Real-world outcomes of immunotherapy-based regimens in first-line advanced non-small cell lung cancer

Background: First-line (1L) immunotherapy (I-O) has improved outcomes in patients with advanced non-small cell lung cancer (NSCLC) in clinical trials and is now routinely used alone or combined with chemotherapy. Although efficacy and safety of I-O therapies have been established in clinical trials, little is known about their performance and long-term efficacy in the real-world setting. We aimed to characterize real-world outcomes for patients with advanced NSCLC treated with 1L I-O therapy in the United States. Methods: Patients aged >18 years with confirmed advanced (stage III-IV) NSCLC who received either 1L I-O monotherapy or single-agent I-O combined with chemotherapy on or after January 1, 2016 were identified from the Flatiron Health database. Primary objectives were to examine overall survival (OS) and real-world progression-free survival. Index date was defined as date of 1L treatment initiation; data cut-off date was June 30, 2020. Results: Among 4271 patients receiving I-O plus chemotherapy, median OS was 10.6 (95 % confidence interval [CI], 9.3-11.8) months in patients with squamous NSCLC (n=814) and 12.0 (95 % CI, 11.3-12.8) months in those with non-squamous disease (n=3457). Regardless of histology, patients with high (>50 %) tumor programmed death ligand 1 (PD-L1) expression demonstrated longer median OS vs those with low expression. Among 3041 patients receiving I-O monotherapy, median OS was 11.3 (95 % CI, 9.8-12.8) months in patients with squamous NSCLC (n=875) and 14.1 (95 % CI, 12.4-15.8) months in those with non-squamous disease (n=2166). OS benefit appeared to be greatest in the >50 % tumor PD-L1 expression group of the non-squamous cohort. Conclusion: Survival estimates were generally lower than those reported in pivotal clinical trials. These findings indicate that there remains room for improvement of real-world survival outcomes in patients with advanced NSCLC who receive 1L I-O-based regimens and for identification of subgroups of patients not benefitting from treatment with current I-O regimens.