The study was designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of CSPCHA131 alone or plus chemotherapy in patients with advanced solid tumors.

This is a dose escalation and expansion study with the aim to evaluate and characterize the tolerability and safety profile of CSPCHA131 alone (Stage I) or plus chemotherapy (Stage II) in patients with advanced solid tumors.

Inclusion Criteria:

• 1.18-75 years of age.
• 2. Histologically or cytologically confirmed diagnosis of advanced or metastatic malignant solid tumors, for which standard therapy either does not exist or has been proven ineffective or intolerable for the patient.
• 3. At least one measurable tumor lesion according to RECIST version 1.1.
• 4. ECOG performance status of 0 or 1.
• 5. Life expectancy ≥ 3 months. No cardiac insufficiency or serious abnormalities in the electrocardiogram at baseline.

Exclusion Criteria:

• 1. Administration of chemotherapy, radiotherapy, biotherapy, endocrine therapy, targeted therapy, immunotherapy, other anti-tumor treatments or an investigational drug within 4 weeks or 5 half-lives, whichever is longer, preceding the first dose of study treatment.
• 2. Have undergone surgery within 4 weeks prior to the study treatment or have not fully recovered from any previous invasive procedure.
• 3. Adverse reactions to previous anti-tumor treatments that levels have not recovered to grade 1 or less.
• 4. Patients with evidence of uncontrolled nervous system metastasis or meningeal metastases, in the opinion of the investigator, not suitable for enrollment.
• 5. Active infections of grade 2 or above.
• 6. Peripheral neuropathy of grade 2 or above.