This is a large clinical study carried out at multiple hospitals. Participants will be randomly assigned to one of two groups: one group will receive a new medicine called YL201, and the other group will receive standard chemotherapy chosen by the doctor.
The purpose of the study is to see whether YL201 works better and is safer for people with locally advanced or metastatic esophageal squamous cell carcinoma whose first-line treatment has stopped working.
The study will also look at how YL201 is processed in the body (Pharmacokinetics), whether it triggers any immune reactions, and whether certain biological markers can help predict how well it works.
Age: ≥18 years;
Voluntary participation in this study with signed informed consent and good compliance.
ECOG PS score: 0-1;
estimated life expectancy >3 months;
Other malignancies within 5 years prior to first dose or currently concurrent malignancies.
Prior treatment-related adverse events not resolved to ≤Grade 1 per CTCAE v5.0, except for alopecia (any grade), hyperpigmentation (any grade), peripheral neuropathy (≤ Grade 2), and lymphopenia (≤ Grade 3).
Major surgery, significant traumatic injury within 4 weeks prior to first dose, or anticipated need for major surgery during study treatment
Any arterial thromboembolic event within 6 months prior to randomization, or venous thromboembolic events of Grade ≥ 3 according to NCI CTCAE version 5.0.