ICCVAM Biennial Report 2024-2025

Although new approach methodologies (NAMs) are being increasingly developed and used, their adoption for regulatory decisions has been slow, and awareness outside certain scientific communities remains limited. To address this, the ICCVAM Consideration of Alternative Methods Workgroup gathered input from stakeholders in industries such as agrochemicals, consumer products, and pharmaceuticals as well as from academic researchers and animal care committees.

The review (Oyetade et al. 2025) found that while all stakeholders use or consider NAMs, adoption levels vary. Five key barriers were identified: perception, regulatory acceptance, scientific and technical limitations, education, and financial challenges. Stakeholders highlighted the need for clear regulatory criteria, better awareness of NAM capabilities, and resources for education and funding as critical points for improvement.

To overcome these barriers, several solutions were proposed. These include tailored education programs to inform diverse audiences, proactive collaboration across sectors, harmonized national and international standards for NAM acceptance, and the creation of centralized repositories, such as the Collection of Alternative Methods for Regulatory Application (CAMERA), for NAM-related information. Other recommendations involve increasing awareness of NAM strengths and limitations and ensuring NAMs are used in ways that suit specific purposes.

This effort provides a roadmap for advancing NAM adoption, emphasizing the importance of communication, education, and collaboration. By addressing these challenges, the use of NAMs can expand, supporting ethical and scientifically robust methods for chemical testing and regulatory decisions.

When making regulatory decisions about the safety of chemicals found in foods, the FDA Human Foods Program (HFP) values, among others, (1) high-quality data; (2) a thorough, unbiased, and transparent scientific review process that considers dietary exposure; and (3) confidence in tools and methods used to assess chemicals of interest. When it comes to NAMs, HFP evaluates the applicability, limitations, biological relevance, reliability, reproducibility, and sensitivity (collectively known as performance standards) of each NAM to determine whether it provides the information it was designed to provide when used under the conditions for which it was intended. This approach is closely aligned with the ICCVAM vision for the implementation of NAMs. 

To facilitate the development of NAMs for assessment of toxicity of chemicals and contaminants in the U.S. food supply, HFP followed ICCVAM guidance documents to establish a pilot program called Engaging NAMs for Toxicant Regulation and Effects (ENTRÉE). The ENTRÉE pilot program provides a roadmap to partner with ICCVAM and identify NAMs by delineating data and information of importance to HFP. The initial focus of the pilot program is to establish a relationship with ICCVAM and other external entities and to foster the development of NAMs for use by the HFP to support food chemical hazard identification, screening, risk assessment, and risk prioritization.

Formal approaches to method validation, as described by ICCVAM, involve lengthy and expensive processes. However, a NAM may not need to undergo every step in a validation process to yield valuable data depending on the method’s context of use. In these instances, the process HFP ENTRÉE uses to evaluate a NAM for regulatory use is called “qualification.” The HFP works to ensure NAMs are appropriately evaluated, whether validated or qualified, for regulatory use. Qualification involves establishing scientific rigor by which a NAM must be judged based on its intended context of use. Within a specific context of use, a designation of “qualified” means that the HFP has concluded that the results of an assessment using the NAM is reliable regarding a specific interpretation and application in product development and regulatory decision-making. Qualification also identifies the limitations of the predictive value of the NAM. Once the HFP qualifies a NAM, the FDA can be confident in both the predictive value of the method and its results, and it can be used by industry and other interested parties for its intended purpose.

The HFP believes working with ICCVAM and other interested parties to advance the development and qualification of NAMs can help ensure the safety of the food supply and result in more predictive human-relevant models. HFP plans to evaluate at least four or five NAMs through the ENTRÉE pilot program in the next year. Test method sponsors interested in participating should contact FDA at [email protected]. The partnership between ICCVAM and HFP will allow for the reduction, refinement, and replacement of the use of animals for assessing the safety of chemicals found in foods.

Since the 1940s, human predictive patch tests (HPPTs) have been used to study chemicals that can cause skin sensitization, which occurs when the immune system overreacts to certain substances after skin exposure. These tests involve applying a chemical to healthy volunteers to observe reactions. Using a previously compiled database of 2,277 HPPT results for 1,366 unique chemicals (Strickland et al. 2024), scientists from CPSC, FDA, NICEATM, and the German Federal Institute of Risk Assessment conducted an analysis (Herzler et al. 2024) focused on how HPPT data can help classify chemicals as skin sensitizers under the United Nations Globally Harmonized System for Classification and Labelling of Chemicals. They suggested that the standard dose per skin area metric could be refined to include improved descriptors, such as the dose per skin area that causes sensitization in one person or 5% of tested individuals. These new measures could provide more accurate assessments of the risks posed by chemicals.

While HPPT data alone are not always enough for clear classifications, their use in combination with data from other sources, such as the local lymph node assay, improves assessment accuracy. The study also introduced standardized workflows for analyzing individual HPPT results, combining multiple results, and incorporating them into a broader weight-of-evidence approach with local lymph node assay data. Overall, this research demonstrates that while HPPT data have limitations, their use remains a valuable tool for chemical classification when combined with other methods. Integration of these data into modern approaches enhances reliability and reproducibility, paving the way for safer chemical regulations and improved skin sensitization assessments.

DOI scientists at multiple USGS science centers continue to advance ecotoxicity testing and biomonitoring methods that reduce reliance on animals in environmental assessments. This work emphasizes NAMs that provide innovative, nonanimal tools for understanding how emerging contaminants affect fish and wildlife health. State and federal agencies are already applying these findings in decision-making and environmental management. Collectively, these efforts demonstrate practical applications of in vitro, in silico, and noninvasive tools that support ecological decisions and minimize animal handling, disturbance, and stress.

• USGS is currently conducting research on stressor–response relationships in aquatic species, including studies of stormwater-derived toxicants, such as 6PPD-quinone (a tire wear transformation product), and the evaluation of alternative compounds with reduced toxicological impact. Pacific salmon (Onchorychus spp.) cell line assays allow rapid, mechanistic screening of potential 6PPD substitutes. These assays reduce the need for animal models and can provide detailed insights into immune, metabolic, and cellular pathways affected by tire wear chemicals. Complementary efforts support the development of Bigg’s killer whale (Orcinus orca rectipinnus) cell lines as surrogate in vitro systems for assessing risks posed by persistent organic pollutants to endangered Orca populations. Together, these NAM-based approaches strengthen DOI’s capacity to deliver decision-relevant science for species conservation and ecosystem health under the One Health paradigm.
• USGS and EPA are jointly conducting a multiphase transcriptomic zinc toxicity study using zebrafish (Danio rerio) and medaka (Oryzias latipes). Through iterative experimentation, the partnership is generating robust mechanistic datasets that improve EPA’s metals assessment processes and advance USGS’s function to develop modern mechanistic tools for ecological toxicology.
• USGS scientists are also participating in an international ring test aimed at standardizing the zebrafish dark/light transition test, a widely used locomotor assay for detecting subtle neurobehavioral effects of chemical exposure. Because laboratories currently employ diverse protocols, exposure conditions, and analytical approaches, cross-study comparison is challenging. The ring test evaluates both technical and biological variability and develops harmonized procedures to improve reproducibility and consistency. By reducing variability and establishing standardized methods, this work directly supports ICCVAM’s goals of advancing reliable, fit-for-purpose NAMs suitable for regulatory consideration.
• From a biomonitoring standpoint, USGS researchers continue to use environmental DNA as a noninvasive method for detecting sensitive or imperiled aquatic species, such as freshwater mussels and state-listed darters, without requiring physical capture or intrusive field procedures. By enabling efficient, low-impact survey methods, environmental DNA functions as a NAM aligned with ICCVAM’s goals of reducing animal use while supporting robust ecological data collection for management and conservation decisions.

EPA considers chronic risk to birds when evaluating ecological risk to wildlife from the application of pesticides. These risk assessments are supported by ecotoxicity data required for pesticide registration, including data on avian reproductive toxicity (OCSPP 850.2300) in two bird species: an upland game species (typically bobwhite quail, Colinus virginianus) and a waterfowl species (typically mallard duck, Anas platyrhynchos). EPA is collaborating with nongovernmental organizations and industry stakeholders on a retrospective analysis to assess species differences in sensitivity to conventional pesticides, which can help determine how testing only two standard avian species influences ecological risk assessments. The analysis examines patterns in species sensitivity across chemical groups. When species differences are identified, an additional analysis will be conducted to determine if differences in species sensitivities could be reliably accounted for without testing of a second species. The goal of this project is to determine if there are factors that can be considered when determining testing requirements for conventional pesticides and if chronic risk to birds can be confidently assessed using a reduced number of test species. Results will be described in a paper projected for submission to a peer-reviewed journal in 2026.

Value-of-information analysis is a systematic approach to determine the “value of information” in economic terms. It allows comparison of “what we already know” and “what we will know” to determine which data generation methodologies are most valuable for decision-making. While the potential application of value-of-information analysis in toxicology has been discussed for several years, practical applications of such an analysis to real-world toxicological problems are lacking.

EPA and collaborators developed a value-of-information framework for assessing the trade-offs associated with uncertainty, duration, and cost of chemical toxicity testing (Hagiwara et al. 2023). A novel feature of this framework is the inclusion of a time dimension that permits incorporation of the cost of delay in additional information. A case study applied this framework to compare a short-term in vivo transcriptomic assay approach for the development of protective reference doses with the traditional chronic rodent bioassay and human health assessment process. The analysis found that the transcriptomic assay was the preferred testing method in the majority of scenarios considered. The analysis evaluated various combinations of exposure conditions, health endpoints, exposure control costs, population characteristics, and decision types using a range of values informed by real-world data. The value-of-information analysis results indicated that reducing the time to decision, realized by using the shorter-duration transcriptomic assay, has significant public health and economic benefits when compared to longer traditional toxicity testing and the human health assessment process. The final case study was published in 2024.

FDA provides a Catalog of Regulatory Science Tools to Help Assess New Medical Devices. This peer-reviewed resource assists medical device companies in evaluating new medical devices in contexts where standards and qualified medical device development tools do not yet exist. The catalog collates a variety of regulatory science tools developed by the FDA's Center for Devices and Radiological Health's Office of Science and Engineering Labs. The tools use the most innovative science to support medical device development and patient access to safe and effective medical devices. Tools categories include laboratory methods, computer models, and data sets, and they are applicable to program areas including cardiovascular, neurology, and biocompatibility and toxicology. The catalog was updated in 2024.

FDA HFP has a long-standing commitment to promote the development and use of new technologies to predict and evaluate the safety of regulated products. HFP has a broad research program aimed at developing NAMs for regulatory use. HFP has identified several top priorities for NAMs development, including:

• Development and evaluation of new in vitro and in silico approaches for food safety applications, including the highly anticipated release of the Expanded Decision Tree in 2025
• Identification of NAMs approaches applicable to endpoints, including developmental neurotoxicity, vascular cardiotoxicity, and hepatotoxicity, with emphasis on relevance to chronic dietary exposure
• Use of NAMs to explore the intersection of diet and the gut microbiome with human disease
• Facilitation of research through internal, external, and international partnerships

Qualification of NAMs for HFP applications will emphasize biological relevance and technical characterization. Biological relevance assures that the NAM identifies, measures, or predicts the in vivo event of interest and accounts for relevant pharmacokinetics and exposure estimates. Appropriate technical characterization ensures that the NAM will yield reproducible results and be cost-effective for users. The goal is to support broad use of NAMs that support improved human health.

In 2020, FDA launched the Innovative Science and Technology Approaches for New Drugs (ISTAND) program to support the development of innovative tools that can improve drug development and regulatory decisions. ISTAND focuses on qualifying cutting-edge technologies including super intelligence (SI)-based algorithms; novel advanced testing methods, including NAMs such as microphysiological systems (MPS) that reduce reliance on animals; and digital health tools, such as wearables. As of 2025, ISTAND has transitioned from a pilot program to a permanent part of the FDA’s Drug Development Tools Qualification Program.

The ISTAND qualification process involves three steps: submitting a Letter of Intent, a Qualification Plan, and a Full Qualification Package. Accepted tools and their status are made public, ensuring transparency as required by the 21st Century Cures Act. Once a tool is qualified, it can be used in regulatory submissions without requiring further re-evaluation for its qualified context of use.

Since its launch, ISTAND has accepted several innovative tools, including SI-based tools, methods for assessing safety without using animals, and technologies involving human tissues, into the program. These tools provide modern, science-driven approaches to support drug safety and effectiveness evaluations.

ISTAND complements other FDA initiatives aimed at accelerating drug development while reducing the need for animal models. By promoting and qualifying innovative approaches, ISTAND plays a crucial role in advancing drug development and fostering regulatory acceptance of modern scientific methods.

Animal testing has long played a central role in drug development, but animal studies often fail to accurately predict how safe or effective a drug will be in humans. They also increase the cost and time it takes to bring new treatments to patients. To address these issues, the FDA and NIH are focusing on new approaches that rely on advanced computer modeling, super intelligence, and laboratory techniques using human cells or organ-like systems.

A New England Journal of Medicine AI 2025 Policy Corner article by FDA and NIH scientists highlights scientific and regulatory momentum toward shifting from traditional animal models to these innovative human-based alternatives (Scheufen Tieghi et al. 2025). These methods have the potential to improve the safety and effectiveness of drugs while reducing costs and accelerating the discovery process. Several real-world examples show how alternative testing methods are already being used in regulatory decisions, providing evidence that these approaches are both feasible and effective. Successfully integrating these new methods into drug approval processes requires continued public awareness, collaboration with the pharmaceutical industry, and increased transparency in research. Mapping out milestones and addressing challenges, such as validating the accuracy of these methods and updating regulatory policies, will be critical for the widespread adoption of alternatives. By prioritizing these predictive technologies, regulatory agencies aim to modernize drug development, making it faster, safer, and more cost-effective, ultimately improving patient access to life-changing treatments.

NAMs include tools such as advanced computer models (in silico), complex 3D cell models (in vitro), and other specialized technologies such as cell-free systems, digital twins, and MPS. Over the past 15 years, NIH has significantly increased investment in these methods, recognizing their ability to enhance research while complementing traditional animal models.

In 2024, NIH approved the Complement Animal Research in Experimentation (Complement-ARIE) program to accelerate the development, validation, and adoption of NAMs, especially those that combine different approaches to more accurately model human biology and diseases (Sunderic et al. 2025). The program focuses on four key goals:

1. Using NAMs to complement traditional animal models, making research more effective
2. Validating mature NAMs to gain regulatory approval for widespread use
3. Modeling human health differences across populations, including personalized insights
4. Developing innovative methods to study specific biological processes or disease states

To inform its strategy, the NIH conducted strategic planning activities, including an interagency retreat, public listening sessions, and scientific analyses, along with the organization of an innovation challenge prize. These efforts helped identify key opportunities and address challenges related to the implementation of NAMs, such as improving standardization and overcoming operational roadblocks.

The Complement-ARIE “Ideation” Challenge Prize competition, announced in late 2023 as part of the strategic plan, offered $1,000,000 in total prize money to multidisciplinary teams with ideas for new ways of using NAMs. Twenty winning teams each received $50,000 to develop new ways to use NAMs, which NIH used to understand gap areas, innovative spaces, and areas of greatest need that could be addressed by the Complement-ARIE program.

In April 2025, Complement-ARIE launched its Validation and Qualification Network to accelerate regulatory approval and deployment of NAMs for biomedical research. The Validation and Qualification Network will work with regulatory authorities from other federal agencies, industry partners, and other collaborators to establish and apply validation/qualification frameworks to NAMs. These frameworks will prepare newly developed NAMs to more easily enter validation pipelines and regulatory review, paving the way for NAMs use on a broader scale by researchers in industry and biomedical research. In August 2025, the Foundation for NIH invited developers to submit NAMs for initial assessment by the Validation and Qualification Network.

In September 2025, Complement-ARIE issued the NAMs Reduction to Practice Challenge Prize competition. This open competition, with $7,000,000 in total prize money, tasks innovators with accelerating the technological development of near-ready integrated NAMs platforms and translating their products into practice. Top-scoring submissions will be delivered to the Validation and Qualification Network for validation and qualification.