Identifying highly active anti-CCR4 CAR T cells for the treatment of T-cell lymphoma.

A challenge when targeting T-cell lymphoma with chimeric antigen receptor (CAR) T-cell therapy is that target antigens are often shared between T cells and tumor cells, resulting in fratricide between CAR T cells and on-target cytotoxicity on normal T cells. CC chemokine receptor 4 (CCR4) is highly expressed in many mature T-cell malignancies, such as adult T-cell leukemia/lymphoma (ATLL) and cutaneous T-cell lymphoma (CTCL), and has a unique expression profile in normal T cells. CCR4 is predominantly expressed by type-2 and type-17 helper T cells (Th2 and Th17) and regulatory T cells (Treg), but it is rarely expressed by other T helper (Th) subsets and CD8+ cells. Although fratricide in CAR T cells is generally thought to be detrimental to anticancer functions, in this study, we demonstrated that anti-CCR4 CAR T cells specifically depleted Th2 and Tregs, while sparing CD8+ and Th1 T cells. Moreover, fratricide increased the percentage of CAR+ T cells in the final product. CCR4-CAR T cells were characterized by high transduction efficiency, robust T-cell expansion, and rapid fratricidal depletion of CCR4-positive T cells during CAR transduction and expansion. Furthermore, mogamulizumab-based CCR4-CAR T cells induced superior antitumor efficacy and long-term remission in mice engrafted with human T-cell lymphoma cells. In summary, CCR4-depleted anti-CCR4 CAR T cells are enriched in Th1 and CD8+ T cells and exhibit high antitumor efficacy against CCR4-expressing T-cell malignancies.

Advances in cancer immunotherapies.

Therapeutic modalities that engage the immune system to recognize and eliminate cancer, known as cancer immunotherapy, has emerged as a distinct pillar of cancer therapy. Among the most promising treatment approaches are therapeutic vaccines, immune checkpoint blockade, bispecific T-cell engagers (BiTEs) and adoptive cell therapies. These approaches share a common mechanism of action, which is elicitation of a T-cell-based immune response, either endogenous or engineered, against tumor antigens, but interactions between the innate immune system, particularly antigen-presenting cells, and immune effectors also underlie the efficacy of cancer immunotherapies and approaches engaging these cells are also under development. To view this SnapShot, open or download the PDF.