Discussion

The approach to treating cancer is undergoing a revolution due to therapies based upon exploiting the potency of the immune system now delivering early clinical promise. Antibodies are leading the way with those targeting immune checkpoints delivering durable objective clinical responses in a subset of patients with advanced chemo-resistant cancer.

These approaches are largely dependent upon activation tumour specific T cells resident within the patient. However, approaches that directly use T cells are also now making a significant impact upon cancer therapy. T cells isolated from tumour biopsies (tumour infiltrating lymphocytes – TIL) and expanded to large numbers can deliver objective clinical responses in significant numbers of patients with advanced metastatic melanoma. However, tumours may not be available to isolate TILs. In this case, gene-modifying peripheral blood T cells with tumour specific T cell receptors (TCR) or antibody-type targeting chimeric antigen receptors (CAR) endows these T cells with new specificity for tumour.

Both TCR and CAR T cell approaches are delivering early clinical results. These will be discussed along with developments in T cell bioprocessing that are challenging the hurdles that currently prevent the wider exploitation of this technology.