1509P - Applicability of lung immune prognostic index (LIPI) to predict efficacy of first-line pembrolizumab in advanced non-small cell lung cancer (NSCLC)

Abstract

BackgroundDerived neutrophils/(leukocytes-neutrophils) ratio (dNLR) and lactate dehydrogenase (LDH) level have been correlated with immune checkpoint inhibitors (ICI) outcomes. A lung immune prognostic index (LIPI) that showed association with ICI outcomes was developed by Mezquita L et al. based on these 2 systemic inflammation indicators (dNLR <3 and LDH > upper limit of normal (ULN)), characterizing 3 prognostic groups: good, 0 factors; intermediate, 1 factor; poor, 2 factors. This index hasn’t been specifically studied in first-line setting of NSCLC with pembrolizumab monotherapy. MethodsThis is a multicenter retrospective study to explore the prognostic value of LIPI score in treatment-naïve advanced NSCLC with high PD-L1 expression (>=50%) treated with pembrolizumab. Consecutive patients treated in 19 Spanish hospitals between March 2015 and April 2019 were included. Pretreatment LIPI score was calculated for all subjects and primary endpoint was OS. 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 number of cycles: 7 (IQR:1-33). 30.3% were LIPI 0 (good prognosis), 42.4% LIPI 1 (intermediate prognosis), and 27.3% LIPI 2 (poor prognosis). Disease control rate (DCR) was 65,6%. In Kaplan-Meier analysis, median OS for good, intermediate, and poor groups was 15,1m (95% CI, 13-17,1), 21,7m (95% CI, 18,8-24,5) and 9,3m (95% CI, 7-11,7) (p<0.001). Worse PFS was observed in LIPI2 but was not statistically significant (p=0.064). There were not OS or PFS differences between LIPI 0 and 1, but a LIPI score of 2 was independently associated with poorer OS (unadjusted HR: 3.7; 95% CI:1.89-7.5 , p<0.001); and HR adjusted by gender, sex, number of metastatic locations, basal haemoglobin, corticoids use and PS score: 2.3;95% CI: 1.3-3.9, p=0,002). LIPI 2 group patients had also worse DCR (45% vs 64% in LIPI0 and 74% in LIPI1, p=0.012). ConclusionsLIPI score was able to define a group of patients with poor benefit from pembrolizumab monotherapy in such a selected population (advanced NSCLC with high PD-L1 expression) with high probability to get benefit from it according to KN-024. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.