71P Correlation between toxicities and outcomes during treatment with immune checkpoint inhibitors in non-small cell lung cancer patients

Abstract Background Immunotherapy of cancer has changed the paradigm of treatment of many tumours, especially non-small cell lung cancer (NSCLC). The use of immune-checkpoint inhibitors (ICI) is associated in some patients with the development of new immune-related adverse effects (ir-AEs). Our aim was to study if there is any correlation between the appearence of ir-AEs and the efficacy of ICI. Methods We collected data of 66 patients diagnosed of advanced NSCLC and treated with ICI in monotherapy at our institution between December 2015 and May 2019. Several variables as clinical, tumour-related and therapeutical were included and univariate and multivariate Cox regression analysis were performed. Results Cohort of 50 men and 16 women, median age of 67 years and 80% with Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1. 66% were active or ex-smokers and 34% had never smoked. 62% of patients had adenocarcinoma histology, 32% scamous and 3% had not otherwise specified (NOS) carcinoma histology. 3% of patients had III-B stage at the moment of start of immunotherapy, 36% M1a, 35% M1b and 24% M1c. 2 patients had driver mutations in EGFR gene. 53% of patients had unknown PDL1 status; 9% had no PDL1 expression, 9% low expression and 27% high expression. 82% of patients had progressed to prior line of treatment, while 18% were treatment-naive. irAEs occured in 55% of patients; 11% developed grade 3 to 4 toxicities. More frequent irAEs were fatigue (61%) and rash (32%). Significant statistical variables in univariate analysis were included in multivariate analysis by Cox regression. The appearence of any grade of toxicity was associated with improved progression-free survival (PFS) (median 5.2 months vs 2.7 months; HR 3.53; p = 0.018; 95% CI [1.24-10.07] ). The use of corticosteroids during treatment with ICI was not related to PFS. Conclusion Appearance of immune-related adverse effects during treatment with ICI was associated with better outcomes in our population. The use of corticosteroids during immunotherapy didnt have any deleterious effect on the efficacy of treatment. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.