Observed survival benefit with limited exposure of durvalumab in unresectable stage III non-small cell lung cancer at a large community-based institution.

e20539 Background: The PACIFIC trial ushered in a paradigm shift in the management of unresectable, non-metastatic non-small cell lung cancer (NSCLC), demonstrating improvement in 12,24,36-month overall survival (OS) and leading to the 2018 FDA approval for durvalumab in unresectable or locally advanced stage III NSCLC. With almost 3 years of FDA approval, we performed a retrospective analysis of patient experiences and outcomes at Levine Cancer Institute analyzing patient data to assess survival and potential points of clinical significance. Methods: Patients over the age of 18, who met criteria similar to the PACIFIC trial (i.e. unresectable or locally advanced stage III NSCLC) from February 2018 through September 2020 were analyzed. Those who were receiving active treatment at the data cutoff were excluded. Patient characteristics, prior treatment, durvalumab administration, immune-related adverse events (irAEs), and efficacy data were summarized and evaluated. OS and progression free survival (PFS) were evaluated with Kaplan Meier methods. Results: A total of 159 patients were evaluated. 40.9% were female and 59.1% were male. The median age was 67 (range 38-83 years). Of note, 86.8% of patients were white, whereas 13.2% were nonwhite. 50.3% patients experienced an irAE. The most common reasons for discontinuation of durvalumab were completion (at least 24 doses), progressive disease, or toxicity (33.3%, 30.8%, 26.4%, respectively). The median number of doses of durvalumab received was 14 (range 1-26 doses). The median PFS was 15.3 months with 12-and 24-month PFS being 54% and 41.1 %, respectively. Median OS was 42 months with 12-and 24-month OS being 78.1% and 67.8%, respectively. Our analysis compared outcomes in those who completed adjuvant durvalumab versus those who did not complete adjuvant therapy (Table). Conclusions: Data shows the best survival in those who completed durvalumab (comparable to historic values) and novel data shows a perceived survival benefit in those completing 12 doses compared to those who did not. Thus, partial treatment may provide a survival advantage. Further multivariate analysis will look for possible correlations to increased immune events and inability to complete therapy. Further investigation will delve into this cohort’s small proportion of non-white patients, evaluating for possible barriers to care that may lead to more patients being diagnosed with stage IV NSCLC.[Table: see text]