Comparison of treatment outcome between first-line combination immunotherapy (anti-PD-L1 or anti-PD1) with or without chemotherapy and chemotherapy alone in advanced non-small cell lung cancer patients in tertiary care hospital

Background: Despite promising outcomes of first-line immunotherapy with or without chemotherapy in advanced non-small cell lung cancer (NSCLC), limited accessibility due to reimbursement was remain the problem in low to middle income countries. This study aimed to evaluate real-world effectiveness of immunotherapy in patients with advanced NSCLC in Northern Thailand. Method: A retrospective, single-centered cohort, was conducted. Patients with advanced NSCLC who underwent PD-L1 testing (excluding EGFR and ALK mutations) and were treated with immunotherapy or without chemotherapy or chemotherapy alone were included. The primary end point was progression-free survival (PFS). The secondary endpoints were overall survival (OS), objective response rate (ORR), and adverse events. Results: A total of 123 patients, of which 21 patients received immunotherapy-based regimen and 102 patients received chemotherapy alone. The median PFS was 11.9 months in immunotherapy-based group compared to 5.93 months in the chemotherapy group, with a. hazard ratio (HR) of 0.4 (95% confidence interval [CI], 0.23 to 0.68; p = 0.001). Similarly, the median OS was 26.68 months in the immunotherapy-based group and 11.21 months in the chemotherapy group, with HR of 0.42 (95% CI 0.22-0.8; p = 0.009). ORRs were significantly higher in the immunotherapy-based group, with 65% of patients showing a response compared to 32% in the chemotherapy group (p = 0.006). Conclusion: The result of this real-world study in patients with advanced stage NSCLC indicate that first-line immunotherapy-based regimen was associated with significantly greater PFS, OS, and ORR with a safety profile consistent with pivotal studies.