• Patients voluntarily joined the study, signed the informed consent, and had good compliance;

• Patients ≥18 years of age (at the time of signing the informed consent); Eastern Cooperative Oncology Group Performance Status (ECOG-PS) score: 0-2; Expected survival of more than 3 months;

• Patients were pathologically confirmed as inoperable locally advanced or metastatic medullary thyroid carcinoma (MTC), possessing imaging or clinical evidence of disease progression within the first 14 months of enrollment;

• Having at least one measurable lesion (assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1);

• Major organ functions meet the following criteria within 7 days prior to the treatment:

‣ Blood routine examination shall meet the following standards (no transfusion within 14 days) :

• Hemoglobin (Hb) ≥85g/L;

∙ Absolute Neutrophil Count (ANC) ≥1.5×109/L;

∙ Platelet (PLT) ≥80×109/L；

⁃ Biochemical examination shall meet the following standards:

• Total bilirubin (TBIL) ≤1.5 times the upper limit of normal (ULN);

∙ Alanine transferase (ALT) and Aspartate transferase (AST) ≤2.5×ULN; If accompanied by liver metastasis, ALT and AST ≤5×ULN；

∙ Serum creatinine (Cr) ≤1.5×ULN or Creatinine clearance rate (CCr) ≥60ml/min；

• Female patients of reproductive age should agree that birth control (such as intrauterine device, birth control pills, or condoms) must be used during the study period until six months after completion; Having a negative serum pregnancy test within 7 days prior to study enrollment, and must be non-lactating; Male patients should agree to use contraception during the study period until six months after the end of the study.