THER-14. INFLUENCE OF CLINICAL PARAMETERS ON THE EFFICACY OF IMMUNE CHECKPOINT INHIBITORS IN PATIENTS WITH NON-SMALL CELL LUNG CANCER BRAIN METASTASES (NSCLCBM)

INTRODUCTION: Non-small cell lung cancer brain metastases (NSCLCBM) patients have a dismal prognosis. Immune checkpoint inhibitors (ICI) have resulted in improved outcomes in a subset of patients, although limited information exists on the impact of ICI in patients with NSCLCBM. METHODS: We reviewed 121 NSCLCBM (2012–2018) patients treated at our tertiary care center. All patients received at least 2 cycles of ICI therapy after diagnosis of NSCLCBM. Overall survival (OS) and progression-free survival (PFS) were calculated from the start of ICI therapy to date of death, progression or last follow up. Kaplan-Meier curves were used to estimate survival and were analyzed using the Wilcoxon test. RESULTS: Median age was 62 years (39–81) and median KPS was 90. Eighty-six patient received Nivolumab, 7 Atezolizumab, 25 Pembrolizumab, and 3 patients received multiple ICI over the course of their treatment for NSCLCBM. One hundred and twelve patients underwent stereotactic radiosurgery. Nine patients were treated with ICI alone and 25 patients underwent surgical resection. Median OS for the entire cohort was 558 (303–1159) days and median PFS was 220 (114–512) days. Twenty-four patients received oral steroids within the first 28 days of ICI (median prednisone equivalent dose of 27 mg). Patients on upfront steroid therapy had a median PFS of 148 days vs 301 days in patients not on upfront steroids (p-value .0095). Complete blood count at the start of ICI was available for 87 patients and neutrophil to lymphocyte ratios (NLR) were calculated. Patients with NLR at the start of ICI above 5 (n=33) had a median overall survival of 337 days compared to 558 days when NLR was below 5 (p-value .038). CONCLUSION: Use of steroids at initiation or within first 28 days of ICI therapy and NLR of greater than 5 are associated with worse outcomes in NSCLCBM treated with ICI.