1262P - Predictive model for survival in advanced non-small cell lung cancer (NSCLC) treated with frontline pembrolizumab

Abstract

BackgroundPembrolizumab monotherapy improved overall survival (OS), progression free survival (PFS) and response rate compared to chemotherapy in patients with treatment-naïve advanced NSCLC with high PD-L1 expression (>=50%), but we see in daily clinical practice that not all patients in this subgroup benefit equally. Prognostic and predictive factors and tools are needed. MethodsMulticentric retrospective review of advanced NSCLC patients with high PD-L1 treated with frontline pembrolizumab from March 2015 to April 2019 was performed in 19 Spanish hospitals. We analyzed the prognostic value of different clinical variables and Lung Immune Prognostic Index (LIPI), and selected those who were prognostic in the univariate analysis. Multivariate Cox regression models were adjusted to evaluate the adequacy of models, C-index was used (values over 0.7 indicate a good model, and values over 0.8 indicate a strong model. Results223 patients were included. Mean age 67 years (SD 9.8). 77.6% were male and 75% PS<=1. Predominant histologies: adenocarcinoma (65%), squamous-cell carcinoma (26%). Median PFS was 12.8 months (CI95%;9.8-15.9). Median OS was not reached (24 month-OS 53.6%). LIPI 2 subgroup (unadjusted HR 3,77;p<0,001), female sex (HR 1,76; p=0,034), age under 60 (HR 1,74; p=0,039), presence of>=2 metastatic locations (HR 2,74;p<0,001), basal haemoglobin level<=12g/dl (HR 2; p=0,005), corticoids use (HR 5,31;p<0,001) and ECOG-PS (HR 5,43;p<0,01) were included in a predictive Cox regression model, with a predictive C-index of 0.812 for OS and 0.76 for PFS, suggesting good discrimination. OS predictive model was called LIPI-FAMACE: LIPI - F(emale) A(ge) M(etastatic locations) A(nemia) C(orticoid use) E(COG). ConclusionsLIPI-FAMACE model has a good capability for predicting survival in patients with advanced NSCLC and high PD-L1 expression treated with frontline pembrolizumab. This model needs prospective validation in an independent prospective cohort. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.