Abstract
BACKGROUND
Management of advanced NSCLC has been transformed by PD-1/PD-L1 immune checkpoint inhibitors (ICI), with FDA approvals in 2015 (second-line) and 2016 (first-line). Because patients with brain metastases (BMs) were disproportionately excluded from the pioneering trials, herein we evaluated the overall survival (OS) associated with ICI in NSCLC BMs nationally.
METHODS
Patients newly-diagnosed with stage 4 NSCLC, including BMs, from 2010–2016 were identified from the National Cancer Database (comprising >70% of all newly-diagnosed cancers in the U.S.) Post-approval, median time from diagnosis to ICI was 58days, and this timepoint was selected for all landmark survival analyses (logrank test and multivariable Cox regression) and for multivariable logistic regression to identify predictors of ICI utilization.
RESULTS
50,858 patients presented with advanced NSCLC that involved the brain: representing 27.6% of all newly-diagnosed stage 4 cases. Following initial FDA approvals in 2015, ICI rates for BM patients rose from 7.2% in 2015 to 12.7% in 2016. OS for NSCLC BMs for patients diagnosed post-approval (median 6.3 months, 95%CI: 6.0–6.6) was substantially better than those diagnosed pre-approval (median 5.5 months, 95%CI: 5.4–5.7, p< 0.001) and, in fact, than those diagnosed in 2014 (median 5.9 months, 95%CI: 5.6–6.1, p=0.002). Among patients diagnosed post-approval, ICI receipt demonstrated substantially improved OS in landmark survival analyses (median 13.8 months, 95%CI: 12.2–15.1; vs. 8.5 months, 95%CI: 8.3–8.9, p< 0.001); benefits which persisted in multivariable landmark survival analyses (HR 0.83, 95%CI: 0.71–0.96, p=0.02), independent of patient characteristics, other therapies, and extracranial disease. For patients diagnosed post-approval, who reached the landmark timepoint, ICI receipt was independent of patient demographics, socioeconomic status, and hospital type—with the exception of Medicaid-insured patients, who were less likely than privately-insured patients to receive ICI (OR 0.77, 95%CI: 0.60–0.97, p=0.03).
CONCLUSIONS
Nationally, the dramatic OS benefits of ICIs for advanced NSCLC were also demonstrated for patients with BMs.