Sintilimab in patients with advanced esophageal squamous cell carcinoma refractory to previous chemotherapy: A randomized, open-label phase II trial (ORIENT-2).
Jianming Xu, Yi Li, Qingxia Fan, Yongqian Shu, Zhijun Wu, Tongjian Cui, Kangsheng Gu, Min Tao, Xiuwen Wang, Chengxu Cui, Nong Xu, Juxiang Xiao, Quanli Gao, Yunpeng Liu, Tao Zhang, Hui Zhou, Yan Wang, Linxinyu Xu, Zhuo Ma, Yanqi Wang
Abstract
4511 Background: Patients (pts) with advanced esophageal squamous cell carcinoma (ESCC) refractory to first-line chemotherapy have limited treatment options. The study aims to evaluate the efficacy and safety of sintilimab, a PD-1 inhibitor, versus chemotherapy in these pts, and explore predictive value of PD-L1 and neutrophil-to-lymphocyte ratio (NLR) on efficacy of sintilimab. Methods: The open-label, multi-center phase 2 trial (NCT03116152) enrolled advanced ESCC pts refractory to first-line chemotherapy, and randomly assigned (1:1) them to receive sintilimab (200mg, Q3W) or chemotherapy (paclitaxel, 175mg/m 2 , Q3W; or irinotecan, 180mg/m 2 , Q2W), intravenously. The primary endpoint was overall survival (OS). Explorative endpoint were effects of PD-L1 and NLR on efficacy of sintilimab. Results: From May 16, 2017 to Aug 30, 2018, 190 pts were randomly assigned to sintilimab or chemotherapy (n = 95 per group). With the median follow-up of 7.2 months for sintilimab group and 6.2 months for chemotherapy group, the median OS in sintilimab was significantly higher than chemotherapy (7.2m vs. 6.2m, hazard ratio [HR] 0.70, P = 0.034). The objective response rate (ORR) was greater in sintilimab than chemotherapy with 12.6% vs. 6.3%, and the median duration of response was longer (8.3m vs. 6.2m). Incidences of treatment-related adverse events (TRAEs) of any grade (54.3% vs. 90.8%) and of grade 3-5 (20.2% vs. 39.1%) were both numerically less in sintilimab than in chemotherapy. The ORR in sintilimab versus chemotherapy in pts with tumor PD-L1 tumor proportion score (TPS) ≥1% and with TPS ≥10% were 20.2% vs. 0%, and 35.7% vs. 0%, respectively. In sintilimab group, pts with low NLR ( < 3) had a significant longer median OS (HR 0.54, P = 0.019) than with high NLR. Conclusions: Sintilimab was superior to chemotherapy with a significantly prolonged survival benefit and a favorable safety profile in pts with advanced ESCC refractory to first-line chemotherapy. High tumor PD-L1 expression (TPS ≥1% or ≥10%) might indicate more response benefit to sintilimab for these pts, and low NLR might be a positive predictive factor for sintilimab. Clinical trial information: NCT03116152 .