FDA Nonclinical Testing Rule Update: Non-Animal Methods Permitted

• The FDA has issued a direct final rule clarifying that non-animal methods can be used for drug and biological product safety testing before human trials.
• This update replaces terms like 'animal tests' with 'nonclinical tests' and aligns definitions with the Food and Drug Omnibus Reform Act of 2022 (FDORA).
• The rule does not eliminate animal studies, change evidentiary standards, or impose new costs, but offers greater flexibility for drug developers.
• The FDA also launched a database with 25 examples of New Approach Methodologies (NAMs) to support their use in drug development.
• The agency is seeking public comments on the rule, with a contingency plan to revert to a standard notice-and-comment process if significant adverse feedback is received.

The regulatory change reflects considerable advancements in science and technology, which have broadened the available testing options in human drug development, now encompassing methodologies that utilize human cells, sophisticated organs-on-chips, advanced computer models, and other cutting-edge technologies.

The U.S. Food and Drug Administration recently issued a direct final rule, significantly updating its regulations concerning the safety assessment of drugs and biological products intended for human use. This pivotal FDA nonclinical testing rule update clarifies that non-animal methods are permissible for testing these products before human trials, provided they are appropriate. The regulatory change reflects considerable advancements in science and technology, which have broadened the available testing options in human drug development, now encompassing methodologies that utilize human cells, sophisticated organs-on-chips, advanced computer models, and other cutting-edge technologies.

This update specifically replaces traditional terms such as “animal tests” and “animal studies” with the more inclusive “nonclinical tests” and “nonclinical studies.” Related terminology, including “preclinical” and “in vitro,” has also been revised. The new definitions for “nonclinical test” and “nonclinical study” are aligned with the provisions of the Food and Drug Omnibus Reform Act of 2022 (FDORA). This legislative act acknowledges both innovative methods that do not involve animals and conventional animal studies as valid approaches for generating the necessary evidence to initiate human studies. Crucially, the rule removes any language that might have previously implied animal testing was the sole acceptable means of gathering safety information for regulatory decisions on products destined for human use. However, it does not eliminate or prohibit animal studies, nor does it alter existing evidentiary standards or impose new costs or requirements on drug developers.

This regulatory shift is part of a broader initiative to foster innovation in drug safety non-animal testing. Acting FDA Commissioner of Food and Drugs, Kyle Diamantas, J.D., emphasized that the new rule supports the Trump Administration's objective to explore alternatives that can either complement or, where suitable, replace animal studies with methods that offer improved predictability of how medicines will affect people. The Commissioner highlighted that this provides scientists and drug developers with enhanced flexibility to select the most appropriate testing approach for their specific scientific questions. The overarching goal is not to substitute one rigid approach with another, but rather to champion rigorous, modern science, which includes utilizing animal studies when they remain appropriate and validated alternatives when they can furnish the necessary evidence to safeguard patients.

To further demonstrate the practical application of these new approaches, the FDA has also launched a dedicated database showcasing specific uses of New Approach Methodologies (NAMs). The initial release of this resource features 25 examples derived from publicly available FDA review materials. Both the new rule and the database are integral components of several actions being undertaken by the Department of Health and Human Services (HHS), including the FDA, to advance drug development through the adoption of NAMs. These innovative testing methods are designed to better reflect human biology, allowing developers to generate safety information when the methods are adequately validated and appropriate for the product and the specific regulatory inquiry.

The FDA's actions, including this FDA nonclinical testing rule update, are in line with Pillar 1 — Innovation and Global Leadership — of the agency’s Public Health Pillars. By formally recognizing a wider spectrum of scientific approaches, the FDA is keeping pace with emerging technologies and reinforcing its leadership in regulatory science. The encouragement of NAMs also complements Operation TrialBlazer, an HHS initiative aimed at modernizing clinical research and accelerating the development of life-saving treatments. The introduction of clearer terminology and regulatory expectations is anticipated to reduce avoidable uncertainty for sponsors as they develop nonclinical evidence and prepare applications to commence clinical trials.

The agency is actively soliciting public comments on the rule from a diverse range of stakeholders, including clinicians, parents, caregivers, the scientific community, and industry. For comprehensive details, interested parties can consult the Federal Register notices announcing the direct final rule, its companion proposed rule, and the associated comment period. The simultaneous publication of both the direct final rule and a companion proposed rule ensures that the rulemaking process can proceed efficiently under either scenario. Should the FDA receive significant adverse comments on the direct final rule, the agency will withdraw it and continue the rulemaking process through the standard notice-and-comment procedure using the companion proposed rule. For media inquiries, contact 202-690-6343, and for consumer information, call 888-INFO-FDA.

Source: Original reporting via FDA press release