Biodistribution Studies for Genetic Therapy Products Explained by FDA
(Thursday, September 16, 2021)
Biodistribution studies are needed for gene therapy products usually early on for better interpretation of the pharmacological and toxicological effects of the product, but these can be conducted under non-GLP conditions and use animal tissues specimens combined over multiple non-clinical studies. The new ICH guidance endorsed by the FDA this week provides several commonsense measures to assure acceptable biodistribution data in support of such products. Gene therapy is a broad category of products regulated by the FDA which includes purified nucleic acid (e.g., plasmids and RNA), microorganisms (e.g., viruses, bacteria, fungi) genetically modified to express transgenes (including products that edit the host genome), and ex vivo genetically modified human cells. Non-clinical studies for such products focus on the toxicological aspects of the product, biodistribution is generally deferred for later. However, FDA would like the biodistribution studies to be done earlier. To make it easy for the sponsors, FDA is amenable to accept non-GLP studies and for combining animal tissues for multiple studies. The only expectation being that if the tissues specimen were generated, say from a GMP-compliant toxicology studies, the GLP requirements for animal handling and study conduct must apply. The guidance should be very helpful to developers of gene therapy products, and make it easier to incorporate collection and analysis of biodistribution data early in the development of the product.
Dr. Mukesh Kumar
Founder & CEO, FDAMap
Linkedin: Mukesh Kumar, PhD, RAC