, and platforms complicates the comparison and reuse of results. However, solutions are gradually emerging, combining common standards, harmonised metadata and FAIR principles (Findable, Accessible, Interoperable, Reusable). The development of secure infrastructures and controlled sharing spaces will improve data quality and access while protecting industrial (particularly sensitive data) and regulatory issues.<\/p>\n <\/p>\n NAMs can be a fundamentally different source of data from animal testing, posing a significant challenge to the current system. To ensure that we are able to understand and assimilate them now and in the future, a major effort must be made in terms of training for students, researchers and experts. Training programmes must therefore reflect the complexity and interdisciplinary requirements of NAMs.<\/span><\/p>\n <\/p>\n The implementation of a valid and accepted method is not only a matter for science, but also for politics, law and society. Out of habit or ignorance, certain influential communities of experts tend to denigrate the usefulness of NAMs and hinder their development. The transition to these new methods requires deep reflection on the foundations of modern research. It requires collective support, bringing together researchers, competent authorities, industry and civil society.<\/span><\/p>\n <\/p>\n The diversity of uses for NAMs in academic and industrial settings is a strength, although they are not a perfect solution for all research needs. It is therefore essential not to overpromise.<\/p>\n However, NAMs are establishing themselves as a major scientific and economic lever for transforming biomedical research, toxicology and risk assessment on an international scale. They therefore offer public decision-makers an opportunity to base public health policies on data that is more reliable and transferable to humans, as well as industrial policies based on cutting-edge technologies.<\/p>\n Their use is set to grow rapidly and the robustness of the models offered will increase, with a view to better understanding and responding to contemporary challenges in health, competitiveness and sovereignty.<\/p>\n However, accelerating their adoption while ensuring scientific rigour and collective confidence requires a structured approach: training and uniting stakeholders who are still too fragmented, organising shared governance of the transition, and targeted, coordinated investments that are commensurate with the challenges. The speed of progress depends on the resources allocated to validation, research, stakeholder support and infrastructure development.<\/p>\n Without claiming to be exhaustive on a subject as rich and promising as NAMs, this article outlines its scope, main areas of research and numerous fields of application. Other publications will follow, providing more concrete examples of how these methodologies are implemented, particularly in the area of risk assessment.<\/p>\n <\/p>\n Pro Anima Scientific Advisory Board<\/b><\/a><\/p>\n Au-del\u00e0 des enjeux \u00e9thiques et de r\u00e9duction de l\u2019exp\u00e9rimentation animale, les NAM offrent : L\u2019Europe s\u2019inscrit \u00e9galement dans une dynamique structur\u00e9e. L\u2019Union europ\u00e9enne, \u00e0 travers le Joint Research Center<\/em> (JRC), l\u2019Agence europ\u00e9enne de la chimie et l\u2019Agence europ\u00e9enne des m\u00e9dicaments (EMA), soutient activement la validation et l\u2019acceptation des NAM. L\u2019European Chemicals Agency<\/em> (ECHA) et l\u2019European Partnership for Alternative Approaches to Animal Testing<\/em> (EPAA) favorisent l\u2019harmonisation des pratiques, notamment via les approches int\u00e9gr\u00e9es de test et d\u2019\u00e9valuation. Plusieurs \u00c9tats membres se positionnent en leaders : les Pays-Bas, avec le programme TPI (Transition Programme for Innovation without animal testing<\/em>), la France, avec la structuration de la fili\u00e8re F3OCI (Organo\u00efdes et Organes sur Puce) et la publication d\u2019un Livre Blanc. Le Royaume-Uni d\u00e9veloppe sa propre strat\u00e9gie nationale, soutenue par des investissements cibl\u00e9s et la cr\u00e9ation de centres sp\u00e9cialis\u00e9s.<\/p>\n En Asie, la dynamique s\u2019intensifie. Le Japon int\u00e8gre progressivement les NAM dans les lignes directrices de la Pharmaceuticals and Medical Devices Agency<\/em> (PMDA). La Cor\u00e9e du Sud renforce ses capacit\u00e9s nationales et s\u2019engage dans des collaborations internationales, tandis que la Chine manifeste un int\u00e9r\u00eat croissant, notamment dans le secteur cosm\u00e9tique.<\/p>\n<\/div>\n [1] EFSA Scientific Committee et al., Guidance on the use of read-across for chemical safety assessment in food and feed, EFSA Journal Vol.23 (7) 2025 doi\/full\/10.2903\/j.efsa.2025.9586<\/a><\/p>\n [2] (Q)SAR Assessment Framework: Guidance for the regulatory assessment of (Quantitative) Structure Activity Relationship models and predictions, Second Edition, OECD Series on Testing and Assessment, Nov. 2024, <\/span>doi.org\/10.1787\/bbdac345-en<\/span><\/a><\/p>\n [3] Sun, D, et al. (2022). Why 90% of clinical drug development fails and how to improve it? <\/span>Acta Pharm Sin B<\/span><\/i>., <\/span><\/i>12(7)<\/span>. <\/span>doi.org\/10.1016\/j.apsb.2022.02.002<\/span><\/a><\/p>\n [4] Mirlohi, M.S.; Yousefi, T.; Aref, A.R.; Seyfoori, A. Integrating, New Approach Methodologies (NAMs) into Preclinical Regulatory Evaluation of Oncology Drugs. Biomimetics<\/em> 2025, 10, 796. <\/span>doi.org\/10.3390\/<\/span><\/a>biomimetics10120796<\/a> <\/span><\/p>\nThe main categories of NAMs<\/b><\/h2>\n
<\/span>In vitro methods: Cell\/tissue culture models<\/b><\/span><\/h3>\n
<\/p>\n<\/span>Intestine organoid. Image credits: Prisca Liberali\/FMI<\/span><\/span><\/h5>\n
<\/p>\n<\/span>Organ-on-chip. Image credits: NETRI<\/span><\/span><\/h5>\n
<\/span>Some examples of in vitro<\/em> models<\/span><\/h2>\n
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<\/h2>\n
In silico<\/em> approaches: mathematical modelling, bioinformatics and AI<\/h2>\n
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<\/p>\n<\/span>Focus: Mathematics for numerical modelling<\/span><\/h2>\n
<\/span>In chemico<\/em> methods: chemistry as a biological indicator<\/span><\/h2>\n
<\/p>\n<\/span>Integrated approaches: combining evidence<\/span><\/h2>\n
\nIn addition, there are \u201comic\u201d analyses (transcriptomics, proteomics, lipidomics, metabolomics) to measure molecular and biochemical responses in cells, tissues and biological fluids. In toxicology, these approaches are used to characterise and quantify the effects of exposure to chemicals or drugs, contributing to a more mechanistic and predictive assessment.<\/p>\n<\/p>\nFocus: Myths and misconceptions about NAMs<\/h2>\n
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In which areas are NAMs already being used?<\/h2>\n
<\/span>Safety assessment of substances<\/span><\/h3>\n
<\/span>NAMs in biomedical research<\/span><\/h3>\n
<\/p>\nFocus: The added value of NAMs<\/h2>\n
\n
\n
<\/span>Limitations, challenges and conditions for success<\/span><\/h2>\n
<\/span>Current scientific limitations<\/span><\/h3>\n
<\/span>Validation and standardisation issues<\/span><\/h3>\n
<\/span>Regulatory approval<\/span><\/h3>\n
<\/span>Interoperability, quality and data sharing<\/span><\/h3>\n
<\/h3>\n<\/span>Need for new skills<\/span><\/h3>\n
<\/span>Socio-technical barriers<\/span><\/h3>\n
<\/span>Conclusion & Opening<\/span><\/h2>\n
<\/span>Focus: The dynamics of tNAM: a global movement<\/span><\/h2>\n
\nLa dynamique des NAM est mondiale. Aux \u00c9tats-Unis, la prise de conscience de l\u2019int\u00e9r\u00eat des NAM face aux limites des mod\u00e8les animaux a conduit \u00e0 une \u00e9volution r\u00e9glementaire majeure. L\u2019adoption du Food and Drug Administration<\/em> (FDA) Modernization Act<\/em> 2.0 puis 3.0 a supprim\u00e9 l\u2019obligation historique de recourir \u00e0 l\u2019exp\u00e9rimentation animale pour l\u2019enregistrement des m\u00e9dicaments. La FDA a publi\u00e9 des feuilles de route favorisant l\u2019int\u00e9gration de donn\u00e9es issues de mod\u00e8les humains. Parall\u00e8lement, les National Institutes of Health<\/em> (NIH) ont r\u00e9orient\u00e9 leurs financements vers des approches alternatives, tandis que l\u2019Environmental Protection Agency<\/em> (EPA) s\u2019est engag\u00e9e \u00e0 \u00e9liminer progressivement les tests de toxicit\u00e9 sur les mammif\u00e8res. Ces actions s\u2019appuient sur de solides partenariats entre agences f\u00e9d\u00e9rales, institutions acad\u00e9miques et industrie.<\/p>\n<\/span>References<\/span><\/h2>\n