1041P Efficacy and safety of chemotherapy after progression on immunotherapy: Results of a multicenter retrospective observational trial

Abstract

Limited evidence is to date available about the efficacy and safety of chemotherapy after progression on previous immunotherapy in metastatic NSCLC patients. We retrospectively collected data on consecutive, stage IIIB-IV, ECOG performance status (PS) 0-2, NSCLC patients treated with single agent or combination chemotherapy after progression on a previous immunotherapy regimen. Baseline characteristics, outcome measures and toxicities were recorded. An exploratory analysis on the predictive value of the neutrophil-to-lymphocyte (N/L) ratio was performed. One-hundred patients were included in the analysis. Median age was 67 (range 39-81) years, M/F 66%/34%, ECOG PS 0/1/≥2 47%/51%/2%, adeno/squamous carcinoma 77%/23%, with median of 50% (range 0-100) PD-L1 expression. Previous immunotherapy consisted on a single agent treatment in 83% of cases with a prevalence of pembrolizumab use with a median pre-chemotherapy N/L ratio of 4. Overall median time-to-progression on previous immunotherapy was 6 months while it raised to 7.5 months in cases receiving single agent. Only 33% of cases received chemotherapy after immunotherapy. Platinum doublets (mostly carboplatin) were delivered in 31% while single agent chemotherapy in 69% of cases (vinorelbine 25%, taxanes 25%, gemcitabine 8%) with a median of 4 (range 1-16) cycles delivered. Overall response rate was 21% with a median clinical benefit of 55%. Median time to progression was 4 (range 1-17) months and median overall survival was 5 (range 1-22) months. Comparison of low vs high N/L ratio subgroups did not show any significant difference in terms of survival. A minority of advanced NSCLC patients received chemotherapy after immunotherapy. Chemotherapy showed modest clinical efficacy after progression on immunotherapy while no safety issues were recorded. Baseline N/L ratio failed to predict chemotherapy benefit after immunotherapy.