Abstract
BACKGROUND: This trial evaluated the efficacy and safety of anti-programmed cell death 1 antibody (SCT-I10A) and anti-epidermal growth factor receptor (EGFR) antibody (SCT200) in patients with previously treated advanced esophageal squamous cell carcinoma (ESCC) (trial registration number: NCT04229537). METHODS: This multicenter, open-label, phase 1b clinical trial enrolled patients with advanced ESCC refractory or intolerant to standard chemotherapy. Patients who had not received prior treatment with programmed death-(ligand)1 (PD-(L)1) immune checkpoint inhibitors (ICIs) or anti-EGFR antibodies comprised cohort 1A, and those who had previously failed treatment with PD-(L)1 ICIs or anti-EGFR antibodies comprised cohort 1B. Eligible patients were treated with SCT200 and SCT-I10A. RESULTS: Seventy patients were enrolled. The objective response rate was 25.7%, with a median overall survival and progression-free survival of 6.90 months and 3.98 months, respectively. Twenty-nine patients previously underwent ICI treatment with an objective response rate of 17.24%, median overall survival of 6.08 months, and median progression-free survival of 3.98 months. Grade 3 or higher adverse events were observed in 43.3% and 52.5% of patients in cohort 1A and 1B, respectively. CONCLUSIONS: SCT-I10A plus SCT200 demonstrated durable antitumor activity with a manageable safety profile in previously treated patients with advanced ESCC, even in patients who had previously failed anti-PD-(L)1 therapy.