Neoadjuvant programmed death-1 blockade plus chemotherapy in locally advanced esophageal squamous cell carcinoma.

Abstract

e16076 Background: Immunotherapy is effective in treating advanced esophageal squamous cell carcinoma (ESCC), but little is known about its role in the setting of neoadjuvant therapy. Methods: Data from a retrospective cohort and a prospective cohort of locally advanced ESCC patients were analyzed. All patients included had received neoadjuvant camrelizumab plus nab-paclitaxel and S1 capsule followed by radical esophagectomy. The main purpose of this study was to evaluate the safety and feasibility of the neoadjuvant treatment. In addition, pathological response and the relationship between tumor immune microenvironment features (TIME)/tumor mutational burden (TMB) and treatment response were also explored. Results: A total of 25 locally advanced ESCC patients from both cohorts were included, of which 12 from the retrospective cohort and 13 from the prospective cohort. Only two patients experienced grade 3 or 4 adverse events, including onehad anemia and the other (4%) had limb numbness. No surgical delay or perioperative death was reported. Sixteen patients (64%) responded to the treatment, eight (32%) with a complete pathological response and eight (32%) with a major pathological response. Neither programmed death-ligand 1 expression nor TMB was correlated with treatment response. In terms of TIME analysis, patients with better pathological response in the primary tumor had significantly higher abundance of CD56dim natural killer cells (109 vs 32, P= 0.01), while lower density of M2-tumor-associated macrophages was associated with numerically better pathological response in the lymph nodes (47 vs 163.1, P= 0.55). Conclusions: Neoadjuvant camrelizumab plus nab-paclitaxel and S1 is safe, feasible and effective, and the efficacy could be predicted by TIME, which is worthy of further investigation. Clinical trial information: ChiCTR2000029807.