Immune checkpoint inhibitors for the treatment of glioblastoma: Where we are

Despite a history of frequent challenges and roadblocks, there has been recent excitement in the treatment of human cancer, specifically regarding the remarkable efficacy of various immune checkpoint inhibitors including programmed cell death protein 1 (PD-1), programmed cell death ligand 1 (PD-L1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) blockers in treating metastatic melanoma, non-small cell lung cancer, and other malignant growths. However, treatment of glioblastoma multiforme (GBM) with immune checkpoint inhibitors so far has not been shown to be as successful in several randomized clinical trials as in other cancer with the exception of one pilot study that found promising results by neoadjuvant administration of Pembrolizimab for the treatment of recurrent GBM. Our article will review the current status of immune checkpoint inhibitors for the treatment of GBM.