New FDA guidance may speed up gene therapy development

The US Food and Drug Administration (FDA) has proposed allowing manufacturers of cell and gene therapies to make use of existing scientific and platform knowledge during product development.

On 2 June 2026, the FDA published draft guidance on the use of prior information in regulatory submissions of gene therapy products incorporating genome editing in human somatic cells. The aim of these recommendations is to expedite development and help novel treatments reach patients sooner. This is especially impactful for products intending to treat rare diseases, many of which can be serious or life-threatening.

Dr Vijay Kumar, acting director of the office of therapeutic products at the FDA's Centre for Biologics Evaluation and Research, said: 'Leveraging prior knowledge does not mean lowering the bar; it means raising our collective efficiency while maintaining the highest standards of safety and efficacy.'

The guidance defines prior knowledge as established scientific information from peer-reviewed research, clinical studies or regulatory guidance, as well as platform knowledge gained from developing similar products. Examples include repeatable manufacturing processes, analytical methods and data on dose levels or delivery systems. The FDA also noted that the guidance is not exhaustive, and that other forms of prior knowledge may be used if adequately justified. This change should help streamline the regulatory submission process by reducing repeated work.

However, prior data will not be automatically accepted as its use must be supported by sufficient detail and justification. Information relating to features largely independent of a specific product, such as analytical methods or manufacturing processes, may be easier to leverage. The FDA stated that developers should engage early with regulators to discuss their intended use of existing knowledge, and what new data they may be required to collect.

Dr Kumar said: '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.'

The draft guidance, which may be revised before being finalised, is open for public comment until 1 September 2026. Although focused on genome editing products, the FDA said some of the recommendations may also apply to other cell and gene therapies, potentially widening their impact across the field.

The proposal comes amid broader efforts by regulators to accelerate the development of gene therapies and treatments for rare diseases. Recent initiatives from both the FDA and the UK's Medicines and Healthcare products Regulatory Agency (MHRA) have aimed to reduce barriers to the development of innovative therapies. This includes the MHRA recently launching a consultation on updating the legal definition of gene therapy medicinal products to reflect advances in genome editing and synthetic biology (see BioNews 1339).