Becotatug Vedotin in Combination With Immunotherapy and Multimodality Radiotherapy for Esophageal Squamous Cell Carcinoma in the Second-line or Later Setting

Becotatug vedotin (MRG003): 2.0 mg/kg, D1,Q3W, starting at least 30 minutes after completion of the ICI infusion. Immune checkpoint inhibitor: Investigator's choice, including but not limited to camrelizumab, tislelizumab, and pembrolizumab; Q3W, IV, Day 1, with infusion duration per the respective prescribing information. Multimodal radiotherapy: Initiated within the first 2 cycles of systemic therapy (no later than the end of Cycle 2), targeting the primary lesion and/or metastatic lesions. An individualized radiotherapy plan is delivered, using conventionally fractionated radiotherapy or SBRT, at approximately 50-60 Gy in 25-30 fractions (or a biologically equivalent dose/fractionation schedule). Investigators may appropriately adjust the timing, dose, and fractionation. Whether the ICI is withheld during radiotherapy is left to the investigator's discretion based on the patient's clinical condition.