The U.S. House of Representatives passed the FDA Modernization Act 3.0 this week, and lawmakers and animal welfare advocates are celebrating the bill as a step toward a new era in preclinical testing and drug development.
The FDA Modernization Act (FDMA) 3.0 would require the FDA to update regulations that still refer to animal testing when federal law permits the use of alternative nonclinical testing methods. “The House passage of the FDA Modernization Act 3.0 marks a major step toward a more modern, effective, and humane system for evaluating medicines,” bill sponsor Rep. Buddy Carter, R-Ga., said in a July 20 release.
The legislation follows the FDA Modernization Act 2.0, which passed in 2022 and removed a longstanding statutory requirement that investigational drugs undergo animal testing before being studied in humans. The law allowed drug developers to use scientifically valid nonanimal methods, but FDA regulations had not fully caught up. Version 3.0 directs the agency to update its rules to reflect the change in federal law.
In 2025, the FDA released a roadmap to guide the shift away from animal testing requirements, and the agency marked the plan’s first year of progress in April. The roadmap says the FDA aims within three to five years to make animal studies the exception, rather than the norm, in preclinical safety and toxicity testing.
The agency has also launched initiatives to encourage the adoption of new approach methodologies, or NAMs, as alternatives to animal testing. The FDA created a searchable table identifying drug development contexts in which NAMs may be accepted, qualified an artificial intelligence tool for evaluating liver biopsy images and issued draft guidance aimed at reducing primate testing of monoclonal antibodies. The agency has also said it will consider NAM data that have not previously been qualified for a specific context of use.
In December, the U.S. Senate passed a nearly identical bipartisan bill led by Sens. Cory Booker, D-N.J., and Eric Schmitt, R-Mo. After the House passed its version this week, the Senate must approve the House-passed bill before it can be sent to President Donald Trump for his signature.
“With the imminent enactment of the FDA Modernization Act 3.0, we can as a nation embrace scientifically superior methods that can speed the development of safer medicines, reduce costs, and spare countless animals from counterproductive testing on them,” said Wayne Pacelle, president of the Center for a Humane Economy and Animal Wellness Action, in a statement.
Recent FDA draft guidance says the regulator will consider data from NAMs such as organoids and organs-on-chips even when the methods have not previously been qualified by the agency, potentially accelerating the use of alternatives to animal testing. But experts are split on how much impact the guidance, released in March, will ultimately have.
Vanda Pharmaceuticals said in a March press release that the guidance lacked a clear example of an accepted NAM that fully replaces an animal test and included scant scientific references, unclear authorship and “vague validation requirements.”
Meanwhile, the National Institutes of Health has awarded more than $150 million through the Complement Animal Research In Experimentation (Complement-ARIE) program. The awards followed the NIH’s previously announced $87 million initiative for organoid development and the creation of an office to lead the agency’s development and use of NAMs.
A March release described seven new technology development centers “designed to stimulate the development of NAMs to address areas of greatest both scientific and regulatory need, with emphasis on biological complexity, throughput and data sharing.”
Although implementation of the updated regulations will take time, supporters applauded the bill as a way to align federal rules with advances in science. Zaher Nahle, Ph.D., senior scientific adviser for the Center for a Humane Economy, said these nonanimal techniques had “greater predictive value than traditional animal models in many areas of biomedical research.”
“Removing outdated animal testing mandates from federal law can help get drug treatments to patients faster,” said Rep. Nanette Barragán, D-Calif., the lead Democratic co-sponsor of the legislation. “The FDA Modernization Act 3.0 helps ensure federal implementation keeps up with modern scientific innovation and the growing availability of human-relevant research methods.”