The U.S. Food and Drug Administration today issued a draft guidance to reduce unnecessary animal testing in nonclinical safety assessments for certain cancer drugs, streamlining the path from discovery to human clinical trials.

“This draft guidance not only supports the FDA’s commitment to expedite regulatory pathways for meaningful treatments but also fulfills the agency’s promise to reduce the use of animal testing during drug development,” said Angelo de Claro, M.D., Director of the FDA’s Oncology Center of Excellence. “With recommendations for eliminating unnecessary animal testing, using a single relevant species instead of two, or replacing animal studies with evidence-based approaches — as outlined in this draft guidance — the FDA is advancing a more efficient drug development process.”

What the Guidance Proposes

When finalized, the guidance titled “Oncology Pharmaceuticals: Streamlined Nonclinical Safety Studies for Biologics and Conjugated Products” will provide recommendations for general toxicology studies. It identifies circumstances where animal testing may be unnecessary because there is no binding or pharmacologic activity. In other cases, the guidance recommends using rodent-only studies instead of requiring both rodent and non-rodent species. It also suggests replacing three-month non-human primate studies with a weight-of-evidence risk assessment, which may include New Approach Methodologies (NAMs) as appropriate. New Approach Methodologies were defined in a recent FDA webpage, marking a formal step toward integrating modern, non-animal methods into regulatory decision-making.

Building on Lessons from COVID-19

The draft guidance builds on FDA data analysis of general toxicology studies and practices developed during the COVID-19 pandemic to reduce the use of non-human primates. It also supplements guidance issued by the International Council for Harmonisation (ICH) and existing FDA guidance on nonclinical studies for oncology therapeutic radiopharmaceuticals.

The initiative is part of the FDA’s broader work to reduce the estimated 10 to 12 years it can take to bring new drugs from discovery to patients.

Public Comment Period

The FDA requests that public comments on the draft guidance be submitted by July 30, 2026. The agency will review and consider all comments received before finalizing the guidance.

Source: FDA Press Release