Final analysis of camrelizumab plus chemotherapy for untreated advanced or metastatic esophageal squamous cell carcinoma: The ESCORT-1st trial.

Background: The interim analysis of the randomized phase 3 ESCORT-1st study demonstrated significantly longer overall survival (OS) and progression-free survival (PFS) for camrelizumab-chemotherapy than placebo-chemotherapy in untreated advanced/metastatic esophageal squamous cell carcinoma (ESCC). Here, we present the final analysis of this study and investigate potential indicators associated with OS.

Methods: Patients were randomized 1:1 to receive camrelizumab (200 mg) or placebo, both in combination with up to six cycles of paclitaxel (175 mg/m²) and cisplatin (75 mg/m²). All treatments were administered intravenously every 3 weeks. The co-primary endpoints were OS and PFS assessed by the independent review committee.

Findings: As of April 30, 2022, the median OS was significantly longer in the camrelizumab-chemotherapy group compared to the placebo-chemotherapy group (15.6 [95% confidence interval (CI): 14.0-18.4] vs. 12.6 months [95% CI 11.2-13.8]; hazard ratio [HR]: 0.70 [95% CI 0.58-0.84]; one-sided p < 0.0001), with 3-year OS rates of 25.6% and 12.8% in the two groups, respectively. The 2-year PFS rates were 20.4% in the camrelizumab-chemotherapy group and 3.4% in the placebo-chemotherapy group. Adverse events were consistent with those reported in the interim analysis. Higher PD-L1 expression correlated with extended OS, and multivariate analysis identified sex and prior history of radiotherapy as independent indicators of OS.

Conclusions: The sustained and significant improvement in efficacy with camrelizumab-chemotherapy compared to placebo-chemotherapy, along with the absence of accumulating or delayed toxicities, supports the long-term use of camrelizumab-chemotherapy as a standard therapy in untreated advanced/metastatic ESCC.

Funding: This study was funded by Jiangsu Hengrui Pharmaceuticals Co., Ltd.