Immunotherapy in Cancer: Immune Checkpoint Inhibitors; Changing Oncology Treatment Paradigm

Abstract

Immune checkpoint inhibitors that target T-cells to activate immune response against tumors have shown remarkable clinical responses emerging as new potent weapon against cancer. This therapy has led to durable responses in hard to treat tumor types with long-term remissions. The field of immune-oncology has greatly evolved in recent times primarily by our enhanced understanding of T-cell stimulation and checkpoint blockade, primarily of CTLA-4 and PD-1. Clinical responses although remarkable are, however, limited to limited pool of patients and indications. This calls for further understanding of underlying biological mechanism and function of an optimal immune response. As the immune response evolves, it is unlikely to have a single actionable biomarker to predict clinical response but rather we would need a panel of markers to guide in development of therapy. Clinically validated biomarkers would therefore be needed ultimately for optimal patient and regimen selection. Clearly, the way forward is deeper understanding of our immune system and its dynamic interaction with tumor environment. The magnitude of immune response and its regulation will have to be targeted through a combination approach to provide benefit to wide range of patients and tumor types. If done properly, there is a strong chance of turning this hope into reality.