Predicting failure rates in cell therapy manufacturing: is one in a million good enough?

In autologous cell therapy, the patient’s own cells are cultured, genetically engineered and expanded outside the body in small, individual batches, bespoke to each patient, before being reintroduced into the body, for example to attack a tumour.  This therapeutic approach places new demands on the manufacturing equipment needed to deliver this product.  With traditional biologics, one scales up the liquid volume of the equipment to increase production capacity.  Such systems are relatively simple to engineer for reliability and subsequently qualify through testing.  With autologous cell products, production capacity is generally scaled up by increasing the number of manufacturing systems.  This presents new challenges for manufacturing reliability because of the large number of systems, a high total part count and resulting challenges in system qualification.  Given that reduced reliability and lost production runs are not an option in autologous cell therapy, what can therapy developers do to address this challenge?