ICCVAM Biennial Report 2024-2025

ICCVAM agency scientists participate in programs coordinated by the Health and Environmental Sciences Institute (HESI). HESI collaboratively identifies and helps to resolve global health and environmental challenges through the engagement of scientists from academia, government, industry, nongovernmental organizations, and other strategic partners. In 2024 and 2025, ICCVAM agency scientists participated in the following HESI projects.

• tPODs for Chemical Risk Assessments Working Group: This working group is developing a comprehensive, multilayered methodological framework for deriving transcriptomic points-of-departure (tPODs) from short-term in vivo toxicity studies for ecological and human health chemical assessments. The goal is to develop tPODs that are stable, biologically meaningful, and suitable for use in chemical risk assessment. A 2025 workshop advanced this effort by addressing study design considerations, establishing upstream quality control practices to improve data harmonization, defining standardized approaches for transcriptomic benchmark dose modeling, and evaluating both gene level and gene set based summarization strategies for consistent tPOD derivation. Outcomes from the workshop are being prepared as several manuscripts. The working group has also emphasized opportunities to reduce and refine animal use by demonstrating how mechanistic studies that incorporate transcriptomics and other molecular data could help replace traditional animal-intensive developmental and reproductive toxicity (DART) studies. These concepts will be featured in a roundtable at the 2026 Society of Toxicology annual meeting, “Towards a New Paradigm: Can Mechanistic In Vivo Studies Replace Traditional DART Guideline Studies?” that will be summarized into a short communication for publication.
• Cell Painting - OASIS Consortium: The HESI-sponsored Omics for Assessing Signatures for Integrated Safety (OASIS) Consortium is advancing next-generation risk assessment by integrating multiomics technologies, including transcriptomics, proteomics, and high-content cell painting, across a range of human-relevant biological systems. With an initial focus on liver safety, the consortium is combining molecular and phenotypic data from rat and human cell line exposures to well-characterized reference chemicals to improve translation from in vitro findings to in vivo and clinical outcomes. Chemical testing and data acquisition have recently been completed, and analysis is now underway to compare transcriptomic responses with phenotypic profiles generated through cell painting. Through this work, the consortium aims to build more predictive, efficient, and human-relevant approaches to chemical safety assessment, while supporting reduced reliance on animal models and strengthening regulatory science across sectors.
• eSTAR MicroRNA Biomarkers Working Group: Previous work within the Emerging Systems Toxicology for the Assessment of Risk (eSTAR) MicroRNA Biomarkers Working Group identified candidate microRNA biomarkers for kidney toxicity (Chorley et al. 2021; Dasgupta et al. 2024). More recent work focused on NAMs development by measuring extracellular release of these biomarkers in human primary proximal tubule cell culture media after exposure to kidney toxicants. Results from the study, now in preparation for publication, are part of the working group’s long-term efforts to develop biomarkers based on extracellular microRNA released by region-specific nephron cells that are indicative of toxicity due to chemical or drug exposure. These biomarkers can be utilized as nondestructive, time-course measures in cell culture media.
• eSTAR Carcinogenomics Working Group: This working group is developing transcriptomic signatures to detect early molecular events that are associated with liver tumorigenic outcomes in short-term rodent studies. Using publicly available rat liver gene expression datasets, machine learning, expert biological review, and HESI-sponsored studies from wild-type and receptor-null rat models, the group is building concise gene sets that are sensitive and specific for the activation of key tumor-associated pathways, including AhR, CAR, PPARα, ER, PXR, p53, and cytotoxicity. In particular, the receptor-null rat models were leveraged to confirm signature gene responses that require the tumor-associated receptor. The goal is to support mechanistically informed, weight-of-evidence approaches for assessing carcinogenic potential in short-term studies and to help reduce the need for traditional two-year rodent carcinogenicity assays in alignment with guidance S1B(R1) issued by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use.

The Botanical Safety Consortium is a public-private partnership advancing the scientific study of botanical ingredients to improve safety assessments. The Consortium combines expertise from federal agencies, academia, and industry to address gaps in the reliable evaluation of botanical substances, which are gaining popularity as dietary supplements and consumer products. Recent updates from the Consortium highlight efforts to establish robust methods and frameworks for assessing botanical safety. These achievements reflect the Consortium’s commitment to improving the scientific foundation of botanical safety evaluation while supporting principles of replacement, reduction, and refinement of animal use.

• Identification of best practices for in vitro botanical safety testing: A group of Consortium researchers, including NIEHS scientists, reviewed methodologies for assessing botanical ingredients in vitro (Waidyanatha et al. 2024). The study underlined the importance of standardized protocols to reduce variability in test results and emphasized the critical role of understanding the complex interactions within botanicals to develop reliable testing strategies.
• Chemical identification to support botanical identity: A key activity of the Consortium is the compilation of data to support the identification of botanicals. These data are available via the National Toxicology Program’s Chemical Effects in Biological Systems database. Updates to the dataset in July 2024 added data for Ephedra sinica, and October 2024 updates added data on Nerium oleander and Aconitum napellus.
• Collaborative efforts and new resources: The Botanical Safety Consortium continues to expand its initiatives through Technical Working Group projects that integrate scientific advancements and promote data sharing. Currently active working groups focus on Chemical Analysis, Developmental and Reproductive Toxicity, Hepatotoxicity, Genotoxicity, Dermal Toxicity, Data Analysis, Cardiotoxicity, Neurotoxicity, and Pharmacognosy.

NCI has established several collaborations among researchers and organizations to facilitate knowledge, data, and resource sharing to help address the most challenging questions in cancer research. Several of these collaborations are relevant to development of NAMs such as computational approaches and complex in vitro models.

• The Human Cancer Models Initiative (HCMI), a collaboration between the NCI, Cancer Research UK, Wellcome Sanger Institute, and Hubrecht Organoid Technology, is a community resource consisting of patient-derived next-generation cancer models (including organoids, neurospheres, and cell lines) and their associated molecular and clinical data. To date, HCMI has generated 783 models, 337 of which are currently available for purchase via the American Type Culture Collection. Users may express interest in HCMI models that have not yet been expanded and made available for purchase via the American Type Culture Collection’s Unmanufactured Models webpage. HCMI models can be browsed using the HCMI Searchable Catalog, a continuously updated resource. Clinical and molecular data are available for 664 models through NCI's Genomic Data Commons. Additional models are being generated to fill gaps in the HCMI cohort (i.e., rare cancers, pediatric cancers, cancers from poorly represented demographic groups), and model-associated molecular data continue to be generated.
   
• The Cancer Systems Biology Consortium provides an interdisciplinary forum to leverage systems analysis and predictive modeling to address the most perplexing issues in cancer. The Consortium’s goals include:
  • Advancing understanding of mechanisms that underlie fundamental processes in cancer
  • Supporting the broad application of systems biology approaches in cancer research
  • Supporting the growth of a strong, stable, and diverse research community in cancer systems biology

Members participate in working groups and Steering Committee meetings, as well as an annual meeting. Consortium members share computational approaches and data through the Cancer Complexity Knowledge Portal. Researchers that have been awarded a Consortium grant are members of this research community. Associate membership is also available to researchers and advocates who have not received grants.

• The Physical Sciences – Oncology Network brings together cancer biologists and oncologists with scientists from the fields of physics, mathematics, chemistry, and engineering to address some of the major questions and barriers in cancer research. The goal of the network is to foster the convergence of physical sciences approaches and perspectives with cancer research to advance our understanding of oncology through transdisciplinary team science. Current funded projects include the development of computational models of cell state networks in glioblastoma and mathematical models to predict treatment responses for acute myeloid leukemia.

The NIH Organoid Models Interest Group promotes the adoption, standardization, and proper use of organoid systems across the NIH Intramural Research Program. This group acts as a catalyst to connect current organoid users with potential adopters. It provides onboarding resources, benchmarks protocols, and highlights resources developed across the Intramural Research Program, including the NIH Standardized Organoid Modeling Center. These efforts will complement the work of Intramural Research Program scientists supporting NIH’s broader goal of integrating NAMs, including organoids, into a diverse research toolkit.

A contaminant of emerging concern is a material with no regulatory standard, that may induce toxicity at lower levels of exposure than previously characterized, is challenging to address across jurisdictions, and presents challenges for timely information‑sharing with stakeholders. Many contaminants of emerging concern are of interest to multiple federal agencies, which has given rise to efforts to coordinate addressing them. The Contaminants of Emerging Concern Interagency Working Group coordinated federal programs and activities to address contaminants of emerging concern; 18 agencies were involved, including eight ICCVAM member agencies. A 2022 report issued by the working group summarized current government activities and future needs. Specifically, the report articulated a vision to provide access to clean and plentiful drinking water for everyone in the U.S. and specified five goals to achieve this. Three coordination teams were established to focus on (1) nontargeted analysis and effects-based monitoring to discover and screen contaminants of emerging concern, (2) characterizing risk by assessing potential hazards and exposure, and (3) formulating joint solicitations across agencies. A 2024 implementation plan to address this last activity outlined a series of short- and long-term activities that are anchored to success metrics and identified NAMs as a critical tool for potential hazard characterization.

The Promise to Address Comprehensive Toxics Act of 2022 provided resources and intent to improve and expand healthcare to veterans who were exposed to toxic substances during their military service. Understanding past exposure events and their potential influence on health is a requirement for providing informed care and reducing the probability of future adverse events. This need drove the establishment of an interagency group to outline a strategy to fill research and data gaps associated with toxic exposures during military service. The Toxic Exposure Research Working Group, which included representatives of seven ICCVAM agencies, was initiated to help scope the problem, outline goals, objectives, and tasks that could be reasonably accomplished in five years to help address some of these gaps. The working group’s goals included:

1. Improving understanding of the military exposome.
2. Prioritizing and linking military exposures to toxicity and adverse health outcomes, including understanding modes-of-action and adverse outcome pathways.
3. Investigating associations and interplay between priority military toxic exposures, toxicological endpoints, and adverse health outcomes.
4. Preventing and mitigating military adverse health outcomes from military exposures.
5. Communicate toxic exposure risk and adverse health outcomes to relevant stakeholders to enhance exposure-informed care.

Objectives and tasks were developed with the intention of fostering interagency cooperation to establish a federal infrastructure framework for coordinating implementation of this strategic plan. The working group’s final report, issued in 2024, addressed requirements of the Promise to Address Comprehensive Toxics Act to outline goals in this area over the next five years. ICCVAM co-chair Natalia Garcia-Reyero Vinas, Ph.D., served on the working group’s Strategy Team.

EPA computational toxicology researchers are developing and using new approaches to evaluate the potential health effects of chemicals. As part of this effort, EPA’s Center for Computational Toxicology and Exposure and Unilever’s Safety and Environmental Assurance Centre established a cooperative research and development agreement aimed at the development and evaluation of NAMs for use in next-generation risk assessment. A set of 40 case study chemicals representing common natural ingredients found in consumer products were used to explore the utility of a battery of NAMs for evaluating their safety and potential hazards. Research topics in this project include:

• Exploring how combinations of screening approaches using biologically diverse human cell lines can be applied to determining molecular points-of-departure (PODs). Screening approaches included safety pharmacology screening, cell stress assay panels, and high-throughput transcriptomic and imaging-based phenotypic profiling assays.
• Comparing molecular PODs to human exposure levels in hazardous and nonhazardous exposure scenarios.
• Incorporating metabolic competence into high-throughput profiling assays. This study (Jurgelewicz et al. 2025) demonstrated that high-throughput profiling assays can reproducibly detect changes in chemical bioactivity between parent compounds and metabolites generated using the previously developed Alginate Immobilization of Metabolic Enzymes platform.

The project was discussed in an April 2024 webinar presented by Physicians Committee for Responsible Medicine.

NIEHS and EPA are fostering a community-driven initiative, the Environmental Health Language Collaborative. The Collaborative is a community for those who generate, analyze, or manage environmental health science (EHS) data and want to ensure the data are formatted and annotated using common EHS language standards to promote data discovery, interoperability, and reuse. The Collaborative is addressing this mission through three high-level strategic goals:

• Foster community-based extension and development of vocabularies, terminologies, and ontologies, and develop methods and tools to apply those resources
• Apply language standards and best practices for accurate environmental health data and knowledge representation
• Cultivate a vocabulary-aware environmental health community through training and education

The Collaborative’s website has resources including a glossary, bibliography, links to ontologies, and overview videos.

The Collaborative presented six webinars during 2024 and 2025 and held a two-day international workshop in June 2025 on the standardization of adverse outcome pathways. Videos and materials from the webinars and workshops are available on the Collaborative’s website. The Collaborative also maintains use-case working groups to explore language solutions that will enhance the findability, reuse, and/or operability of environmental health and safety data. Current working groups are focused on the use cases of “Biomarkers and Biological Processes of Exposure,” “Data Discovery,” and “Data Harmonization.” All working groups meet periodically and welcome new members. The Data Harmonization Use Case working group submitted a manuscript in 2025 (Stingone et al. 2026) and is working on two additional papers. Other use cases have manuscripts in preparation.

An AOP is a conceptual framework for organizing information and evidence of toxicity. It defines a causal relationship between perturbation of a biological pathway at the molecular, biochemical, or cellular level and one or more resulting adverse outcomes to human or ecosystem health. AOPs are useful in supporting both the development and application of NAMs and defined approaches in chemical safety assessment because they can:

• Organize information about biological interactions and toxicity mechanisms into sequential steps that describe how exposure to a substance might cause illness or injury.
• Suggest cell- or biochemical-based tests for pathway elements that could be used to develop testing strategies for targeted toxicity.
• Identify steps in a toxicity mechanism that need improved characterization.

EPA is an active partner in the AOP Development Programme, which is managed by the Organisation for Economic Co-operation and Development (OECD) Advisory Group on Emerging Science in Chemicals Assessment. EPA is also an active participant in the Society for the Advancement of Adverse Outcome Pathways, which promotes and advances scientific research that fosters the development and use of AOPs. The Society hosts the AOP-Wiki, which is one component of a larger OECD-coordinated AOP Knowledgebase, previously supported by EPA. In 2025, it was announced that all members of the Society should transition to becoming either members of the American Society for Cellular and Computational Toxicology or the European Society for Toxicology In Vitro and continue work to support development of AOPs via interest groups within each of the broader NAMs-focused societies.

EPA and NIEHS also work with international partners in the Methods2AOP Collaboration, which seeks to develop infrastructure to accommodate the integration of defined method details with key events in AOPs. This connection between specific test methods/assays and key events in AOPs can facilitate improved interpretation of likely chemical hazards of substances shown to elicit a given assay or endpoint response. A paper describing the Methods2AOP Collaboration’s activities (Karmaus et al. 2026) describes outreach events held in 2024 to facilitate stakeholder engagement. The Collaboration proposes the establishment of standardized fields for AOP documentation that leverage controlled vocabularies/ontologies alongside existing free-text options. They noted the continuing need for guidance for method developers embarking on validation studies and encouraged consideration of how changes to the AOP Knowledgebase and AOP-Wiki might impact third-party tools.

In a parallel effort, the FAIR Cluster Workgroup, an international collaboration in which EPA also participated, considered how available AOP resources might better support FAIR principles (findability, accessibility, interoperability, and reusability of data). Their recommendations (Mortensen et al. 2025) included coordination of mechanistic process mapping to molecular identifiers, and they identified a need for a workflow that stacks the curation process with domain expertise and tools. They also identified ongoing data standardization efforts that should support the application of FAIR principles to AOPs. The topic was explored further at the NIEHS-EPA coordinated Environmental Health Language Collaborative AOP Standards Workshop (Mortensen et al. 2026), where AOP and biomedical data experts deliberated on how to incorporate AOP associated biomedical data into existing or prototype AOP-Wiki data frameworks.

Microphysiological systems (MPS), also frequently referred to as “tissue chips” or “organs-on-chips” are in vitro platforms composed of cells, explants derived from tissues or organs, or organoid cell formations. The cells and tissues, which may be of human or animal origin, are maintained in a microenvironment that provides and supports the biochemical, electrical, and mechanical responses to model the specific properties that define the function of the organ or tissue of interest. Over the past decade, a broad variety of MPS models and systems have emerged. To facilitate the collaboration and cooperation needed to appropriately support further development and acceptance of MPS, international companies and organizations teamed up in 2021 to initiate annual MPS World Summits. These meetings present the latest scientific achievements, discuss advances and challenges, and enable communication between young and newly interested scientists and pioneers in the MPS field.

The World Summits are organized by the International MPS Society, which was established in 2023 to connect, exchange, and educate to promote the international standardization and harmonization of MPS, establish a global training environment, and maximize the potential of MPS to advance the life sciences. At the 2024 World Summit, NIST organized a “Workshop for Advancing Standards and Regulatory Science for MPS and Microfluidic-based Medical Products” that included members of the Microfluidics Association and members of the International MPS Society Standardization Interest Group. The 1½-day workshop gathered participants and speakers from over 15 countries and was attended by over 120 people. It covered a wide range of topics and featured 25 speakers discussing their work in areas of microfluidics-based medical devices as well as on research and standardization efforts in MPS.

The 2026 MPS World Summit will be held in Washington, DC, and scientists in the FDA Human Foods Program (HFP) are on the organizing committee.

FDA Human Foods Program (HFP; formerly the Center for Food Safety and Applied Nutrition) is committed to rapid responses to food supply threats, focusing on faster and more efficient ways to identify toxicity and related pathways. Traditional animal studies take months or years to complete, which is unacceptable in today's global market. To address this challenge, HFP has prioritized the development and implementation of NAMs within four key areas:

1. Center Activities and Partnerships: A NAMs Working Group has been established with representatives from the FDA Offices of Food Additive Safety, Dietary Supplement Programs, Analytics and Outreach, Regulatory Science, and Applied Research and Safety Assessment. HFP is leading the development of NAMs that could provide timelier and more detailed safety information, particularly as legislation aiming to ban animal testing for cosmetics safety gains traction. The focus includes qualifying new methodologies for regulatory decisions.
2. Agency Activities and Partnerships: Currently, there are no training courses on the application of NAMs and corresponding data for regulatory use. HFP’s “Training by Doing” program involves early-career scientists in NAMs committees, providing opportunities to develop expertise, identify data gaps, and report to senior management. The program fosters confidence in regulatory applications of NAMs.
3. Cross-Federal Agency Activities: HFP has cochaired several NAMs workshops, and an Alternative Methods Working Group has been established. Chaired by Drs. Suzanne Fitzpatrick (HFP) and Qiang Shi (National Center for Toxicological Research), the working group includes regulatory and research members from each FDA Center, the National Center for Toxicological Research, and the FDA Office of the Chief Scientist. The goal is to discuss alternative activities across FDA and provide external representation of FDA alternative activities.
4. Global Activities and Partnerships: Alongside the European Food Safety Authority, HFP has established the International Liaison Group on Methods for Risk Assessment of Chemicals (ILMERAC), FDA’s largest global coalition. This group supports the development of new risk assessment methods for chemicals in food. It includes food regulators from around the world working on NAMs.

Through partnerships, training, and harmonization, HFP aims to build stakeholder confidence, overcome hurdles, and integrate NAMs into regulatory frameworks globally.

The International Liaison Group on Methods for Risk Assessment of Chemicals (ILMERAC) is a network of more than 25 governmental and intergovernmental organizations active in the field of food and feed safety at the global level. ILMERAC was founded in 2018 under the auspices of the European Food Safety Agency. Hosting of the Scientific Secretariat of ILMERAC rotates among the member organizations; from 2024–2026, the Scientific Secretariat is hosted by the German Federal Institute for Risk Assessment. FDA is a member of ILMERAC, with the primary participants being scientists within the FDA Human Foods Program. Current ILMERAC focus topics include NAMs, next-generation risk assessment, and toxicity of mixtures and per- and polyfluoroalkyl substances.

In 2024 and 2025, ILMERAC held three general meetings in person and online, two scientific web meetings, and three online Expert Dialogue meetings on the topics of “Use of AI in Risk Assessment,” “Use of MPS in Chemical Risk Assessment,” and “Data Integration.” The ILMERAC Annual Meeting in October 2025 focused on “The Probable Future of Risk Assessment.”

In 2023, NIH approved the Complement Animal Research in Experimentation (Complement-ARIE) program concept to accelerate the development, validation, and adoption of NAMs, especially those that combine different approaches to more accurately model human biology and diseases. Complement-ARIE is an NIH-wide effort, involving 23 Institutes, Centers, and Offices, and was developed with input from eight federal agencies. U.S. federal agencies participating in Complement-ARIE activities include:

• U.S. Department of Health and Human Services
  • Advanced Research Project Agency-Health
  • Biomedical Advanced Research and Development Authority
  • National Institutes of Health
• Defense Threat Reduction Agency (U.S. Department of War)
• U.S. Environmental Protection Agency
• U.S. Food and Drug Administration
• National Aeronautics and Space Administration
• National Institute of Standards and Technology
• U.S. Department of Agriculture
• U.S. Department of Veterans Affairs

In 2025, EPA and FDA formalized their participation in Complement-ARIE through Memoranda of Understanding. Activities that will be facilitated and conducted under these agreements include providing regulatory expertise from EPA and FDA to support, refine, and advance Complement-ARIE projects, and the convening of joint workshops to support progress and develop new initiatives. A number of governmental, international governmental, nongovernmental organizations, and private companies are participating in the Complement-ARIE Validation and Qualification Network, a public-private-partnership managed by the Foundation for NIH to accelerate the regulatory approval and deployment of NAMs for biomedical research. The network includes 20 public partners, with representatives from the European Union, United Kingdom, and Japan, as well as over 40 private sector partners. Partner organizations provide scientific and regulatory expertise to develop projects within the Complement-ARIE Validation and Qualification Network.