FDA Webinar: Safety Assessment of Genome Editing in Gene Therapy

Why It Matters

The guidance provides a clear regulatory framework for evaluating off‑target risks, helping developers mitigate safety concerns and streamline approval pathways for emerging genome‑editing therapies.

Key Takeaways

• FDA draft guidance outlines NGS use for genome‑editing safety assessment.
• Off‑target edits and chromosomal rearrangements must be quantitatively evaluated.
• Multiple nomination methods and human genetic variation considerations are required.
• Detailed reporting standards include read counts, coordinates, and functional annotation.
• Sponsors should engage FDA early via INTERACT or pre‑IND meetings.

Summary

The FDA released a draft guidance on safety assessment of genome editing in human gene‑therapy products using next‑generation sequencing (NGS). Building on the January 2024 guidance, it focuses on non‑clinical study design, data quality, and submission requirements for DNA, epigenetic, and RNA editors.

The guidance stresses quantitative NGS evaluation of off‑target editing, unintended on‑target outcomes, and chromosomal rearrangements. It recommends multiple nomination approaches—biochemical, cell‑based, and in‑silico—and requires consideration of human genetic variation that could affect guide‑RNA binding and editing risk.

Sponsors must report detailed information for each nominated or confirmed site, including genomic coordinates, read counts, editing frequencies, alignment mismatches, and functional annotation. Documentation of assay modifications, quality‑control metrics, raw sequencing data, and analysis scripts is mandatory for IND or BLA submissions.

By standardizing NGS‑based safety assessments, the guidance aims to reduce regulatory uncertainty and accelerate development of genome‑editing therapeutics. Early engagement with the FDA through INTERACT or pre‑IND meetings is encouraged to align study plans with agency expectations, potentially shortening time to market.

Original Description

In this video, Komudi Singh from FDA's Office of Therapeutics Products walks through key highlights of FDA's recently published draft guidance on the safety assessment of genome editing in human gene therapy products using Next Generation Sequencing (NGS).

This overview covers:

- The scope of the draft guidance and its relationship to FDA's January 2024 genome editing guidance

-Safety risks associated with off-target editing and its potential impact on cell function

-How NGS technologies can be used in nonclinical studies to assess genome editing safety

-Recommendations for on-target and off-target edit site nomination and confirmation

-Sample selection considerations for ex vivo and in vivo genome editing products

-The impact of human genetic variation on off-target editing risk

-Assessment of chromosomal rearrangement events and genomic integrity

-Guidance on submitting NGS study reports and data to the FDA

Whether you are a gene therapy developer, researcher, or regulatory professional, this video provides a valuable high-level introduction to FDA's recommendations for designing and implementing nonclinical studies using NGS to assess the safety of human genome editing products.