FDA: New Drugs Don't Need Animal Testing Before Human Trials

Pharmaceutical companies will no longer be required to test new or developing drugs on animals before giving them to people in human trials, according to a new law that was passed by Congress and signed by President Biden in December.

The law, which is officially called the FDA Modernization Act 2.0, will give companies the ability to use different testing methods, such as computer models and cell-based assessments, instead of animal testing when they are making new drug submissions.

In a statement, Sen. Rand Paul, R-KY, said that the “inclusion of this bipartisan effort is a step toward ending the needless suffering and death of animal test subjects,” and “will accelerate innovation and get safer, more effective drugs to market more quickly by cutting red tape that is not supported by current science.”

The nonprofit organization People for the Ethical Treatment of Animals (PETA) called the new law a “radical shift” in how new drugs and treatments will be developed. In a statement, the organization wrote that the FDA “will be allowed to consider superior, non-animal tests. It’s a change that mirrors a request that PETA scientists made of the FDA in 2020.”

Here’s what else you need to know about the new law, including which other testing options companies may choose to use to determine if new drugs are safe enough for human clinical trials. 

New Technology Means Animal Testing Is Not Always Necessary

Aliasger Salem, PhD, a professor of Pharmaceutical Sciences and Experimental Therapeutics at the University of Iowa’s College of Pharmacy, told Verywell that one reason the change is happening now is that previous legislation did not take new testing methods that have been developed in recent years into consideration, since they didn’t exist at the time.

“There is always merit in revisiting the rules and regulations as technologies and methodologies emerge so that the rules that are in place take into consideration the current status of our environment for technology and methods,” said Salem.

Kathy Guillermo, PETA Senior Vice President, told Verywell that animal studies and tests do not provide full proof that drugs would be effective and safe in humans.

“Tests on animals fail to yield marketable medications,” said Guillermo. “An astounding 95% of all new medications that test safe and effective in animals go on to fail in human clinical trials.”

How Will Companies Test Drugs Without Animals?

According to the FDA Modernization Act, alternatives that drugmakers can use to assess new medications and treatments include cell-based assays, 3D-printed “organ chips,” microphysical systems, sophisticated computer modeling, and other human biology-based test methods.

Alternative testing strategies like cell-based assays are already being used to analyze the effects of toxic chemical substances on healthy and diseased cells (what’s called in vitro toxicity data).

Other options are organ chips and microphysical systems, which use human cells and engineered structures to create an environment that copies or models the function of specific organs to test drug efficacy in diverse human populations.

A recent application of the method was in COVID-19 drug and vaccine testing. It’s been able to give researchers a better understanding of how the SARS-CoV-2 virus interacts with human organs and prompts an immune response.

“This is a positive step in the direction of continuing the development of strategies and technologies that can help to develop drugs in a safe and effective way,” said Salem. “These kinds of technologies that exist now can help with the replacement, reduction, and refinement of animal use.” 

However, Salem noted that the challenge with these alternative technologies is that they are still in development and more research is needed to verify that they could be viable options to replace animal testing. 

Animal Alternatives Have Limitations

Salem added that companies that are looking to switch to alternative strategies for evaluating drug effectiveness and safety must be aware of the limitations of those methods and “need to have a high degree of confidence and certainty that these new systems will capture the full range of toxicities,” such as liver failure, organ failure, inflammation, or cardiac toxicity like a heart attack.

An FDA spokesperson told Verywell that the agency will continue to support the best available scientific methods to ensure clinical trials of drugs are safely conducted in humans. Drug companies will also need to provide sufficient data to support the safety of their proposed clinical investigations and drug proposals. 

Can Drug Companies Still Test On Animals?

While the new law gives pharmaceutical companies the ability to use different testing methods to make drug submissions to the FDA, it does not eliminate animal testing. Companies will still have the option to test drugs on animals if they choose to.

The National Association for Biomedical Research—which supports testing drugs in animals—believes that animal testing is the most adequate way to determine the effectiveness of drugs before they reach human trials. 

In a statement, the organization said that “animal testing followed by human clinical trials currently remains the best way to examine complex physiological, neuroanatomical, reproductive, developmental and cognitive effects of drugs to determine if they are safe and effective for market approval.”

While the FDA stated that the new law reduces animal testing through the development of qualified alternative methods, the agency also highlighted that there are still many areas where animal research is scientifically necessary, like in “highly complex interacting [body] systems.”

Without the use of animals, the FDA stated that it would be impossible to gain some of the important knowledge needed to prevent suffering from many life-threatening diseases in humans and animals.

For instance, animal research has played an important role in advancements such as preventing polio, eradicating smallpox, and identifying new cancer treatments.

“We understand and share the concern that animals should only be involved in research when there is no other way to fulfill an important public health objective,” the FDA spokesperson said. “When these studies are scientifically necessary, the animals involved in research require care under strict, human guidelines.”

Keeping Safety Top of Mind

Elizabeth Unni, PhD, MBA, BPharm, chair and associate professor of Social, Behavioral, and Administrative Sciences at the Touro College of Pharmacy, told Verywell that unless there is data to show that alternative testing methods can safely and effectively replace animal testing, pharmaceutical companies should be using them.

“In the long run, if these testing methods prove to be efficacious and safe, they can result in less time for drug approval and lower cost to the pharmaceutical companies,” said Unni.

Whatever testing methods companies end up choosing, Salem believes that it should be “the most appropriate model for the drug that they are developing.”

“Any company developing a drug has a responsibility to use the most appropriate method that is established and has clearly defined parameters for determining safety and efficacy,” said Salem. “And so the method that a company chooses for the development of that drug should be the guiding principle.”