Recent early stage clinical trials evaluating the adoptive transfer of patient CD8(+) T-cells re-directed with
antigen receptors recognizing
tumors have shown very encouraging results. These reports provide strong support for further development of the therapeutic concept as a curative
cancer treatment. In this respect combining the adoptive transfer of
tumor-specific T-cells with
therapies that increase their anti-
tumor capacity is viewed as a promising strategy to improve treatment outcome. The ex vivo genetic engineering step that underlies T-cell re-direction offers a unique angle to combine
antigen receptor delivery with the targeting of cell-intrinsic pathways that restrict T-cell effector functions. Recent progress in genome editing technologies such as
protein- and
RNA-guided
endonucleases raise the possibility of disrupting gene expression in T-cells in order to enhance effector functions or to bypass
tumor immune suppression. This approach would avoid the systemic administration of compounds that disrupt immune homeostasis, potentially avoiding autoimmune adverse effects, and could improve the efficacy of T-cell based adoptive
therapies.