Leveraging Prior Knowledge in the Development of Human Gene Therapy Products Incorporating Genome Editing

Issue Date: June 2, 2026
Issued by: Center for Biologics Evaluation and Research,Office of Therapeutic Products
Topic(s): Gene Therapy
Status: Draft

Leveraging Prior Knowledge in the Development of Human Gene Therapy Products Incorporating Genome Editing

We, the FDA, are issuing this draft guidance to assist you (manufacturers, applicants, and other stakeholders) in developing human gene therapy (GT) products incorporating ex-vivo and in vivo genome editing (GE) of human somatic cells (GE products). Specifically, this guidance reflects FDA’s current thinking on the type of prior knowledge (i.e., public and platform knowledge) that may be scientifically appropriate to leverage to advance product development. This guidance also provides recommendations on how sponsors may consider leveraging prior knowledge to increase review efficiency and accelerate product development across multiple programs. These recommendations include how to leverage chemistry, manufacturing, and controls (CMC); nonclinical; and clinical prior knowledge. The ability to leverage prior knowledge to expedite product development may be particularly helpful in the context of GE products intended to treat rare diseases, many of which may be serious and life threatening.

Download the Guidance Document