WASHINGTON, D.C. – The United States is set to reduce its reliance on monkeys for drug-safety testing, marking one of the most significant shifts in federal research policy in decades.
The Food and Drug Administration (FDA) on Tuesday released draft guidance eliminating the long-standing requirement for six-month repeat-dose toxicity tests in monkeys for monoclonal antibody drugs.
These therapies — lab-engineered proteins widely used for cancer, autoimmune diseases and other chronic conditions — have historically involved extensive primate testing before reaching human trials.
Instead, the FDA says that emerging technologies such as advanced computer modelling, lab-grown mini-organs, and tightly controlled human studies can now provide equivalent or better safety data.
“We are delivering on our roadmap commitment to eliminate animal testing requirements in drug evaluation and our promise to accelerate cures and meaningful treatments for Americans,” said FDA Commissioner Marty Makary.
The agency noted that a typical nonclinical programme for monoclonal antibodies could involve more than 100 macaque monkeys, even though primate tests often fail to translate into human-approved medicines. Apes are no longer used for invasive research in the United States.
Animal advocates welcome the move
The decision was welcomed across animal-rights circles, which have long campaigned for a transition away from primates in research.
Zaher Nahle, a former animal researcher and now senior scientific advisor at the Center for a Humane Economy, described the move as an “important step.”
“These primates are not reliable in terms of predicting toxicity,” he said, adding that non-animal approaches can achieve “equal or better” accuracy.
Research shows that more than 90 percent of drugs deemed safe in animals ultimately fail to win human approval.
Justin Goodman of the White Coat Waste Project said the update “moves us one step closer to wiping out the federal government’s wasteful monkey business,” noting that federal agencies are already pulling back from primate testing.
A recent Science report revealed that the Centers for Disease Control and Prevention (CDC) plans to close its primate labs.
Despite the shift, the National Institutes of Health (NIH) remains the largest user of primates in federal facilities, with at least 7,700 monkeys currently housed in its labs and breeding centres, according to public data cited by advocacy groups.
Researchers warn against a rush to eliminate animal tests
Some scientists, however, cautioned that the move should not be interpreted as a green light to end all animal research.
Deborah Fuller, director of the Washington National Primate Research Center, said the FDA’s move on monoclonal antibodies was “very reasonable” because non-animal methods are already well suited for that specific category of toxicity testing.
But she warned that scaling back too broadly could threaten medical innovation.
“This needs to be driven by science and data, not ideology,” she told AFP. “In terms of the next cures and biomedical advances, we still need animals.”
Animal research, supporters argue, has played a critical role in breakthroughs such as vaccines for diphtheria, yellow fever, measles and Covid-19.
Meanwhile, critics contend that entrenched laws, journal publication incentives and a lucrative “animal-industrial complex” have made it difficult for newer, non-animal technologies to gain traction — even as their reliability improves.
The FDA’s draft guidance will undergo a public comment period before it is finalized.
