155 A META-ANALYSIS OF EFFICACY AND SAFETY OF ANTI-BODIES TARGETING PD-1 IN TREATMENT OF ADVANCED ESOPHAGEAL CANCER

Systemic chemotherapy is the first choice for patients with advanced esophageal cancer. However, due to drug resistance and dose-limiting toxicity, a large number of patients in China have not been treated. A novel therapy based on programed death 1 (PD-1) inhibitors has been proved to be effective in advanced esophageal cancer.This article is a meta-analysis aiming to systematically evaluate the efficacy and safety of anti-PD-1 therapy in patients with esophageal cancer. Methods Data were collected from eligible studies searched from PubMed, Web of Science, Cochrane Library and Embase. Pooled hazard ratio (HR) for overall survival (OS) and progression-free survival (PFS) was estimated to assess the efficacy of PD-1 inhibitors versus chemotherapy, and pooled odds ratio (OR) was calculated for objective response rate (ORR). The analysis among patients tested with different PD-1 status was also performed to figure out the relationship between PD-1 status and efficacy of anti-PD-1 therapy. The OR for occurrence of treatment-related adverse effect was calculated to assess the safety of anti-PD-1 therapy. Results A total of 8 studies were analyzed. Compared with patients with chemotherapy, patients with anti-PD-1 therapy had a significant improvement in OS (HR = 0.80, 95% CI: 0.70–0.91, P = 0.001), but no significant relationship was observed in ORR (HR = 1.87, 95% CI: 0.82–4.25, P = 0.13) and PFS (HR = 0.94, 95% CI: 0.70–1.26, P = 0.67). A similar result was observed in esophageal squamous cell carcinoma (ESCC). The PD-L1 status has no obvious connection with the efficacy of anti-PD-1 therapy. The incidence of grade 3 to 5 treatment-related adverse effect(AE) in anti-PD-1therapy was distinctly lower than that in chemotherapy, but there is no statistical difference in all treatment-related AE. Conclusion Anti-PD-1 therapy significantly prolonged the OS when compared with chemotherapy, while no significantly difference in PFS and ORR for the population of esophageal cancer, ESCC， PD-L1 positive. Based on the analysis of grade 3 to 5 treatment-related adverse effect events, a lower risk was associated with the anti-PD-1 therapy versus chemotherapy.