8. Validation of Growth-Based Rapid Microbiological Methods for Sterility Testing of Cellular and Gene Therapy Products (FDA Draft Guidance for Industry)
Human somatic cell therapy and gene therapy products are an emerging class of products that present multiple challenges to safety, purity and potency. Gene therapy products (see definition in section II.D.2), include vectors (i.e., nucleic acid, virus, or genetically modified microorganisms) that are administered directly to patients, and cells that are transduced with a vector ex-vivo prior to administration to the patient. Certain genetically modified microorganisms (e.g., bacteria and yeast), cellular therapy products, and cells transduced with a gene therapy vector present similar challenges to sterility assurance. For the purposes of this document these categories of cellular and gene therapy products are called cell-based products. Many cell-based products cannot be cryopreserved or otherwise stored without affecting viability and potency. Most cell-based products are manufactured using aseptic manipulations because they cannot undergo sterile filtration or terminal sterilization (Ref. 2). Rapid and effective testing is needed because many cell-based products have a potentially short dating period, which often necessitates administration of the final product to a patient before sterility test results are available. Because of the challenges associated with cell-based products, there is a significant need to develop, validate, and implement sterility test methods that are more rapid than the sterility test methods described in 21 CFR 610.12.