The efficacy and safety of PD-1/PD-L1 inhibitors versus chemotherapy in patients with previously treated advanced non-small-cell lung cancer: A meta-analysis

BACKGROUND: Immune checkpoint inhibitor therapy for non-small cell lung cancer is widely used in clinical practice. However, there has not been a systematic statistical proof of the efficacy of PD-1 inhibitors in patients with advanced cancer. This meta-analysis aims to evaluate its efficacy and related influencing factors, so as to provide a basis for clinical diagnosis and treatment. OBJECTIVE: To assess the effectiveness and safety of programmed death-1 (PD-1)/PD ligand 1 (PD-L1) inhibitors versus chemotherapy as second-line or late-line treatment for patients with advanced non-small-cell lung cancer (NSCLC) via a systematic review of published randomized controlled trials (RCTs). METHODS: Studies were identified through PubMed, EMBASE, and Cochrane Library electronic databases. RevMan 5.3.5 was used to analyze the data extracted from all eligible studies. RESULTS: All 4122 eligible patients from 8 RCTs were included in this study. The meta-analysis showed that PD-1/PD-L1 inhibitors could significantly improve overall survival (hazards ratio [HR] 0.71, 95% confidence interval [CI] 0.66–0.77, P < .001), progression-free survival (HR 0.88, 95%CI 0.81–0.94, P = .01), and objective response rate (HR 2.03, 95%CI 1.66–2.49, P < .001) compared with chemotherapy drugs. The incidence of side effects of any grade (HR 0.34, 95%CI 0.29–0.39, P < .001) or grades 3 to 5 (HR 0.15, 95%CI 0.10–0.23, P < .001) consistently showed that PD-1/PD-L1 inhibitors were safer than chemotherapy. Furthermore, subgroup analysis based on tumor proportion score or pathology classification revealed that PD-1/PD-L1 inhibitors significantly improved overall survival compared with chemotherapy. CONCLUSION: As a second-line or late-line treatment, PD-1/PD-L1 inhibitors are safer and more effective than chemotherapy in patients with advanced NSCLC.