FDA Guidance for Accelerating Gene Therapies for Rare Diseases

On June 2, 2026, the FDA issued a draft guidance document, Leveraging Prior Knowledge in the Development of Human Gene Therapy Products Incorporating Genome Editing, that outlines the agency’s recommendations for using publicly available information and established platform knowledge, including chemistry, manufacturing and controls (CMC) data, nonclinical study results, and clinical information in regulatory submissions for gene therapy products that use genome editing in human somatic cells.1 The guidance, which supports the development of cell and gene therapy products, is part of a broader action by the FDA, including the agency’s Plausible Mechanism Framework and the Safety Assessment of Genome Editing in Human Gene Therapy Products Using Next-Generation Sequencing, draft guidance.2

“Today’s action reflects the FDA's commitment to get safe and effective cell and gene therapies to patients faster, particularly those living with rare and life-threatening diseases who have few or no other treatment options,” said Karim Mikhail, B. Pharm., M.S., acting director of the Center for Biologics Evaluation and Research (CBER), in a press release.1 “By providing information on how companies may build on what is already known we are accelerating innovation without compromising the rigorous scientific standards that patients and the public depend on. Ultimately, this is about making sure that the promise of gene therapy reaches the patients who need it most, as quickly and safely as possible.”

What Kinds of Information Does the Agency Allow?

Sponsors must provide a scientific rationale that demonstrates that product data are applicable. The draft guidance explains the type of prior knowledge that may be used in submissions to increase review efficiency, including how to leverage CMC; nonclinical; and clinical prior knowledge.

The guidance document specifies that platform knowledge may include internal company platform knowledge, such as data generated from previous products with the same or similar manufacturing platforms; third-party platform knowledge submitted in FDA master files; generally accepted scientific knowledge in published scientific literature, regulatory guidance documents, and pharmacopeial monographs; and knowledge gained from consortium and data-sharing initiatives.3

“By outlining how sponsors can intelligently build upon existing nonclinical, clinical, and manufacturing knowledge, we can meaningfully streamline development programs and lower the cost barriers that have historically slowed access to these potentially life-changing treatments,” said Vijay Kumar M.D., acting director of the Office of Therapeutic Products in CBER, in the release.1 “Leveraging prior knowledge does not mean lowering the bar; it means raising our collective efficiency while maintaining the highest standards of safety and efficacy. For patients living with serious or rare diseases, time matters. We encourage developers to engage with this guidance because their perspectives are essential to shaping a regulatory framework that works for everyone, and most importantly, for the patients who are counting on us."

"We look forward to working closely with sponsors to help them understand how to effectively implement this guidance and leverage prior knowledge in their development programs,” added Denise Gavin, Ph.D., director of the Office of Therapeutic Products’ Office of Gene Therapy-CMC.1

The guidance is released as part of the agency’s commitment to the Prescription Drug User Fee Act VII. Some of the recommendations in the document may be applicable to adeno-associated viral vectors, nanoparticle-based gene therapies, and ex vivo-modified cell-based gene therapies that do not incorporate genome editing.

For more on FDA regulations, check out PharmTech’s Regulatory Roundup for May 2026.

References

1. FDA issues draft guidance to help accelerate cell and gene therapies for patients. FDA. Press release. June 2, 2026. https://www.fda.gov/news-events/press-announcements/fda-issues-draft-guidance-help-accelerate-cell-and-gene-therapies-patients
2. FDA. Safety Assessment of Genome Editing in Human Gene Therapy Products Using Next-Generation Sequencing. FDA. April 15, 2026. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/safety-assessment-genome-editing-human-gene-therapy-products-using-next-generation-sequencing
3. FDA. Leveraging Prior Knowledge in the Development of Human Gene Therapy Products Incorporating Genome Editing, Draft Guidance for Industry. CBER, June 2026. https://www.fda.gov/media/192810/download