482. SECOND-LINE OF CAMRELIZUMAB PLUS NIMOTUZUMAB IN ADVANCED ESOPHAGEAL SQUAMOUS CELL CARCINOMA (ESCC): A SINGLE-ARM, OPEN-LABEL, PHASE 2 TRIAL

Background Anti-PD-1 antibody camrelizumab monotherapy is recommended for the treatment of advanced second-line ESCC. However, the long-term survival is limited, and new effective treatments are needed. Epidermal growth factor receptor (EGFR) is usually over-expressed in more than 50% of ESCC patients(pts), and is a potential target for the treatment of ESCC. Our study aimed to assess the efficacy and safety of combination with camrelizumab and nimotuzumab (EGFR inhibitor) as second-line treatment for advanced ESCC. Methods This ongoing phase II trial in four sites in China enrolled pts aged 18–75 with unresectable locally advanced, locally recurrent, or metastatic ESCC that progressed or were intolerant after first-line treatment, and ECOG PS score of 0–1. Pts received 200 mg intravenous camrelizumab (Q2W) plus 400 mg intravenous nimotuzumab (QW) in 4-week cycles until disease progression, unacceptable adverse events (AEs) or withdrawal of consent. The primary endpoint was investigator-assessed objective response rate (ORR), overall survival (OS). Secondary endpoints included disease control rate (DCR), progression-free survival (PFS). Results From 2/2021 to 4/2023, 28 of the planned 42 pts with an average 63 years old had been enrolled, including 18 (64%) males and 21 (75%) patients with an ECOG PS score of 1. Nine pts had previously used anti-PD-1/PD-L1 antibody. Among the 21 evaluable pts, 8 pts achieved partial response (PR), 13 pts stable disease (SD), illustrating an ORR of 38.0% and a DCR of 100%. Median PFS was not reached. 82.1% pts experienced adverse event(AE), with 21.4% being grade ≥ 3. The most frequent AE were RCCEP (57.1%), neutrophil count decreased (17.8%), white blood cell decreased (14.2%). Conclusions Camrelizumab plus nimotuzumab demonstrated encouraging clinical efficacy and acceptable safety as second-line treatment, and might be a favorable option for pts with advanced ESCC. The study enrollment is ongoing, and further survival and safety data will be reported in the future. Clinical trial information: NCT03766178.