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The U.S. Senate on Dec. 16 passed the FDA Modernization Act 3.0 (S.355) by unanimous consent, sending legislation to the House that would require the FDA to update its regulations to reflect changes Congress enacted in 2022.
The bill instructs HHS, acting through the FDA commissioner, to publish an interim final rule no later than one year after enactment. The rule would replace references to “animal” tests, data, studies, models and research in specified sections of Title 21 of the Code of Federal Regulations with references to “nonclinical” tests, language that encompasses both traditional animal studies and newer methodologies.
“It has been nearly three years since Congress eliminated the legal requirement that animal testing be conducted as part of the new drug development process,” said Sen. Cory Booker (D-N.J.), the bill’s lead sponsor. “The FDA Modernization Act 3.0 will help lock in these reforms, ensuring that FDA regulations mirror current law and reflect the best available science.”
Building on FDA’s April roadmap
The legislation arrives as the FDA under Commissioner Martin Makary has already begun implementing significant changes. In April 2025, the agency announced a plan to reduce animal testing as part of a broader push to modernize nonclinical evaluation, initially focusing on monoclonal antibodies.
That FDA roadmap emphasizes New Approach Methodologies (NAMs), including AI-based computational models, organ-on-chip systems, and organoid-based testing. Commissioner Makary described the effort as a “paradigm shift,” noting that “by leveraging AI-based computational modeling, human organ model-based lab testing, and real-world human data, we can get safer treatments to patients faster and more reliably.”
The agency has also pointed to potential regulatory incentives, including streamlined review when sponsors submit robust safety packages using non-animal methods.
Broader federal signals
The Senate action arrives amid broader debate about how quickly non-animal methods can displace animal studies across different disease areas and modalities. The National Association for Biomedical Research has argued that “there is currently no full replacement for animal models in biomedical research and drug development,” even as regulators expand pathways for alternatives.
Elsewhere in the federal system, NIH has described policy shifts aimed at encouraging a wider range of approaches, including NAMs, though the agency has emphasized this does not amount to a blanket prohibition on funding proposals that use animal models.
Separately, Science reported that the CDC instructed scientists to end all monkey studies by the end of 2025—a move that would mark the first time a U.S. agency has ended its in-house nonhuman primate program since NIH retired research chimpanzees a decade ago.
Industry implications
As regulators signal greater openness to NAMs, companies across the preclinical ecosystem are expanding capabilities in human-relevant testing. Charles River Laboratories has launched its Alternative Methods Advancement Project to expand non-animal options alongside traditional services.
Market research firms project rapid growth for these technologies. Grand View Research projects the organ-on-a-chip market rising from approximately $157 million in 2024 to $952 million by 2030—a compound annual growth rate exceeding 35%. The organoid market is expected to grow from $1.4 billion in 2025 to $4 billion by 2035.
Research suggests that 90-95% of drugs that pass animal testing fail in human clinical trials, a statistic frequently cited by NAM advocates as evidence that more predictive alternatives are needed.
What’s next in the House
The House companion measure (H.R. 2821), introduced in April 2025 by Rep. Buddy Carter (R-Ga.) along with Reps. Nanette Barragán (D-Calif.) and Diana Harshbarger (R-Tenn.), has not yet advanced to a floor vote.
The legislation has attracted support from more than 200 organizations spanning animal welfare groups, patient advocacy organizations, and pharmaceutical companies including Teva Pharmaceuticals.
If enacted, S. 355 would start a one-year clock for FDA to issue the interim final rule updating its regulations to match the 2022 statutory language around nonclinical testing methods.
Filed Under: Biotech
