Defining and demonstrating the potency of a cell or gene therapy product is one of the most technically demanding requirements in biological development. Without a structured strategy built early, gaps in the testing program framework can translate into regulatory delays, complicated validations, and setbacks in the timelines.
In this article, Alexis Rossignol addresses the core challenges of potency assay development in CGT and proposes a practical two-step strategy: establishing transgene expression evidence first, then confirming a mechanism of action-representative functional readout. A phase-appropriate roadmap, key design principles, and the regulatory expectations from FDA and EMA are covered to help scientists, CMC teams, and analytical development professionals build a potency strategy that progresses confidently from early development through to GMP-validated release.
