Clinical predictive markers of response to immune checkpoint inhibitor therapy in advanced non-small cell lung cancer.

Abstract

e21044 Background: Overweight and obesity have been associated with improved overall survival (OS) and progression-free survival (PFS) in patients treated with immune checkpoint inhibitors (ICI). EPSILoN score (EPSILoN), comprised of five clinical variables (smoking, Eastern Cooperative Oncology Group performance status, liver metastases, lactate dehydrogenase (LDH), and neutrophil-lymphocyte ratio), is a known predictive marker of response to ICI. This study aims to validate body mass index (BMI) and EPSILoN as predictive markers of response in frontline treatment of advanced non-small cell lung cancer (NSCLC) with ICI with or without concomitant chemotherapy. Methods: Patients with advanced NSCLC who received frontline ICI were identified using the electronic medical record. PFS and OS were retrospectively evaluated and stratified based on baseline BMI and EPSILoN. Due to lack of routine LDH testing, a modified EPSILoN (mEPSILoN) was used. For statistical analysis, log-rank tests were used to compare PFS and OS between groups, and Kaplan-Meier survival curves were used to report PFS and OS. Results: Thirty-six normal weight (NW) and 25 overweight and obese (OWO) patients were studied. Median PFS (mPFS) for OWO vs NW patients was 8.90 months vs 5.53 months (HR 0.54; 95% CI, 0.30-0.96; p = 0.04). mPFS at 12 months was 45% for OWO patients vs 23% for NW patients. Of the patients with PD-L1 ≥ 50%, 14 patients were NW and 11 patients were OWO. Among patients with PD-L1 ≥ 50%, mPFS for OWO was not reached (NR) vs 6.73 months in NW patients (HR 0.23; 95% CI, 0.09-0.60; p = 0.003), and the percent of patients that were PF at 12 months was 71% vs 15%. Of 56 patients with a calculable mEPSILoN, 29 patients had baseline mEPSILoN 1 and 27 patients had mEPSILoN 2-3. Median OS for patients with mEPSILoN 1 vs 2-3 was NR vs 11.13 months (HR 0.32; 95% CI, 0.14-0.76; p = 0.01) and 78% vs 49% survived at 12 months. Conclusions: OWO and lower mEPSILoN were associated with longer PFS and OS, respectively, in patients with advanced NSCLC who were treated with frontline ICI with or without concomitant chemotherapy, regardless of PD-L1 expression. These findings are consistent with recent studies that have reported these parameters as predictive markers of response in patients with NSCLC. However, this is the first study to our knowledge to evaluate these markers in frontline ICI treatment with or without chemotherapy.[Table: see text]