B7-H3 Chimeric Antigen Receptor Redirected T Cells Target Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma

Simple Summary Although chemotherapy is associated with high relapse rates and numerous side effects, it is still used as the front line treatment of anaplastic large cell lymphoma (ALCL). Therefore, alternative treatment options for ALCL are needed. In this study, we show that B7-H3 is a novel and promising target in ALCLs, and demonstrate that B7-H3 directed chimeric antigen receptor (CAR) T cells have therapeutic potency in controlling ALCL tumor growth. Potent CAR-T therapies that target appropriate antigens can benefit the treatment of anaplastic lymphoma kinase-positive (ALK(+)) anaplastic large cell lymphoma (ALCL), which is the most common subtype of T cell lymphoma. In this study, we observed overexpression of B7-H3 in ALCL cell lines derived from clinical samples and differential expression of B7-H3 in an ALK-induced T cell transformation model. A B7-H3-redirected CAR based on scFv from mAb 376.96 was developed. B7-H3 CAR-T cells showed strong cytotoxicity and cytokine secretion against target ALCL cells (SUP-M2, SU-DHL-1, and Karpas 299) in vitro. Furthermore, the B7-H3 CAR-T cells exhibited proliferative capacity and a memory phenotype upon repeated antigen stimulation. We demonstrated that B7-H3 CAR-T cells could promptly eradicate ALCL in murine xenografts. Taken together, B7-H3 is a novel and promising target in ALCLs and B7-H3 CAR-T may be a viable treatment option for ALCL.