P1.04-34 Efficacy and Safety of First-Line Pembrolizumab Monotherapy in Elderly Patients (Aged ≥ 75 years) with Non-Small Cell Lung Cancer

Abstract

Pembrolizumab is effective as first-line treatment for advanced non-small cell lung cancer (NSCLC) patients expressing high programmed death-ligand 1 (PD-L1). However, it is unclear whether the efficacy of first-line pembrolizumab treatment in elderly patients (aged ≥75 years) is similar to that in non-elderly patients expressing high PD-L1. Therefore, we aimed to investigate the efficacy and safety of first-line pembrolizumab monotherapy in elderly patients with NSCLC expressing high PD-L1. Between February 2017 and February 2018, 128 patients (comprising 47 elderly) with advanced NSCLC expressing high PD-L1 received first-line pembrolizumab monotherapy at 10 Japanese institutions. Baseline characteristics, efficacy of pembrolizumab treatment, and adverse events were recorded. Overall, 47 patients (40 men and 7 women) (median age, 79 [range, 75–88] years) were included in our analysis. In these patients who received first-line pembrolizumab monotherapy, the overall response, disease control rates, median progression-free survival (PFS), and overall survival (OS) were 53.1%, 74.4%, 7.0 months, and not reached, respectively. Common adverse events included anorexia, fatigue, skin rash, and hypothyroidism. Two treatment-related deaths due to pneumonitis and infection were noted. First-line pembrolizumab monotherapy with non-progressive disease (PD) was associated with better PFS. Pembrolizumab monotherapy with good performance status and non-PD was also linked to better OS. First-line pembrolizumab monotherapy among elderly patients with NSCLC expressing high PD-L1 was effective and safe and showed outcomes equivalent to those in non-elderly patients. First-line pembrolizumab monotherapy without PD, and with good performance status and non-PD, might be associated with better PFS and OS, respectively.