Background and Importance Nivolumab, an immune checkpoint inhibitor, has shown a relationship between immune-related adverse events (irAEs) and efficacy in different studies, although these are not very consistent.

Aim and Objectives The aim was to assess the association between irAEs and the efficacy of nivolumab in adults with locally advanced or metastatic non-small-cell lung cancer (mNSCLC) after prior chemotherapy.

Material and Methods Retrospective observational study including all patients with mNSCLC who received nivolumab 3mg/kg or flat dose of 240 mg every two weeks from August 2015 to June 2022 in a second-level hospital. Data collected were demographic (age, sex) and clinical (histology, smoking habit, performance status (ECOG), line of treatment, response to previous chemotherapy and irAEs).

Overall survival (OS) and progression-free survival (PFS) analysis was performed using Kaplan-Meier. The association between irAEs and OS were analysed by Cox Regression.

Results 67 patients (88% men) with a median age at the beginning of treatment of 67 years (IQR: 59-75) were included. Histology was squamous in 40% of patients. The smoking habit was: former smokers (53%), smokers (39%) and non-smokers (8%). 52% presented an ECOG 0-1. 73% of the patients received it as a second line treatment. Disease Control Rate (DCR) was 78%.

Median OS in the irAE patient group was 12.1 months (95% CI 7.9-16.3; p<0.05) vs 4.4 months (95% CI 1.9-7.0; p<0.05) in the non-irAE patient group; hazard ratio: 0.35, 95% CI 0.2-0.6; p<0.05.The median PFS was 8.7 months (95% CI 0-41.2; p<0.05) vs 3.3 months (95% CI 1.9-4.7; p<0.05), respectively.

Subgroup analysis of the association between irAEs and OS was:

Conclusion and Relevance In this study our data suggest a relationship between irAEs and increased OS, specially endocrine and skin.

As our study was observational, other features as sex, ECOG or smoking habit that could bias results were not balanced between the study groups.

Conflict of Interest No conflict of interest