FDA is advising companies developing cell and gene therapy (CGT) products to focus on improving the characterization of products, control of the manufacturing process, and design of the related potency assays.
Better characterization, the agency maintains, will help the company understand what product attributes are truly contributing to the intended biologic effects that lead to the clinical effect. In turn, better control of the manufacturing process will lead to a more consistent product and help reduce the variability of the potency assay, which should be designed with the control of the critical reagents clearly in mind.
The opening session of the CASSS Bioassays meeting in late March in Silver Spring, Maryland focused on “overcoming the challenges” of potency tests for CGT products.
CBER Office of Cellular, Tissue and Gene Therapies Product Reviewer Xiaobin (Victor) Lu, began the session with a presentation on FDA’s expectations for the design and development of potency assays for CGTs in which he emphasized the intimate relationship between the assays and product development.
Presenting on industry experience with CGT assay development were: ● Novartis’ Erik Rutjens ● Celladon’s Barbara Thorne, and ● Ocata Therapeutics’ Irina Klimanskaya.
A panel discussion was held after the presentations to further explore the GCT bioassay challenges. The panel included the four presenters along with Health Canada’s Anthony Ridgway (see IPQ March 28, 2015 for a review of the panel discussion).