The US Food and Drug Administration reported progress in implementing its April 2025 roadmap to reduce animal testing in preclinical safety studies, meeting its initial 1-year milestones and advancing the use of alternative methods in drug development, according to an agency press release.
The roadmap established defined timelines to phase out animal testing when alternative approaches demonstrate equivalent or improved predictive performance. FDA Commissioner Marty Makary, MD, MPH, stated “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.”
The agency noted that animal models have historically shown limited predictive value, with more than 90% of drugs that appear safe in animal studies not receiving approval, often because of safety or efficacy concerns identified during human trials. To address this limitation, the US Food and Drug Administration (FDA) has expanded the use of new approach methodologies, including in vitro systems, computational modeling, and human-derived platforms.
Within the first year, the FDA issued draft guidance to reduce or eliminate nonhuman primate testing in monoclonal antibody development and updated recommendations to transition from horseshoe crab–derived endotoxin testing, a change projected to spare more than one million animals annually. Additional draft guidance introduced weight-of-evidence approaches to support the integration of nonanimal data sources, including computational toxicology and laboratory-based assays, across multiple safety endpoints.
The agency also qualified its first artificial intelligence–based tool for drug development and launched a searchable database to clarify where alternative methods may be used in regulatory submissions. These efforts were supported by expanded collaboration with international regulators and a formal partnership with the National Institutes of Health, along with the development of infrastructure for evaluating emerging drug development tools.
The FDA stated that continued implementation of the roadmap may improve the prediction of drug safety, shorten development timelines, and reduce reliance on animal testing.
Source: FDA