Abstract
INTRODUCTION: The real-world effectiveness of combination treatment with cytotoxic chemotherapy and programmed cell death protein-1 or programmed death-ligand 1 inhibitor for NSCLC, especially for the elderly (aged ≥75 y) or those with poor performance status (≥2), has not been fully elucidated. We investigated the real-world effectiveness and safety of this combination therapy in these populations. METHODS: This multicenter retrospective study evaluated patients who are chemo-naïve with advanced NSCLC who received a combination of platinum, pemetrexed, and pembrolizumab between December 2018 and June 2019. This was an updated prespecified secondary analysis with the primary objective of investigating the safety and effectiveness in this cohort. RESULTS: Overall, 299 patients were included. Multivariate analysis identified performance status (0-1) and programmed death-ligand 1 tumor proportion score (≥50%) as significant independent predictors of progression-free survival (p = 0.007, and p = 0.003, respectively). The incidence of severe adverse events (AEs) was higher in the elderly and those with poor performance status than in their younger and good performance status counterparts. A total of 71 patients developed AEs that led to treatment discontinuation, and AE-related treatment discontinuation occurred at a significantly higher rate in older patients (median [range]) (70 [46-82] y) than in younger patients (68 [31-84] y) (p <0.001). CONCLUSIONS: Combination treatment with pembrolizumab plus chemotherapy had low real-world effectiveness for poor performance status patients. Severe AEs occurred at a higher rate in the elderly and poor performance status patients, and the AE-related treatment discontinuation rate increased with age. Physicians should be cautious about using this regimen, especially in the elderly and poor performance status patients.