Immunothérapie dans le cancer bronchique : les inhibiteurs de Checkpoints

Immunotherapy in lung cancer has usually been extremely disappointing. Highlighting the role of checkpoint inhibitors totally relaunched this therapeutic track. Two checkpoints are the targets of these inhibitors : CTLA4 and the PD1/PDL1 axis. Drugs blocking the latter are particularly developed in lung cancer and will be more widely the subject of this review. This year was very rich in data regarding efficacy, with for the first time some results of phase III trials, in pre-treated patients, and the results of large phase II studies on substantial numbers of patients. Toxicity data of these new drugs appear to be broadly similar between drugs and usually acceptable, but with toxicity profiles poorly known by thoracic oncologists (thyroiditis, rashes, colitis, etc.). A predictive biomarker identification for effectiveness of these drugs is needed but remains to be validated. Despite the significant heterogeneity between studies concerning thresholds and the cells tested for immunohistochemistry, it seems to draw a trend that should bring to validate PDL1 as a biomarker, at least in non-squamous cell carcinoma. It's a very promising therapeutic, the approvals are coming, currently in the second line only, but the development of these drugs continues particularly in first line, as a single agent or in combination with chemotherapy or tyrosine kinase inhibitors.