LAUSR

Recent research on the relationship between the immune system and cancer has revealed the molecular mechanisms by which cancer cells co-opt certain T cell receptors which block the cytotoxic response to defend themselves from the antitumor immune attack. These findings have helped identify specific targets (T cell receptors or their corresponding ligands) for the design of monoclonal antibodies that can unlock the immune response. These drugs, known as immune checkpoint inhibitors, have shown efficacy in metastatic melanoma and kidney cancer, and have been successfully tested in non-small cell lung cancer in recent trials. Immune checkpoint inhibitors were included in clinical practice as a second-line option after an initial chemotherapy (CT) regimen, and in the last year positive results have been reported from randomized trials in which they were compared in first line with standard CT. Responses have been surprising and durable, but less than 20%-25% in unselected patients, so it is essential that factors predicting efficacy be identified. One such biomarker is PD-L1, but the different methods used to detect it have produced mixed results. This non-systematic review discusses the results of the latest trials, the possibilities of incorporating these drugs in first-line regimens, the criteria for patient selection, adverse effects, and the prospects of combinations with conventional treatment modalities, such as CT, radiation therapy, and antiangiogenic agents.