On April 10, 2025, the U.S. Food and Drug Administration (FDA) announced it will be phasing out the current requirements for animal testing in the development of monoclonal antibody therapies and other drugs, replacing them “with more effective, human-relevant methods.” According to the FDA, the “animal testing requirement will be reduced, refined, or potentially replaced using a range of approaches, including AI-based computational models of toxicity and cell lines and organoid toxicity testing in a laboratory setting (so-called New Approach Methodologies or NAMs data).”
The “human-relevant methods” promoted by the policy include both computational and laboratory-based methods. According to the FDA, advanced computer modeling and artificial intelligence can be employed to simulate drug distribution in the human body and predict side effects based on localization and drug composition. Laboratory methods that mimic human organs, such as human organoids and organ-on-a-chip systems, can be used to assess toxicity. According to the FDA, these methods both reduce the need for animal testing and provide advantages over animal models. For example, the optical transparency of organ-on-a-chip may allow for the detection of toxic effects that would otherwise go undetected in animal models.
The FDA, working with other federal agencies, such as the National Institutes of Health, the National Toxicity Program, and the Department of Veterans Affairs, will host a public workshop later this year to gather feedback and discuss a roadmap for implementation. These federal agencies will work through the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) to drive the validation and adoption of the new methods. A pilot program and accompanying study are also planned, which will give monoclonal antibody developers the opportunity to work closely with the FDA to test out the new non-animal-based methods while providing valuable data to inform future policy decisions.