Immunotherapy plus chemotherapy versus chemotherapy alone in metastatic non–small-cell lung cancer: A systematic review with meta-analysis.

Abstract

e20700 Background: Palliative systemic therapy is the primary approach for stage IV non-small cell lung cancer(NSCLC). For patients with NSCLC that lacks targetable mutations, immunotherapy alone or in combination with chemotherapy has become a promising alternative, focusing survival and quality of life. Our objectives were to review, summarize and compare the evidence of immunotherapy plus chemotherapy in first-line treatment in comparison with chemotherapy alone in patients with metastatic NSCLC in terms of effectiveness. Methods: A systematic review of randomized controlled trials (RCTs) was planned. PubMed, Embase and Lilacs were searched for trials evaluating metastatic NSCLC patients, comparing chemotherapy alone versus chemotherapy plus anti-PD1, anti-PDL1 or anti-CTLA-4 agents. Four investigators independently extracted characteristics and results of identified studies and performed standardized quality ratings. Meta-analyses for overall survival (OS), progression-free-survival (PFS), overall response rates (ORR) and toxicities were performed. Results: Six RCTs met the inclusion criteria. One trial with anti-PD-L1 (Atezolizumab), three trials with anti-PD-1 (Pembrolizumab) and two trials with anti-CTLA-4 (Ipilimumab) were included. Three trials included non-squamous carcinomas, two trials included squamous cell carcinoma and one trial included all NSCLC. The combination of anti-PD-1 or anti-PDL1 to chemotherapy improved OS (Hazard Ratio [HR] for death, 0.62; 95% confidence interval [CI], 0.49 to 0.79; p < 0.0001). This combination also improved PFS (HR for progression or death, 0.57; 95% CI, 0.51 to 0.63; p < 0.00001) and ORR (Odds Ratio [OR], 2.55; 95% CI, 1.80 to 3.61; p < 0.00001). The combination of anti-CTLA-4 to chemotherapy slightly increased the PFS (HR 0.84; 95% CI, 0.73 to 0.96; p = 0.01), but not OS (HR 0.92; 95% CI, 0.80 to 1.05; p = 0.21) or ORR (OR 0.92; 95% CI, 0.71 to 1.19; p = 0.52). General and immune mediated adverse events were higher in all combination groups. Conclusions: In patients with previously untreated metastatic squamous and non-squamous NSCLC without EGFR or ALK mutations, the addition of anti-PD-1 or anti-PD-L1 to standard chemotherapy resulted in significantly longer overall survival and progression-free survival than chemotherapy alone.