Published on Apr 17, 2025
In line with an ongoing, bipartisan push in Congress to reduce the pharmaceutical industry’s reliance on animal testing, the Food and Drug Administration (FDA) published a roadmap on April 10 laying out policy steps to transition drugmakers to non-animal methods for testing drug function and safety.
Among these so-called New Approach Methodologies (NAMs) are computational models, such as machine learning programs that predict how the body will react to a drug, “organs-on-chips,” where tissues are grown inside microfluidic devices to mimic human organ systems, and in vitro cell assays.
To pilot the program, the FDA said it will focus on a class of therapeutic proteins called monoclonal antibodies. These drugs are already difficult to test in animals “due to interspecies differences in immune systems,” the FDA argued. And testing in animals is expensive—according to the agency, a typical monoclonal antibody development program uses 144 non-human primates (NHPs), which cost tens of thousands of dollars each, as The Capitol Forum previously reported.
The FDA pitched an aggressive timeline of three to five years for making animal studies “the exception rather than the norm for pre-clinical safety/toxicity testing.”
Scientists and lawyers told The Capitol Forum that it may take longer than that for a full industry overhaul. Still, the roadmap establishes a policy framework that many consider thoughtful and long overdue.
“I applaud the effort, and I think this is where the industry is going long-term—the timeline seems very fast,” said toxicologist Tyler Vandivort, associate director and regulatory affairs lead at UCB Pharma.
To significantly reduce the industry’s reliance on animal testing, the FDA will have to write new guidance with “industry feedback from across the spectrum” and “generate convincing data that shows that the replacement assays are as effective,” Vandivort said. “To do all of that in three to five years would be staggering.”
Paul Locke, an environmental health scientist, attorney and professor who serves on the advisory board of Johns Hopkins University’s Center for Alternatives to Animal Testing, told The Capitol Forum, “I don’t think that this implementation strategy says that animal tests are going to go away tomorrow, in three years or in five years […] it’s evolutionary. It says we’re going to evolve to a new culture, and here are the steps we need to do to get there.”
The FDA’s document presents a “balanced view,” said Koen Van Rompay, a scientist at the California National Primate Research Center at UC Davis who specializes in NHP models of HIV infection. “It mentions that we want to improve and refine alternative methods to evaluate vulnerable antibodies and drugs. But I think it also highlights the need to validate many of those methods.”
FDA’s roadmap builds on previous legislation. Efforts to reduce the use of animal testing for pharmaceuticals have been in the works for years, and have come from across the aisle.
In 2022, Congress signed into law the FDA Modernization Act 2.0, a bill introduced by Senators Cory Booker (D-NJ) and Rand Paul (R-KY) that authorized the use of non-animal testing methods for investigational new drugs (INDs) and removed the animal testing requirement for biologic drugs similar to products already on the market.
Earlier this year, a bipartisan group of senators introduced the FDA Modernization Act 3.0, which would require the FDA to publish a final rule implementing the previous legislation.
“Science is clearly advancing—regulatory testing, not so much,” Thomas Hartung, a toxicologist, pharmacologist and director of the Johns Hopkins Center for Alternatives to Animal Testing, told The Capitol Forum. Hartung said the FDA’s roadmap “is an enormous signal for the regulated community—the pharma companies, and in extension medical devices, food safety—everybody under control of FDA.”
In the April 10 document, the FDA said it will encourage drugmakers to submit data from alternative testing methods and will consider waiving the requirement for animal studies in some cases.
Drugmakers that shift to using NAMs may receive certain incentives, like fast-tracked meetings and reviews with the FDA, and the agency said it may “publish case studies of successful FDA approvals that minimized animal testing.”
Also according to the FDA’s roadmap, the agency will, within the next three years, begin to accept existing human data from other countries when considering a drugmaker’s IND application: “By default, it will not be necessary to submit additional human data to the FDA if the product has been approved in a different country with similar regulatory standards unless the data are felt to be insufficient by FDA reviewers.”
To facilitate such data-sharing, the agency said it will establish a database with information on drug toxicity in animals and humans from studies around the world.
The FDA plans to reduce the duration of the NHP testing required for the development of monoclonal antibodies, and then other drug categories—all while monitoring the time and money saved by this paradigm shift, according to the policy document.
“It starts with these high-knowledge areas [like monoclonal antibodies] and then it’s going to move to areas where we don’t know as much,” Locke said. “That’s really key because FDA is not backing away from the need to make sure that anything that comes to market is safe.”
It will take “careful planning, robust science, and collaboration” to begin transitioning to NAMs for drug testing, the FDA said. The agency laid out technical steps for accomplishing this goal, including identifying key research areas where NAMs should be prioritized; investing in the development of NAMs; collecting data to validate non-animal testing methods against traditional animal testing; developing regulatory guidance on the matter; and communicating openly with drugmakers.
“One area, I think, is going to be a big challenge, and that is the whole area of validation of these methods,” Locke said. “Are you going to validate methods on a case-by-case basis so that there’s not a whole bunch of carryover, so the method can’t be used a lot by others, or are you going to validate them more broadly? For example, if you’re going to validate something for liver toxicity, that is a broad validation. That question maybe can’t be answered yet, but it’s certainly something that has to be addressed.”
Vandivort agreed: “I don’t want to understate the amount of work that needs to be done just to show that the alternative methods can yield better, or even the same, quality of results.”
The FDA’s plan to move away from animal testing will play out in collaboration with a consortium of representatives from 18 federal agencies called the Interagency Coordinating Committee on the Validation of Alternative Methods, the FDA said.
The roadmap indicates that the FDA is taking a more methodical approach to “tracking information across INDs—in terms of animal use, the amount of time spent using animal methods, the number or the costs of those, the cost of toxicity testing overall in an IND, time to approval,” Charles Raver, an FDA regulatory attorney focused on drug development at Hyman, Phelps and McNamara, told The Capitol Forum. “To my knowledge, it’s the first time that they’d be trying to do that in a systematic way to then compare how animal methods compare to these new methods.”
To be sure, the implementation of the FDA’s strategy depends on funding from Congress, Locke said. “A lot of [this] is going to be in Congress’ bailiwick. They’re going to have to be the ones that say, ‘We like this. We’re going to fund this strategy. We’re going to get this train moving down the tracks.’”
Industry impacts. Some of the largest contract research organizations (CROs) took major stock hits after the FDA announced its plans to shift away from animal testing. These include Charles River Laboratories (CRL) and Inotiv (NOTV), companies that support drug developers, in part through animal testing services.
Charles River Laboratories, purportedly the largest supplier of animals for research in the world, attributed 20.5% of its $4 billion revenue in 2024 to the Research Models and Services (RMS) segment, which mainly focuses on animal research, per the company’s most recent annual filing.
The company’s Discovery and Safety Assessment (DSA) offerings, which encompass but are not limited to animal-based testing, accounted for another 60.5% of total revenue that year, Charles River said.
“Eliminating the use of animals in research may have material adverse effects on our business, results of operations, or financial condition,” Charles River stated in its most recent 10-K.
Inotiv, too, cites the phasing out of animal testing as a potential risk to business: “New technologies may be developed, validated and increasingly used in biomedical research that could reduce demand for some of our products and services,” the company said in its most recent annual filing. “For many years, groups within the scientific and research communities have attempted to develop models, methods and systems that would replace or supplement the use of living animals as test subjects in biomedical research.”
However, sources cautioned that the FDA’s roadmap will take years to implement—and some CROs have already begun investing in non-animal testing methods, likely spurred by the ratification of the FDA Modernization Act 2.0 in 2022.
“This is something that has been forthcoming for a while, and in fact, the idea of what they call the ‘Three Rs’ in toxicology—reduce, refine, and replace—is something that’s supposed to be a core tenet,” Vandivort said. “We’re always supposed to be investigating ways in which we could limit our animal usage or get rid of it entirely.”
In 2024, Charles River launched the Alternative Methods Advancement Project, which is focused on the development of non-animal testing methods. The company said it had already invested $200 million over the past four years and would invest another $300 million in the next five.
Inotiv’s executives have similarly indicated that the company is committed to developing in vitro and computational models to reduce animal use.
It’s also worth noting that non-human primates are particularly expensive and vulnerable to supply chain constraints. Moving away from them is “an enormous value proposition,” Hartung said.
“For the NHP CROs, I don’t think this is going to have a very big impact,” Koen said. “Since the resource is scarce, [CROs] are already prioritizing what they can do anyways.”
Plus, “now that you’ve got these different assays and models that people don’t really have a lot of experience with, there’s a place for the Charles Rivers and the Inotivs to come in and to be able to offer those new services,” Vandivort said.
Inotiv did not respond to a request for comment. A spokesperson for Charles River Laboratories shared the following statement with The Capitol Forum:
“Charles River has a long commitment to the replacement, reduction and refinement (3Rs) of ethical animal use for biomedical research, and has supported FDAs efforts to advance the validation and adoption of New Alternative Methods over many years. Most recently, we launched our own Alternative Methods Advancement Project (AMAP), an initiative dedicated to developing alternatives to reduce animal testing. We are continuously evaluating innovative approaches in drug development and have invested in virtual control groups and partnerships using AI technologies to reduce animal use. We look forward to continuing to work with the FDA to follow the best and latest science to ensure patient safety.”
Over time, the FDA’s plan to reduce the use of animal testing could create an opportunity for companies that make computational tools for drug discovery. Two such companies, Schrodinger (SDGR) and Recursion (RXRX), did not respond to requests for comment.
The National Association for Biomedical Research (NABR), which advocates for the use of animals in research, pointed The Capitol Forum to a statement in which NABR President Matthew Bailey said that “no AI model or simulation has yet demonstrated the ability to fully replicate all the unknowns about many full biological systems” and that “humane animal research remains indispensable.”
