FDA Releases Draft Guidance on Reducing Testing on Non-Human Primates for Monoclonal Antibodies
For Immediate Release:
December 02, 2025
Today, the U.S. Food and Drug Administration (FDA) issued draft guidance outlining specific product types for which the FDA believes six-month non-human primate toxicity testing can be eliminated or reduced.
The guidance reflects the FDA’s continued progress in modernizing nonclinical drug evaluation to make it more efficient and to reduce animal testing. In lieu of animal testing, the FDA is incorporating risk assessments that integrate human-relevant models — including computational toxicology, organoid systems, and real-world human safety data — into regulatory decision-making.
“We are delivering on our roadmap commitment to eliminate animal testing requirements in drug evaluation and our promise to accelerate cures and meaningful treatments for Americans,” said FDA Commissioner Marty Makary, M.D., M.P.H. “Modern science has given us far more effective and humane ways of evaluating drug safety than animal testing. This reform may reduce the amount of time it takes to bring a drug to market and lower research and development costs, which can translate into lower drug prices.”
A typical nonclinical program with a monoclonal antibody product could include more than 100 non-human primates (often macaque monkey species), incurring costs of approximately $50,000 per animal. Yet many products that clear toxicity testing in animals do not receive FDA approval, predominantly due to safety or efficacy issues in humans.
“By incorporating a knowledge-based risk assessment, we can make better informed decisions about drug safety while maintaining the rigorous safety standards that patients depend on,” said Richard Pazdur, M.D., Director of the Center for Drug Evaluation and Research. “Risk assessments may leverage advanced methodologies. This evolution in our approach reflects both scientific progress and our responsibility to use the most effective tools for drug evaluation.”
The draft guidance represents a significant step in implementing the agency’s roadmap to reducing animal testing in nonclinical safety studies for certain monoclonal antibodies. As outlined in the roadmap, the agency will continue to collaborate with other regulatory agencies and federal partners, including the National Institutes of Health and the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) as well as international partners, to validate and expand the use of new approach methodologies to reduce or replace animal testing across therapeutic areas.
When finalized, this guidance will supplement the FDA’s Guidance for Industry (May 2012) S6 Addendum to Preclinical Safety Evaluation of Biotechnology to Preclinical Safety Evaluation of Biotechnology-Derived Pharmaceuticals, which describes scientific flexibility, product-specific evaluation, and risk assessment in nonclinical safety evaluation.
The FDA hosted a public workshop in July 2025 to examine scientifically meaningful strategies to reduce animal testing while maintaining public safety. Sponsors, researchers, and patient advocates contributed perspectives that are helping to shape the agency’s broader policy direction.
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The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, radiation-emitting electronic products, and for regulating tobacco products.
Source: U.S. Food and Drug Administration (FDA)
