Abstract 6487: Exploratory study of camrelizumab combined with chemotherapy as second-line treatment for advanced esophageal squamous cell carcinoma

Abstract Background: Patients with advanced esophageal squamous cell carcinoma (ESCC) face a poor prognosis and limited options after first-line therapy failure. This study aims to evaluate the efficacy and safety of camrelizumab combined with chemotherapy as a second-line treatment in patients who with or without prior immunotherapy exposure. Method: This single-center, multi-cohorts, phase II exploratory clinical trial enrolled patients with locally recurrent or metastatic ESCC who had either failed or were intolerant to first-line treatment. Patients were stratified into two cohorts: those who had previously received immunotherapy (Cohort 1) and those who had not (Cohort 2). All patients received camrelizumab (Q3W, up to 2 years) combined with nab-paclitaxel or fluorouracil based chemotherapy (Q3W, 4-6 cycles).The primary endpoint was progression-free survival (PFS). Results: Between May 2021 and September 2025, 40 patients were enrolled, with 20 patients in each cohort. The median age was 67 years in Cohort 1 and 66 years in Cohort 2.The median age was 67 years in Cohort 1 and 66 years in Cohort 2. The cohorts comprised 18 (90%) and 15(75%) males;15(75%) and 15(75%) with an ECOG performance status of 1; 10% and 15% with pulmonary metastases; and 55% and 45% with lymph node metastases, respectively. According to RECIST 1.1, among the 15 and 18 evaluable patients in Cohorts 1 and 2, the objective response rate (ORR) was 33.3% and 50.0%, and the disease control rate (DCR) was 93.3% and 88.9%, respectively. The median progression-free survival (mPFS) was 4.5 months(95%CI 2.13-6.8 ) in Cohort 1 and 9.5 months(95%CI 2.7-16.4 ) in Cohort 2. The median overall survival(mOS) was not reached.The most common adverse events (AEs) were lymphocyte count decreased (90% and 75%), anemia (85% and 70%), and decreased neutrophils (50% and 40%), which were grade 1-3. No grade 4 or 5 AEs occurred.The most common immune-related AEs (irAEs) was reactive cutaneous capillary endothelial proliferation(64.% and 57.1%), which was grade 1-2 in all cases. Conclusion: Camrelizumab combined with chemotherapy showed good antitumor efficacy and safety in advanced ESCC as second-line treatment, regardless of whether the patients have previously received immunotherapy. Citation Format: Linlin Wang, Bingjie Fan, Bing Zou, Aiqin Gao, Shijiang Wang, Chunni Wang, Qian Shao, Yishan Yu, Hong Zhao, Jinzhi Wang, Yan Yi, Qingxi Yu. Exploratory study of camrelizumab combined with chemotherapy as second-line treatment for advanced esophageal squamous cell carcinoma abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6487.