


The Food and Drug Administration and National Institutes of Health held a joint workshop July 7 on reducing animal testing in research, strikingly announcing that “NIH will no longer seek proposals exclusively for animal models.”
This change follows the FDA’s plan to phase out the requirement for animal testing of drugs, which marked the beginning of an overall shift away from animal research to what the new leadership refers to as “more effective, human-relevant methods.”
What this means is the FDA intends to allow new drugs to be trialed in people without prior animal tests, and that the NIH will restrict funding for the very kind of research that has led to transformative medical discoveries.
As a biomedical researcher using mouse models and other tools to better understand and treat human disease, I am deeply concerned. Eliminating animal testing will make our drug supply less safe and set us back decades in making groundbreaking biomedical discoveries.
Let’s look first at drug regulation. Identifying potential new therapies first depends heavily on knowledge gained from preclinical studies in animals. These studies form the basis of biological discovery, including assessing a drug’s relevance, safety and potential efficacy before it’s ever given to humans.
Without this critical step, discovering new drugs will be far more difficult to begin with and their effects far less predictable. Only after these initial studies do drugs move into clinical testing — involving progressively larger human cohorts across three phases before approval.
Animal models are a crucial component of biomedical research because they allow us to test unpredictable biological effects between different organs and systems within a living body.
For example, a cancer drug might successfully kill tumor cells in a dish, but in a whole organism, it could cause unexpected heart damage or trigger a harmful immune response affecting other organs. An animal test is the closest possible test of the utility and safety of any drug before it’s given to humans. If drug developers are allowed to skip this step, it will mean that, in the near future, the first living body a new drug is ever tested in will be a human body.
Researchers also use animals to understand diseases and develop completely new therapies. Laboratory mice, the most commonly used animal model, have been likened to the Rosetta Stone of immunology. Much of what we now know about the immune system has been deciphered through them.
Think of immunotherapies for cancer, immunosuppressive drugs for autoimmune conditions, or treatments for allergies and infectious diseases. None of these life-saving medicines would exist today without decades of foundational research in animal models.
Nearly half of NIH-funded grants involve animal use. So why would the world’s largest public funder of biomedical research decide to make such drastic changes? The argument is that new human-based approaches can serve as a better alternative. These include lab-grown human models, computational tools and other approaches. And these can certainly complement animal models, as my colleagues and I have long worked toward. But it is premature to treat them as viable replacements.
One of the main criticisms of animal research is that the findings don’t always translate directly to humans. That is true, but there’s little evidence that the proposed alternatives yield more reliable or predictive results.
Instead of abandoning animal research, we should focus on improving existing models to better reflect human biology.
And it’s true that some mice need improving. For example, in 2006, a new drug that acts on immune cells passed through animal testing and reached the human clinical trial phase, yet it left six healthy volunteers in a critical condition.
Researchers later realized that laboratory mice had less activated immune systems compared with adult humans, because the abnormally hygienic environment of the lab prevented proper immune growth. (Germs are actually essential in teaching the immune system how to protect us.)
Researchers confirmed that adding mice from a pet-store (living under less sterile and more natural conditions with diverse germs) to the same cages as laboratory mice helped the latter’s immune systems more closely resemble those of humans.
When researchers tested the same drug from the 2006 trial in mice with more natural immune systems, they found that the mice experienced similar inflammatory complications. More recently, researchers using such mice were also able to better understand the causes of side effects from cancer immunotherapies.
And work has been under way using these improved mice for many other studies that can advance human health.
This discovery helped launch a whole new field, in which researchers like myself are working to improve mouse models and accelerate biomedical discoveries.
After the announcement, the People for the Ethical Treatment of Animals called it a “groundbreaking move” that is “a crucial first step to modernizing science and sparing millions of animals from miserable lives and deaths in laboratories.”
But it’s possible to care for animals ethically without eliminating their scientific use. Indeed, the NIH has had animal welfare policies dating back to the beginning of the 1900s.
And for at least a decade, all grant proposals have had to include consideration of alternative approaches, scientific justification of animal use and detailed protocols to minimize their distress. Institutions’ protocols are also regularly reviewed for accreditation.
We still need animal testing to find new treatments. Take the story of one-week-old baby KJ that was in the news in May. KJ was born with a severe genetic disorder that kills nearly half of affected babies in early life. But, through extensive medical efforts, which included the use of a mouse model modified with the diseased gene portion specific to KJ, a customized therapy was developed and successfully administered within eight months.
The list of biomedical successes that used animal models spans centuries — from first defining the functions of the brain and heart, to the discovery of insulin, to the development of “miracle” cancer drugs.
Human health is a shared priority, and now more than ever, it demands meaningful collaboration between scientists and physicians, policymakers and the public to protect the research systems that have enabled medicine’s greatest breakthroughs.
To borrow the recent words of Nobel laureate Ardem Patapoutian, “Now is the time for all of us to speak up — because protecting American science means protecting our future shared prosperity.”
The FDA and NIH are welcoming public feedback on this and likely future workshops, and I urge everyone to make their voices heard.
Anis Barmada is a biomedical researcher at Yale School of Medicine, P.D. Soros Fellow, and Public Voices Fellow of The OpEd Project. His research combines animal models with human-based and computational tools to better understand and treat human disease.