CAR T cells as drugs for novel therapies (advanced therapy medicinal products)

Background Two commercial chimeric antigen receptor (CAR) T cell products, axicabtagene-ciloleucel (Yescarta (R)) and tisagenlecleucel (Kymriah (R)), are registered for the treatment of B cell neoplasia, for which an increased supply of CAR T cell products is required. Problem The production of patient-specific CAR T cells as advanced therapy medicinal products (ATMPs) poses considerable challenges with respect to logistics, regulation, and manufacturing. Method Review of the CAR T cell manufacturing process and the regulatory network, the current challenges, and future development capabilities of CAR T cells for adoptive immunotherapy. Results CAR T cells are manufactured under individualized, laborious, good manufacturing practice-conforming processes in decentralized or in specialized centers. Starting from the patient's leukapheresis product, T cells are genetically engineered ex vivo with a CAR, amplified, and after extensive quality control re-applied to the patient. Most CAR T cell products are manufactured in a manual or semi-automated process; fully automated, supervised, and closed systems are increasingly applied to meet the need for a growing number of CAR T cell products. In this setting, research aims at providing allogeneic CAR T cell products or non-T cells such as natural killer cells for broad applications. Conclusion The significance of CAR T cells in adoptive immunotherapy is continuously growing. As individualized cell products, manufacturing requires highly efficient processes under the control of harmonized protocols and regulations so as to ensure the quality of the ATMP in view of increasing demand and to develop new fields in therapy.