For certain monospecific antibodies, three-month toxicology studies plus other supportive evidence will suffice, eliminating the need for six-month testing.
The FDA is planning to scale back or outright eliminate testing on non-human primates for certain antibody therapies, continuing the agency’s campaign to move away from animal experiments.
In a draft guidance released Tuesday, the regulator said that for monospecific antibodies—those that target just one epitope—three-month toxicity studies in non-rodent models will suffice, removing the need for six-month experimentation. Drugmakers will need to supplement these, however, with other safety evidence, such as pharmacologic and mechanism-of-action data or findings of assays and toxicology studies.
Additionally, data from other antibody agents against the same target could also help companies build their case, the FDA said. In cases where there is “substantial animal data” from these similar antibodies, “no toxicology studies are warranted,” according to the draft guidance—not even the shortened three-month studies.
Despite easing its animal testing rules, the FDA still maintained several quality considerations for non-clinical safety data. Toxicology studies in animals should always be conducted in “pharmacologically relevant species” and clearly demonstrate that the antibody binds to its intended molecular target, as well as elicit its expected phenotypical effect.
In a statement on Tuesday, FDA Commissioner Marty Makary said that these new guidelines are part of the agency’s “commitment to eliminate animal testing requirements in drug evaluation,” an effort that he added will “accelerate cures and meaningful treatments for Americans.”
In April, the FDA announced plans to phase out animal testing for monoclonal antibodies, instead replacing them with “more effective, human-relevant methods.” The agency was specifically referring to artificial intelligence-based models designed to assess drug toxicity, as well as computer simulations that “could simulate how a monoclonal antibody distributes through the human body.”
The regulator at the time also pointed to the use of human organoids in the lab, as well as organ-on-a-chip systems that can help assess the effects of therapies on human tissues.
The announcement has divided the industry. Organoid manufacturers and animal rights advocates have welcomed this move. “There’s a place for animals in drug discovery, but animal research shouldn’t be the go-to,” Tomasz Kostrzewski, chief scientific officer of CN Bio, which makes organ-on-a-chip systems, told BioSpace in May.
Other experts caution that the alternatives to animal testing aren’t yet advanced enough to be reliable measures of safety. “There are certain aspects of living systems that we can’t model yet,” Joseph Wu, Stanford Medicine cardiologist and co-founder of Greenstone Biosciences, which supports drug discovery efforts by providing stem cells and organoids.
