Superior efficacy of immunotherapy‐based combinations over monotherapy for EGFR‐mutant non‐small cell lung cancer acquired resistance to EGFR‐TKIs

BACKGROUND: While prospective clinical studies on immunotherapy in epidermal growth factor receptor (EGFR) mutant non‐small‐cell lung cancer (NSCLC) with acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) are ongoing, this study aimed to investigate the outcomes of immunotherapy combinations in such a population in a real‐world setting. METHODS: The clinical data of pretreated EGFR‐mutated NSCLC patients who acquired EGFR‐TKI resistance and received immunotherapy were retrospectively analyzed in this study. Progression‐free survival (PFS) was assessed using the Kaplan‐Meier log‐rank test, and univariate and multivariate analysis were performed. RESULTS: A total of 31 patients were analyzed in this study. A total of 25 (80.6%) patients received combination immunotherapy. In the univariate analysis, patients who received combination immunotherapy seemingly acquired longer PFS than those who received monotherapy, although there was no significant difference (3.42 months vs. 1.61; P = 0.078; hazard ratio (HR) 0.43, 95% CI: 0.16–1.13). Patients who received antiangiogenic drugs prior to immunotherapy acquired better PFS (3.42 months vs. 1.58; P = 0.027; HR 0.37, 95% CI: 0.15–0.93), while patients with liver metastasis had inferior PFS (2.04 months vs. 3.42; P = 0.031; HR 2.83, 95% CI: 1.05–7.60). Furthermore, multivariate analysis confirmed that the above three factors had independent prognostic value. CONCLUSIONS: The study revealed that immunotherapy combinations are better choices than single‐agent regimens in previously treated and EGFR‐mutant NSCLC patients with progressive disease. In addition, antiangiogenic drugs administered before immunotherapy might be a favorable prognostic factor, while liver metastasis was associated with a short PFS in this setting. In future, more robust and prospective clinical trial results are expected to guide clinical practice. KEY POINTS: SIGNIFICANT STUDY FINDINGS: Immunotherapy‐based combination therapies are better choices than single‐agent regimens in heavily treated EGFR‐mutant NSCLC patients. WHAT THIS STUDY ADDS: Patients without liver metastasis and with prior antiangiogenic drugs obtained more benefit from immunotherapy in this setting.