April 14, 2026 - FDA Issues Draft Guidance on Genome Editing Safety Standards to Advance Gene Therapy Development

The U.S. Food and Drug Administration today issued a draft guidance for sponsors seeking approval of human gene therapy products involving genome editing technologies. When finalized, this guidance will provide recommendations for standardized methods for comprehensively assessing the safety of genome editing therapies to bring effective treatments to patients sooner.

"Genome editing holds extraordinary promise for treating previously incurable genetic diseases, and today's announcement represents the FDA's forward approach to drive innovation and advance the development of genome editing therapies," said FDA Commissioner Marty Makary, M.D., M.P.H. "This guidance provides sponsors with clear, scientifically-grounded recommendations for evaluating off-target editing risks using state-of-the-art sequencing technologies. We are serious about moving this ball forward."

The draft guidance, issued by the Center for Biologics Evaluation and Research, supports the FDA's framework for accelerating development of individualized therapies for ultra-rare diseases launched in February. The framework revolutionizes how the FDA engages with industry and promotes a path for transformative rare disease treatments.

The "Safety Assessment of Genome Editing in Human Gene Therapy Products Using Next-Generation Sequencing " guidance provides specific recommendations on sequencing strategies, sample selection, analysis parameters, and reporting. The draft guidance builds upon the agency's January 2024 guidance on human gene therapy products incorporating genome editing and focuses specifically on the use of next-generation sequencing (NGS)-based methods to evaluate potential safety risks associated with off-target editing and loss of genome integrity. The recommendations are intended to support nonclinical studies submitted with investigational new drug (IND) applications and Biologics License Applications (BLAs). The guidance applies to both ex vivo products, where cells are edited outside the body, and in vivo products, where gene editing occurs directly in the patient's tissues.

"Next-generation sequencing not only detects off-target editing and assesses chromosomal integrity; it also requires science-based recommendations for its use. We're giving sponsors a roadmap for comprehensive safety assessment while supporting the efficient development of these promising therapies," said Chief Medical and Scientific Officer and Center for Biologics Evaluation and Research Director Vinay Prasad, M.D., M.P.H. "Our goal is to work collaboratively with the scientific community to bring safe and effective genome editing therapies to patients who need them most."

The FDA encourages sponsors to engage early in product development, even before submitting an IND application, for example through Initial Targeted Engagement for Regulatory Advice on CBER/CDER Products (INTERACT) and pre-IND meetings, to discuss their specific development strategies.

The draft guidance is available for public comment. Comments must be submitted within 90 days of publication in the Federal Register at Regulations.gov. The agency will review and consider comments received before finalizing the guidance.

###