Addressing the complexity of process validation for cell and gene therapy products

The complexity of cell and gene therapy (CGT) products requires evolution of robust process understanding throughout the development and commercial life cycle. The expectation from health authorities on these products is that scientific and risk-based approaches will be used to define and validate the safe operating ranges for your process by identifying potential sources of variability and understanding what impact these have on product quality. However, validation is not complete once a process performance qualification (PPQ) campaign is done or once a process has been approved for commercial sale. Instead, knowledge continues to evolve throughout the life cycle of a product using the large bodies of data collected during commercial manufacturing. In the cell and gene therapy space, the FDA and the EMA have published several documents that offer guidance about early stage filings; however, these have provided limited reference to process validation and product commercialization. The expectation — just as it is with biologics — is that the process is the product. However, cell and gene therapy products have unique features that must be considered during process validation.