[Real-world study on the efficacy and prognostic predictive biomarker of patients with metastatic non-small cell lung cancer treated with programmed death-1/programmed death ligand 1 inhibitors].

To describe the actual efficacy of programmed death-1 (PD-1)/ programmed-death ligand 1 (PD-L1) inhibitors in patients with metastatic non-small cell lung cancer (NSCLC) and explore potential prognostic predictive biomarkers. Patients with metastatic NSCLC who were treated with PD-1/PD-L1 inhibitors at Cancer Hospital, Chinese Academy of Medical Sciences from January 2016 to December 2019, either as monotherapy or in combination with other agents, were consecutively enrolled into this study. We retrospectively collected the data of demographics, clinical information and pathologic assessment to evaluate the therapeutic efficacy and conduct the survival analysis. Major endpoint of our study is progression-free survival (PFS). Secondary endpoints include objective response rate (ORR), disease control rate (DCR) and overall survival (OS). The ORR of 174 patients who underwent PD-1/PD-L1 inhibitor was 28.7%, and the DCR was 79.3%. Immune-related adverse events (irAEs) occurred in 23 patients (13.2%). Brain metastasis, line of treatment, and treatment patterns were associated with the ORR of metastatic NSCLC patients who underwent immunotherapy (<0.05). After a median follow-up duration of 18.8 months, the median PFS was 10.5 months (ranged from 1.5 to 40.8 months) while the median OS was not reached. The 2-year survival rate was estimated to be 63.0%. The pathologic type was related with the PFS of metastatic NSCLC patients who underwent immunotherapy (=0.028). Sex, age, brain metastasis and autoimmune diseases were associated with OS (<0.05). Analysis of the receptor characteristic curve (ROC) of neutrophil/lymphocyte ratio (NLR) predicting ORR of immunotherapy in metastatic NSCLC showed that the areas under the curve of NLR before immunotherapy (NLR(C0)), NLR after one cycle of immunotherapy (NLR(C1)) and ΔNLR were 0.600, 0.706 and 0.628, respectively. Multivariate logistic regression analysis showed that NLR(C1) was an independent factor of the ORR of metastatic NSCLC patients who underwent immunotherapy (=0.161, 95% 0.062-0.422), and the efficacy of combination therapy was better than that of single agent (=0.395, 95% 0.174-0.896). The immunotherapy efficacy in patients without brain metastasis was better than those with metastasis (=0.291, 95% 0.095-0.887). Multivariate Cox regression analysis showed that NLR(C1) was an independent influencing factor of PFS of metastatic NSCLC patients after immunotherapy (=0.480, 95% 0.303-0.759). Sex (=0.399, 95% 0.161-0.991, =0.048), age (=0.356, 95% 0.170-0.745, =0.006) were independent influencing factors of OS of metastatic NSCLC patients after immunotherapy. PD-1/PD-L1 inhibitors are proved to be efficacious and have tolerable toxicities for patients with metastatic NSCLC. Patients at advanced age could still benefit from immunotherapy. Brain metastasis is related to compromised response. Earlier application of immunotherapy in combination with other modalities enhances the efficacy without elevating risk of irAEs. NLR(C1) is an early predictor of clinical outcome. The OS of patients younger than 75 years may be improved when treated with immunotherapy.