“One question the regulators are interested in, especially the FDA, is how you characterize your product. In other words, do you know what you are putting into patients?” Mackay said. There is also concern over what effect transportation systems have on cells, and whether dead cells should be treated as contaminants and the impact of cell lysates. (Put simply, should patients be loaded with dead cells?).
“It is fundamental to characterize your product, and at an early stage,” Mackay added.
Genzyme takes the VIP (viability, identification, potency) approach to characterization with a raft of technologies for each aspect. Viability, measured by proteases, must be more than 85%; for identification, the company looks at gene expression; and for potency, rtPCR provides the necessary data. This combination, to characterize what you are actually putting into the patient, is what the regulators expect.
Furthermore, to commercialize a product it is essential to have complete traceability of everything that comes into contact with the cell.
Genzyme is tough on its products—it will dispose of any units that are in any way suspect. It also performs studies on the impact of any disturbances on the supply chain and carries out a challenge (fire drill) on its distribution cycle once a year to ensure that recovery and recall are possible in the event of a disaster. “Your product can change,” Mackay warned. “Therefore, these studies are critically important.”