Potency monitoring of CAR T cells

The effector potency of chimeric antigen receptor (CAR) T cell therapeutic products is essential to their clinical antitumor responses, and potency monitoring is a critical quality control method for CAR T cell therapy platforms. While many in vitro assays enable high-throughput assessment of CAR T cell cytotoxicity, it has been challenging for these assays to reflect the in vivo therapeutic effect due to their nature as short-term methods that fail to recapitulate the high tumor burden environment. Here, we describe two in vitro co-culture methods to evaluate CAR T cell recursive killing potential at high tumor cell loads. In these assays, long-term cytotoxic function and proliferative capacity of CAR T cells are examined in vitro over 7 days. Further, these assays are coupled with profiling CAR T cell expansion, cytokine production and phenotypes. These methods provide a facile approach to assess CAR T cell potency and to elucidate the functional variations across different CAR T cell products.