Since publishing roadmap last April, agency has successfully launched several key initiatives to replace animal testing with better alternatives

The U.S. Food and Drug Administration today announced it achieved its key first-year goals in the implementation of its April 2025 Roadmap to Reducing Animal Testing in Preclinical Safety Studies, marking one year of transformative action to modernize drug development through innovative, human-relevant science. 

Canva image

"One year ago, we issued an ambitious roadmap to eliminate unnecessary animal testing and replace  animal testing with more precise ways of predicting drug safety in humans," said FDA Commissioner Marty Makary, M.D., M.P.H. "In addition to ushering in more scientifically accurate way to test drugs before they are used in humans, the agency has made great strides to reduce  research and development costs, which will lower drug prices for everyday Americans" 

From a purely scientific standpoint, animals are not a great model of how well drugs perform in humans. Historically, more than 90 percent of drugs that clear animal studies do not receive FDA approval, often due to safety or efficacy issues identified in human trials. To address this gap, FDA is advancing use of new approach methodologies (NAMs)—including advanced in vitro systems, computational modeling, and human-derived platforms—that better reflect human biology and improve prediction of drug effects. 

Unlike previous guidance to industry, the FDA's 2025 roadmap strategy established specific timeframes for phasing out animal testing where equivalent or better alternatives exist. Today, the agency released a follow-up report summarizing the agency's progress in implementing the roadmap and clarifying its next steps. 

Since issuing the roadmap, the agency has:  

• Released draft guidance on the reduction or elimination of nonhuman primate testing in monoclonal antibody development.  
• Updated guidance to support a transition from horseshoe crab-derived endotoxin testing, which could spare more than one million animals per year.
• Working to reduce or eliminate animal used for FDA approval when drugs have demonstrated safety from their broad use in humans in other countries.
• Released draft guidance expanding the use of weight-of-evidence approaches to support the use of NAMs, enabling drug developers to more readily incorporate in vitro assays, computational toxicology, and other human-relevant models to generate evidence across a wider array of safety endpoints.   
• Qualified the first artificial intelligence-based drug development tool, demonstrating the utility of leveraging cutting edge in silico models to support regulatory decision-making.  
• Launched a searchable database clarifying where alternative methods are acceptable, and established close collaboration with international regulators to align strategies.  

To sustain progress, FDA has deployed key infrastructure, including a permanent pathway for qualifying innovative drug development tools, cross-center scientific reviews, and a formal partnership with the National Institutes of Health. Together, these efforts are advancing a shift toward human-relevant science as the default approach to drug evaluation. 

This transition is expected to improve prediction of drug safety, accelerate development timelines, reduce costs, and expand patient access to innovative therapies, while significantly reducing reliance on animal testing. 

FDA will continue working with partners across government, industry, and academia to expand the use of these approaches and further modernize drug development. 

###