Combining CAR T-cell and immune checkpoint inhibitor therapy, a promising, yet unproven immuno-oncology approach

Abstract

Chimeric antigen receptor (CAR) T-cell therapy is a method that extracts T cells from the patient's blood and virally introduces a genetically engineered T cell receptor targeting a specific cancer antigen and subsequently readministering these genetically engineered CAR T cells to the patient. These T cells are then better at identifying the tumors and attaching to these tumor cells resulting in a stronger cytotoxic immune response. The development of CAR T cells has been a huge success as an immunotherapy, especially for the targeting of non-solid tumors. Since their original inception in 1987, there are now six independent FDA approved CAR T cell therapies targeting a variety of blood cancers, with the first being approved in 2017. As a relatively new treatment, there is a continuous effort in improving the safety and efficacy of CAR T cell therapies. As mentioned previously, CAR T cells have undoubtedly been successful in the treatment of non-solid tumors, however their efficacy towards treatment of solid tumors has been limited. Additionally, the safety and long-term effects of CAR T cell treatments is still a concern. Combination therapy utilizing CAR-T cells and immune checkpoint inhibitors is being explored to potentially mitigate some of the limitations associated with CAR-T cells.