Once the phase I and II studies yields results that further warrant the clinical evaluation of the product, the production process needs to be characterized at small scale prior to process validation for phase III clinical trials. Currently there are very few CDMOs that provide process characterization services, let alone for LBPs. Typically the small scale process characterization is initiated once the decision has been made to start planning the phase III clinical trials.
The objective of process characterization is to determine the Critical Quality Attributes (CQAs) of the Drug Product, and the impact that the Critical Process Parameters (CPPs) have on the CQAs. Process characterization is a fair amount of work, but will lead to the determination of a Design Space, i.e. a set of process parameters that always leads to a Drug Product that passes all QC testing criteria. During Process Validation, the CQAs and CPPs are confirmed at the commercial manufacturing scale. Both the process characterization and process validation in combination with the stability data are the most important parts of the CMC section of a BLA submission.