The US Food and Drug Administration (FDA) has published draft guidance outlining regulatory considerations for the submission and postapproval management of individualized human genome editing products intended to prevent, treat or cure monogenic diseases.

The document describes how multiple patient-specific product variants may be included in a single Biologics License Application (BLA) under section 351(a) of the Public Health Service Act. It introduces the concept of the Individualized Feature Space (IFS), which defines the allowable limits of variation in genome editing components while maintaining the product’s core design and intended editing outcome.

The guidance explains how sponsors may add new product variants within an established IFS after approval, potentially using in vitro activity and safety data without conducting separate clinical studies for every variant, where scientifically justified. It also addresses manufacturing process design and validation, potency assurance, off-target editing assessment, postapproval change management, product labelling and variant identification.

The document is intended for developers and manufacturers of individualized genome editing therapies, regulatory affairs professionals and specialists in chemistry, manufacturing and controls (CMC) and quality assurance.

Publisher: US Food and Drug Administration (FDA), Center for Biologics Evaluation and Research (CBER).
Document type: Draft Guidance for Industry.
Publication date: October 2026.
Status: Draft — Not for Implementation.