Matrix approach for potency assay development of cell and gene therapy products – an AAV example
MoA-reflecting bioassays for ATMP products are inherently complex. Multiple mechanisms of action are often only partially understood, and even MoA-reflective methods can be highly variable, with limitations in dilutional linearity or stability-indicating properties. Single assays rarely capture the full spectrum of biological activity, making it necessary to combine complementary methods such as cell-based functional assays and biochemical readouts. Effective assay development requires sufficient planning, with careful consideration of method capabilities, limitations, and lot-to-lot variability. Establishing robust system suitability criteria (SSC) ensures that assays maintain their intended performance across production lots, supporting both product quality and regulatory compliance.
Applying Design of Experiments (DoE) early in development allows systematic optimization of assay conditions and helps define a robust design space, as recommended in ICH Q14 and ICH Q2(R2) draft guidance. Engaging proactively with regulatory authorities is essential to clarify validation expectations, anticipate potential challenges, and support long-term development strategy. By combining thoughtful assay design, DoE-driven optimization, and early regulatory alignment, developers can create reliable, reproducible MoA-reflecting bioassays that accelerate ATMP development while ensuring patient safety.
Presenters
Sascha Karassek, Marina Alber, and Ulrike Herbrand