This is a multi-center, open-label, Phase 1 clinical study of ZGGS15 for the treatment of patients with advanced solid tumors.

Inclusion Criteria:

• Fully understand the study and voluntarily sign the informed consent form;
• Male or female, 18-70 years of age;
• Histologically or cytologically confirmed diagnosis of advanced solid tumors, in whom the available standard treatments failed;
• Must have at least 1 measurable lesion per RECIST v1.1;
• Eastern Cooperative Oncology Group performance status of 0 or 1;
• Life expectancy ≥ 3 months;
• All adverse events from prior treatment have either returned to baseline or CTCAE v5.0≤Grade 1;
• Both male and female participants (unless postmenopausal, surgical sterilization) and partners must agree to use a reliable form of contraception during the study treatment period and for at least 6 months after the last dose of the study drug.

Exclusion Criteria:

• Medical history, computed tomography (CT) or magnetic resonance imaging (MRI) results indicate the existence of the central nervous system (CNS) metastases；

• Uncontrollable third cavity effusion requiring repeated drainage, which was judged by the investigator to be unsuitable for study;

• The main organ function meets any of the following criteria within 7 days prior to treatment:

  • Hematological function: absolute neutrophil count (ANC) < 1.5 × 10^9/L, platelet (PLT) < 75 × 10^9/L, or hemoglobin (Hb) < 100 g/L;
  • Hepatic function: alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≥ 3 × upper limit of normal (ULN), ALT and AST ≥ 5×ULN for patients with liver metastases; total bilirubin (TBIL) ≥ 1.5×ULN; albumin < 30 g/L;
  • Blood cholesterol > 300 mg/dL or > 7.75 mmol/L;
  • Creatinine clearance (Cockcroft-Gault formula) < 50 mL/min;
  • International normalized ratio (INR) > 1.5 or activated partial thromboplastin time (APTT) > 1.5×ULN;

• Any other malignancy within 5 years;

• Abnormal thyroid function with clinical symptoms or diabetes, which cannot be controlled by available treatments;

• History of autoimmune disease, including but not limited to systemic lupus erythematosus, nephritis, psoriasis, rheumatoid arthritis, inflammatory bowel disease, autoimmune hepatitis;

• Previous immune checkpoint inhibitors induced ≥ Grade 2 immune-related adverse reactions in vital organs, including but not limited to myocarditis and central nervous system toxicity; rapidly tumor progressed after previous PD-1 inhibitor treatment;

• Interstitial lung disease, non-infectious pneumonitis, and radiation-induced pneumonia with symptoms and/or requiring steroids for treatment;

• Received prior allogeneic stem cell transplantation or solid organ transplantation;

• Active infection within 1 week before the first administration currently requires systemic anti-infective therapy;

• Known allergy to other mAbs or any antibody excipient, severe allergic reaction to humanized antibodies or fusion proteins, and history of anaphylactoid reaction or other hypersensitivity reactions;

• Known history of diagnosed neurological or mental disorders, for example, epilepsy, dementia, etc.;

• Patients were deemed unsuitable for participating in the study by the investigator for any reason.