In December 2022, the FDA Modernization Act 2.0 was passed by Congress as part of the FY2023 Omnibus bill. The FDA Modernization Act updated the Federal Food, Drug, and Cosmetics Act (FFDCA) by lifting the requirement for animal testing and allowing applicants for market approval for a new drug to use the best methods available other than animal testing to establish the drug’s safety and efficacy. These methods include human-relevant organ chips, computer modeling, and organoids.

When the FDA Modernization Act passed, there were many articles discussing how the FDA no longer requires animal testing, but this is not necessarily the case. While the Act is a great step forward for transforming the drug development pipeline, it does not address the development of medical countermeasures (MCMs). MCMs are “FDA-regulated products that may be used in the event of a potential public health emergency.” When discussing animal testing at the FDA, the issues surrounding MCMs are often left out of the conversation.

MCMs can be biologics, drugs, and medical devices that, in some cases, involve bioterror threats. When testing MCMs, there are certain situations that cannot use human efficacy studies because of ethical concerns for humans. The Animal Rule allows animals to be used rather than human testing for situations in which definitive human efficacy studies cannot be conducted because it would be unethical to deliberately expose human volunteers to toxic biological, chemical, radiological, or nuclear substance and does not apply to substances that can be approved based on efficacy standards through other FDA regulations.

The Animal Rule is largely considered “a step forward in addressing the fact that the efficacy of countermeasures against most biothreat agents cannot be tested in humans because it is unethical for humans to be given the disease against which the countermeasures are intended.” Ignoring how it is also unethical to give non-human animals these diseases—this is the perfect opportunity for the FDA to make use of and support human-relevant research methods. Relying on ineffective animal tests for MCMs creates an additional efficacy hurdle. A 2011 study conducted by the National Research Council’s (NRC) Standing Committee on Biodefense for the Department of Defense agrees: “experience since its promulgation demonstrated that it is not a facile pathway for assessing the efficacy of a countermeasure in humans based on the product’s efficacy in animals.”

Both the NRC’s report and past research show that despite biological similarities between humans and other animals, subtle nuances in physiology, biochemistry, and genetic expression are misleading drug development. Complex models based in human biology can benefit the development of MCMs since they more faithfully recapitulate human physiology as compared to animal tests and have the potential to predict human safety much more accurately.

Under the FDA Modernization Act, there is nothing that states animal testing will no longer be allowed or is no longer acceptable. The FDA Modernization Act allows in certain situations where there are alternatives such as organ chips or organoids to be used instead of animals, but does not state that animals cannot be used for testing. This support of human-based alternatives should be expanded to testing for MCMs. In order for an MCM to receive grant approval under the Animal Rule, a drug or biologic product must be shown to likely produce a clinical benefit in humans.

So while the FDA Modernization Act may be a great start for changing the future of medical research and drug development, there is still work that needs to be done to fully embrace what human-relevant alternatives have to offer. This is work that the Center for Contemporary Sciences is focused on advancing. To contribute to this effort, consider donating monthly in support of our mission to significantly––and ethically––advance human health.