Quality by Design in analytical development for cell therapies: using the analytical target profile to meet ICH Q14 expectations

The recent introduction of ICH Q14, together with the revised ICH Q2(R2) guidelines, redefines analytical development and replaces traditional validation with a science- and risk-based lifecycle approach. It underscores the critical value of analytical design and development, emphasizing the establishment of an Analytical Target Profile, applying Quality by Design principles, and continuously monitoring method performance to ensure reliability across the product lifecycle.

In alignment with this framework, we have developed one unified flow cytometry-based analytical model featuring two complementary analysis strategies – one for identification and one for impurity detection a – for the phenotypic characterization of cell therapy products. The method illustrates the development of a flow cytometry characterization approach, within the potentially applicable regulations for cellular products, and is illustrated with two cell types commonly used for therapeutic purposes: T cells and mesenchymal stromal cells. It enables precise assessment of cell identity and purity through the selection of specific surface markers and predefined acceptance criteria specified in the ATP. This development-phase confirmed specificity, precision, and accuracy, while robustness was evaluated based on structured risk assessment to identify critical analytical procedure parameters.

This work illustrates how the application of ICH Q14 and Q2(R2) principles can guide the development of scientifically sound and regulatory-compliant analytical methods. The proposed approach provides a methodology for cell phenotyping that may be extended to other cell therapy products, contributing to consistency and harmonization in advanced therapy analytics.