FH-006 Versus Investigator's Choice of Chemotherapy in Patients With Locally Advanced, Recurrent, or Metastatic Esophageal Squamous Cell Carcinoma Who Have Failed Prior PD-1/PD-L1 Inhibitor Combined With Platinum-Based Chemotherapy.

Inclusion Criteria:

1. Age 18 to 75 years old (including boundary values)
2. Volunteer to participate in this clinical study and sign informed consent;
3. ECOG score 0-1;
4. Expected survival ≥3 months;
5. Patients diagnosed with esophageal squamous cell carcinoma by histological or cytological examination;
6. Previously, only PD-1/PD-L1 Inhibitor Combined With Platinum-Based Chemotherapy were received;
7. There is at least one measurable lesion that meets the RECIST 1.1 criteria;
8. Adequate bone marrow and organ function.

Exclusion Criteria:

1. Received anti-tumor therapies such as chemotherapy, radiotherapy, biological therapy, targeted therapy, or immunotherapy within 4 weeks before the first dose of the study
2. Toxicities caused by previous anticancer therapy were not recovered to CTCAE 6.0 Grade≤1;
3. Individuals with Leptomeningeal metastasis or Active brain metastases;
4. Individuals with a history of GI perforation or fistula, unstable GI bleeding;
5. Individuals with a history of severe cardiovascular and cerebrovascular diseases;
6. The researcher determined that there are other situations that are not suitable for participation.