Observational Retro-prospective Study on PD1/PDL1 Inhibitors Treatment Duration in Patients With NSCLC

Programmed cell Death protein / Ligand 1 (PD-1 / PD-L1) inhibitors Atezolizumab, Nivolumab and Pembrolizumab have demonstrated a great efficacy and a good safety profile in patients with Non-Small Cell Lung Cancer (NSCLC), both in first-line (PD-L1 expression \> 50%) and in subsequent lines regardless of PD-L1 status. Recently, the combination of Pembrolizumab with platinum salts and pemetrexed has become the gold standard for the first-line treatment in patients with PD-L1 expression \<50%. Data on the optimal duration of immunotherapy are scarce, especially considering that the onset of immune-related adverse events (irAE) has also been reported after several months of treatment and the long-term effects of the persistent immune system stimulation are unknown. Furthermore, predictive factors are not available to identify those patients who will respond to treatment and could benefit from a shorter duration of therapy -this information is pivotal to minimize the risk of side effects and improve the quality of life. Basal characteristics, such as PD-L1 expression, percentage of Cluster of Differentiation 8 (CD-8) + T-lymphocyte in tumor-infiltrating lymphocytes (TILs), mutational status, neutrophil to lymphocyte ratio (NLR), and platelets to lymphocytes ratio (PLR) have been reported as possible biomarkers, but further data are needed to confirm their predictive value. The purpose of the study is to identify the differences in terms of effectiveness and safety of immunotherapy in long-responder patients in the two cohorts. Secondary objectives are to evaluate the outcome after anti-PD1/PD-L1 rechallenge or other treatment for patients who progress after immunotherapy discontinuation and to identify baseline characteristics that may be predictive of response (molecular characteristics, biohumoral parameters, body mass index).