Evaluation of Prognostic Utility of Tumor Mutation Burden for Non Small Cell Lung Cancer (NSCLC) response to Immune Checkpoint Blockade Therapy: A Single Institute Study

IMPORTANCE: The role of Tumor Mutation Burden (TMB) as a prognostic and/or predictive biomarker for Immune Checkpoint Blockade (ICB) therapy in a real-world clinical setting is still unclear. OBJECTIVE: To assess whether TMB status provided by a clinically and commercially available tumor genomic profiling (TGP) assay is associated with overall survival of Non-Small Cell Lung Cancer (NSCLC) patients treated with ICB from a single institute. DESIGN, SETTING, AND PARTICIPANTS: Outcomes and genetic testing data were collected for 188 NSCLC patients treated within the Cleveland Clinic system between August 2012 and July 2017. MAIN OUTCOMES AND MEASURES: Overall survival (OS) from time receiving ICB therapy. RESULTS: Among 188 patients with NSCLC (median age, 62 years; 49.5% female), 86 (45.7%) received ICB therapy. Patients were grouped into three categories based on the status of TMB (in mutations/Mb): high (>= 20/Mb), intermediate (>=5 to 0.8], median OS difference: 9.7 months). CONCLUSIONS AND RELEVANCE: Among patients with NSCLC from a single institute with a longitudinal database of clinical data including TGP results, exploratory analyses do not show statistical significance for the prognostic utility of TMB. These findings indicate that there is a need for more prospective data on the use of TMB status as a guide for ICB therapy in a routine care setting.