Chimeric antigen receptor T cells (CAR T) have emerged as a hugely promising therapy for the treatment of hematological malignancies. A number of CAR T products are now approved for the treatment of relapsed/refractory diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, B-acute lymphoblastic leukemia and multiple myeloma. Predicting treatment responses and toxicity such as cytokine release syndrome and neurotoxicity remains an important goal. As such, there is increasing interest in tracking CAR T expansion post infusion through flow cytometry, with a view to increasing our understanding of treatment responses and improving management of patients.
The CAR T staining reagents and gating strategies we use to detect and quantify CAR T post-infusion will be discussed. This includes preliminary data for detecting the recently approved CAR-19 Breyanzi and a BCMA-CAR. We will also consider some features of assay design that will support the development of clinical CAR T detection assays.