This is an interventional study to assess the safety, tolerability, efficacy, pharmacokinetics, and immunogenicity of CM518D1 in patients with advanced solid tumors.

Inclusion Criteria:

• 1. Male or female ≥ 18 and ≤75 years of age.
• 2. Subjects with histologically or cytologically confirmed advanced solid tumors.
• 3. At least one measurable lesion according to RECIST v1.1.
• 4. Expected survival time ≥ 3 months as judged by the Investigator.

Exclusion Criteria:

• 1. Subjects who have received any chemotherapy or any drug therapy for antitumor treatment including monoclonal antibodies, targeted therapy, radioimmunoconjugates, or Antibody-Drug Conjugates(ADCs), or any investigational product therapy for anti-tumor therapy within 28 days prior to the first dose or within 5 half-lives (whichever is shorter).
• 2. Subjects who have received major surgery within 28 days prior to the first dose.
• 3. Subjects who have received radiotherapy within 21 days prior to the first dose.
• 4. Subjects who have received systemic glucocorticoid therapy (more than 10 mg of prednisone or equivalent daily) or other forms of immunosuppressive therapy within 7 days prior to the first dose.
• 5. Subjects who have received any CDH17-targeted therapy.
• 6. History of other malignancies within 5 years prior to the first dose, excluding cured basal or squamous cell carcinoma of skin, carcinoma cervix in situ, or breast ductal carcinoma in situ.
• 7. Hypersensitivity to the investigational drug or its excipients.
• 8. Pregnant or lactating female patients.