FDA Moves to Phase Out Animal Testing, Ushering in a New Era for Drug Safety.

In a transformative move for biomedical research, the U.S. Food and Drug Administration (FDA) announced on April 10 its intention to phase out the use of animals in preclinical drug safety testing. The new policy outlines a shift toward New Approach Methodologies (NAMs), aiming to “reduce, refine, or potentially replace” animal studies with advanced technologies such as organoids, organ-on-a-chip platforms, and in silico modeling tools, including machine learning algorithms.

This announcement builds on the FDA Modernization Act 2.0 passed by Congress in 2022, which removed the legal requirement for animal testing in drug development. However, while the legislation allowed for alternative testing methods, it did not mandate their use—until now.

The FDA’s new roadmap suggests a gradual transition. Within a year, some monoclonal antibody drugs—commonly used to treat cancers and autoimmune diseases—could be assessed using non-animal-based methods. Over the next three to five years, the agency aims to make animal testing the exception rather than the rule in drug safety assessments.

The plan has sparked both enthusiasm and unease among researchers and industry professionals. Many welcome the ethical and scientific benefits of moving away from animal models, which are costly, time-consuming, and often poor predictors of human responses. Approximately 90 percent of drugs that pass animal testing ultimately fail in human trials, often due to unanticipated safety or efficacy issues. Joseph Wu of Stanford University highlights that this failure rate stems from fundamental biological differences between species and the inability of animal models to reflect human diversity.

However, many scientists caution that current NAMs are not yet equipped to fully replace animal studies. A 2024 report by the FDA’s NAMs subcommittee acknowledged that existing alternative assays cannot yet comprehensively simulate the complexity of human or animal organ systems. Matthew Bailey, president of the National Association for Biomedical Research, emphasized that no current simulation can capture the full intricacies of biological systems.

Researchers like Alex Rubinsteyn of the University of North Carolina share this concern. “This could become a disaster,” he said, citing both the promise and peril of relying on underdeveloped models. While NAMs can yield fast results in certain cases—especially when the biological system is well understood—many aspects of human physiology remain too complex for current models.

Nonetheless, progress is being made. Organ-on-a-chip systems are emerging as a promising substitute for in vivo testing, particularly for well-studied organs like the liver. For instance, a liver-on-a-chip developed by Emulate, Inc. correctly predicted drug toxicity with an 87% sensitivity and 100% specificity. But modeling interactions between multiple organ systems remains a formidable challenge, as does scaling these models to reflect whole-body physiology.

Stanford’s Wu has been a key figure in developing human cell-based models using induced pluripotent stem cells (iPSCs). His research has demonstrated the ability to predict cardiotoxicity in patients treated with chemotherapy and helped identify gene targets for reducing adverse effects. While these techniques still involve some animal testing for validation, Wu sees a future where NAMs guide the majority of preclinical decisions.

Despite these promising advancements, the FDA’s roadmap faces significant hurdles. The agency’s transition plan depends on the development of open-access toxicity databases, validation protocols, and standardization across laboratories. Yet ongoing budget cuts and workforce reductions at federal institutions like the FDA and NIH threaten to undermine these efforts. The NIH has already lost $1.8 billion in grant funding under the current administration, with further cuts proposed. Additionally, crucial organ-on-a-chip projects at Harvard were recently paused, and key scientific meetings have been canceled.

These disruptions raise questions about whether the infrastructure needed to support NAMs can be sustained. Rubinsteyn warns that a lack of oversight in a rapidly shifting regulatory landscape could lead to unsafe drugs entering the market if scientific rigor is compromised.

Despite the uncertainty, the move toward NAMs represents a critical step in modernizing drug development. If implemented thoughtfully, these methods have the potential to increase efficiency, reduce costs, and minimize animal suffering. But as the FDA’s own roadmap notes, success will require “careful planning, robust science, and collaboration”—all of which may be difficult to achieve under current conditions.

Source:https://www.the-scientist.com/is-this-the-end-of-animal-testing-fda-announces-plans-to-phase-out-animals-in-drug-safety-studies-73031

This is non-financial/medical advice and made using AI so could be wrong.