Comments on Cell & Gene Comparability Guide

Pharmaceutical Research and Manufacturers of America says it backs the overall aim of an FDA draft guidance to support a “lifecycle approach” to management and reporting of manufacturing changes for human cellular and gene therapy (CGT) products. The trade association’s comment letter gives its perspective on CGT lifecycle management and changes necessitating a “new product” classification; CGT risk assessment; comparability studies; availability of appropriate CGT models; critical quality attributes/critical process parameters; stability testing; and comparability.

In its response, the American Society of Gene & Cell Therapy says the draft guidance “seems to rely heavily on requiring statistical references for comparability studies while acknowledging that the number of lots available to complete such studies can be minimal.” It recommends that the final guidance encompass alternative methodologies that the society suggests in its letter for demonstrating comparability, particularly in smaller-scale studies or populations. It also requests clarification on the types of meetings sponsors could use to discuss comparability with the agency.

Boehringer Ingelheim says that as written, the draft “does not encourage process improvement at any stage of development, as it describes that any changes resulting in a better product quality (safety and efficacy) may finally be considered as a different product and therefore not comparable.”

Bayer comments that the draft is well-written overall and provides “good guidance to cell and gene therapy product developers.”