Multidisciplinary approach to immune related adverse events as a potential biomarker: Single institution experience in non-small cell lung cancer.

Abstract

e14124 Background: Immune checkpoint inhibitor (ICI) has emerged as a novel systemic treatment for advanced cancers. As ICI modulates immune signaling pathways by targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1) or its ligands (PD-L1), a number of immune related adverse events (IRAE) have been reported. Whether IRAE can be a predictor for treatment response has remained controversial and we evaluated the association between IRAE and outcome. Methods: Retrospective chart and Computed Tomography (CT) review of patients with stage IV NSCLC treated with single agent Nivolumab or Pembrolizumab was performed. Any abnormalities in lab values, imaging finding or clinical signs to suggest pneumonitis, thyroiditis, hepatitis, nephritis, pancreatitis, colitis, pleural/pericardial effusion, arthritis or myositis between the start of the therapy and six months after the end of the therapy were recorded in a binary fashion. Abnormality in the setting of baseline abnormal values or due to clear cause other than IRAE has been excluded. Overall survival as well as best response based on RECIST 1.1 was also recorded. Results: 88 patients treated between January 2012 and March 2017 were identified. 62 patients, 42 patients and 50 patients demonstrated abnormalities in lab values, CT and clinical signs, respectively. When each subcategory was correlated with OS using ANOVA, thyroid function test abnormality (n = 15) and liver function test abnormality (n = 36) were associated with increased OS (p = 0.021, p = 0.038, respectively). Interestingly, elevated C-reactive protein was associated with decreased OS (p = 0.01). Initially, each score was given depending upon the number of abnormal categories (lab, imaging or clinical signs), ranging from score 0 (n = 7), 1 (n = 19), 2 (n = 33) and 3 (n = 17). Increased score was associated with increased OS (p = 0.03). For more detailed analysis, we came up with scoring system which sums up each score given for any abnormality in each subcategory. On Multivariate analysis, there was significant positive correlation between higher score and increased OS (p = 0.001). Conclusions: We have identified several IRAE parameters that were associated with increased OS. Furthermore, scoring system used in the study which encompassed clinical, radiologic and laboratory aspect, showed positive association with increased OS, indicating IRAE’s potential role as a biomarker.