P3.12-11 Association of the Lung Immune Prognostic Index (LIPI) with Outcomes for Immune Checkpoint Inhibitors in Diffuse SCLC Patients

Abstract

Pretreatment LIPI (Lung Immune Prognostic Index), based on derived NLR (neutrophils/[leucocytes-neutrophils] ratio) and lactate dehydrogenase (LDH) has been associated with outcomes for immune checkpoint inhibitors (ICI) in advanced NSCLC patients. We tested whether LIPI has the same role in diffuse small cell lung cancer (SCLC) patients. Baseline dNLR and LDH and clinical data were retrospectively collected in SCLC patients, treated with ICI (PD1 inhibitor, PDL1 inhibitors +/- CTLA4 inhibitor) from April 2014 to Jan. 2018 (N=66) from 6 European centers. LIPI was calculated combining dNLR and LDH, stratifying 3 risk groups: good (dNLR<3+LDH<upper limit of normal (ULN), intermediate (dNLR>3 or LDH>ULN), poor (dNLR>3+LDH>ULN). The primary endpoint was overall survival (OS), and secondary endpoint was progression-free survival (PFS). Fifty-three patients (80%) were males, 58 (88%) smokers and all patients had PS ≤1, with median age 63 years (41-82). PDL1 was ≥ 1% by immunohistochemistry in 6 patients, and unknown in 60 patients. The median of prior lines was 1 (0-6). Platinum-based therapy was the prior line in 63 (95%) patients, with ORR of 88%. The median PFS and OS with ICI were 2.7 months (m) [95% CI 1.87-4.43] and 10.3 m [95% CI 5.8-12.6]. dNLR was greater than 3 in 16 (25%) and LDH> Upper Limit of Normal (ULN) in 33 (50%) patients. Based on both, LIPI stratified the population in 3 groups: 26 patients as good (40%), 29 (45%) as intermediate and 10 (15%) as poor LIPI risk groups. LIPI was an independent factor for OS (HR 2.77, 95% CI 1.07-7.14, P=0.03) and PFS (HR 3.13, 1.37-7.16, P=0.01). Median OS for good, intermediate, and poor risk groups were 11.4 m [95% CI 5.5-27.3], 11 m [95% CI 6.8-not-reached (NR)] and 2.3 m [95% CI 0.7-NR], respectively (P=0.004). Median PFS for good, intermediate, and poor risk groups were 3 m [95% CI 1.9-12.6], 2.8 m [95% CI 1.6-6.0 and 1.2 m [95% CI 0.47-NR], respectively (P=0.004). Baseline LIPI poor risk group is associated with poor outcomes for ICI in diffuse SCLC patients. LIPI effect in a validation cohort is currently evaluated.