FDA says it will phase out animal testing requirement for monoclonal antibodies and drugs

By Jen Christensen, CNN

(CNN) — The US Food and Drug Administration announced Thursday that it will be phasing out a requirement that monoclonal antibodies and other drugs be tested on animals, saying in a news release that there are “more effective, human-relevant methods” to test drugs.

To get FDA approval, scientists must be able to demonstrate that a new drug or treatment is safe and effective. And currently, before they can test a new therapy in humans, they must show proof that it worked in a lab and often that it works in animals.

For decades, animals have been a key to biomedical research because although they are physically different from humans, many are biologically similar enough and get the same diseases as humans. Animals were often thought to be good stand-ins for humans at a point in a clinical trial when it could otherwise be too dangerous.

Animals have an advantage in the lab because scientists can completely control the environment in which they live during the experiments. Animals also typically have shorter lives than humans, so a therapy could be studied over an animal’s entire lifetime and even over generations with its offspring.

The bipartisan FDA Modernization Act 2.0, which became law in 2022, paved the way for the latest step at the FDA.

The bill amended the Federal Food, Drug, and Cosmetic Act to remove a requirement that sponsors of new drugs use animal studies to get licensure from the agency, allowing them to use animal testing alternatives instead.

Thursday’s FDA announcement said that “the new approach is designed to improve drug safety and accelerate the evaluation process, while reducing animal experimentation, lowering research and development (R&D) costs, and ultimately drug prices.”

“The FDA’s animal testing requirement will be reduced, refined, or potentially replaced using a range of approaches,” the agency said, including AI-based computational models about how toxic a medicine is. Scientists could also use humanoid models and real-world human data in support of their application.

“This initiative marks a paradigm shift in drug evaluation and holds promise to accelerate cures and meaningful treatments for Americans while reducing animal use,” FDA Commissioner Marty Makary said in the release.

The FDA said it would work to update its guidelines, incentivizing companies that submit strong safety data from non-animal tests by potentially offering them a streamlined review.

The change has been a long time coming, said Dr. Paul Locke, a professor in the Department of Environmental Health and Engineering at Johns Hopkins Bloomberg School of Public Health.

“It’s really nice to see FDA make this step in the right direction along a road that’s going to really improve public health and get us much better medicines much more quickly with using fewer resources,” he said.

Animal models have been helpful to scientists but sometimes have more limited success than scientists would like, he said.

“Nonhuman animals are not humans, so they have different biology, different ways of processing chemicals and other differences, and we miss things, and we can overestimate things when we use them,” Locke said.

Locke, who is also a lawyer who specializes in animal law, said he has spoken over the years with drug developers and academics who have been frustrated by the need for animal studies.

Technology, they have told him, has advanced enough with AI and with the development of organoids – small cells that organize into something approximating a human organ – that they are good alternatives for testing novel therapies, but the FDA wouldn’t accept that data.

Locke said it is clear from Thursday’s announcement that the FDA’s approach to this change will be gradual, but “it is starting down an important road of transitioning away from animals.”

“It’s really an important step,” he said. “They are going in the right direction.”

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