Quality control of biological raw materials to ensure the viral safety of cell and gene therapy products.

Most cell and gene therapy (CGT) products use human- or animal-derived raw materials during manufacturing. The viral safety of the final products must be ensured from the point of use of the biological raw materials. Cell therapy products, which involve living cells as the final product, are vulnerable to heat and chemicals and cannot be filtered. Therefore, it is not possible to establish a process for removing and inactivating viruses and microorganisms from these products, as is performed for biopharmaceuticals. Ensuring the viral safety of the final product requires rigorous control of the contamination risks posed by biological raw materials, which are considered more critical than those encountered in conventional biopharmaceutical manufacturing. Based on the consultation and review of CGT products by the Pharmaceuticals and Medical Devices Agency, we evaluated frequent issues and described the points to be considered regarding the quality control of biological raw materials used in the manufacturing of CGT products.