Autologous CAR-T manufacturing, batch by batch

Commercial autologous CAR-T manufacture starts with the patient's leukapheresis product, shipped fresh or frozen to a central plant. T cells are enriched (often by CD4 and CD8 selection), activated with anti-CD3 and anti-CD28 reagents, transduced with a lentiviral vector (tisagenlecleucel, lisocabtagene, idecabtagene, ciltacabtagene, obecabtagene) or a gammaretroviral vector (axicabtagene, brexucabtagene), expanded for about a week to two weeks in bags, rocking bioreactors or closed devices, then harvested, formulated in a cryoprotectant, frozen in controlled-rate freezers and held in vapour-phase liquid nitrogen. Release requires sterility, mycoplasma and endotoxin tests, vector copy number, absence of replication-competent virus, cell count and viability, the fraction of CAR-positive cells and a potency assay, and the whole run is tracked under chain of identity so the right cells return to the right patient. Vein-to-vein time is typically three to six weeks; Kite reports a median of just over two weeks in the United States for axicabtagene.

Failure modes are specific to living products: apheresis material from heavily pretreated patients that will not expand, transduction below specification, out-of-specification viability (Novartis disclosed that a share of early commercial tisagenlecleucel batches for lymphoma fell outside the viability specification and were supplied under separate arrangements), contamination, and simply having no manufacturing slot, which limited ciltacabtagene and idecabtagene access for myeloma patients in 2022 and 2023 while Legend Biotech, Johnson and Johnson and Bristol Myers Squibb added capacity. Novartis (Morris Plains, New Jersey, and sites in Switzerland, France, Japan and Australia), Kite (El Segundo and Frederick in the United States, Hoofddorp in the Netherlands), Bristol Myers Squibb (Devens and Summit), Legend with Johnson and Johnson (Raritan and Ghent) and Autolus (Stevenage) run the licensed plants, with Lonza, Miltenyi, Cellares and others as contractors and equipment makers. Shorter processes (Novartis's T-Charge, one- to two-day manufacture), closed automated devices and point-of-care production, covered in their own records, all attack the same list of failure points.