How Organoids and AI Are Replacing Animal Testing

As FDA & NIH formalize support for non-animal testing, organ-on-a-chip, organoids, and ML-based toxicity models are being integrated into preclinical workflows by both startups and established pharma.

On April 10th, 2025, the U.S. Food and Drug Administration (FDA) made an announcement that may reshape the landscape of medical research. In a historic policy shift, the world's leading public health regulator unveiled plans to significantly reduce—and potentially eliminate—animal testing for monoclonal antibodies and other drugs. Breaking away from decades-old practices, the FDA is adopting “New Approach Methods” (NAMs) that include AI-driven toxicity models, organ-on-chip systems, and human organoids. These models are built to more precisely replicate human physiological responses compared to traditional animal testing.

The agency plans to initially implement the strategy with respect to investigational new drugs (IND), favouring the NAMs data-rich applications for a streamlined review. Additionally, the FDA is collaborating closely with other federal agencies, starting with a focused pilot program for monoclonal antibody testing launching in the coming year.

Also earlier this month, the National Institutes of Health (NIH) mirrored FDA's step by significantly reducing grant funding for research solely dependent on animal testing. Dr. Nicole Kleinstreuer, Acting NIH Deputy Director for Program Coordination, Planning, and Strategic Initiatives, deemed this decision as necessary for public health, declaring that current objectives "cannot be fulfilled using outdated animal-based models that fail to translate to human outcomes."

Apart from increased safety testing efficacy, there is a financial incentive. A 2022 study of an organ-on-a-chip applied to test for drug-induced liver injury found it could earn more than $3B annually for the pharmaceutical industry.

But what led to this change?

In this article: Back to the Future — The Numbers Behind the Ethics — Non-Animal Realm — AI-Based Toxicity Prediction — Organ-on-a-Chip — Epilogue