Advanced Esophageal Cancer

The purpose of this study is to find out whether adding the drug 2141-V11 to standard treatment (anti-PD-1 immunotherapy with or without 5-FU) is a safe treatment approach for participants with advanced esophageal, gastric, or gastroesophageal junction adenocarcinoma

The goal of this clinical trial is to learn if ADC drug MC002 works to treat locally advanced/metastatic solid tumors in adults. It will also learn about the safety of MC002. The main questions it aims to answer are: Does participants tolerate the drug MC002 ? What medical problems do participants have when treating with MC002? Does participants benefit from the MC002 . Participants will: Intravenous infusion MC002 every 3 weeks in clinical Visit the clinic once every 3 weeks for checkups and tests Keep a diary of their symptoms