This is a phase Ia/Ib, open-label, multiple-dose, dose-escalation and expansion study to evaluate the safety, tolerability, pharmacokinetics and anti-tumor activity of CS1001 in subjects with advanced solid tumors.

Inclusion Criteria:

1. With advanced-stage or metastatic tumor (unresectable) and experienced progression since last anti-tumor treatment; standard therapy is not available or rejected.
2. ECOG performance status of 0 or 1.
3. Subjects must have at least one measurable lesion.
4. Patients with life expectancy ≥ 3 months.
5. Subject must have adequate organ function.
6. Fertile men and women of childbearing potential must agree to use an effective method of birth control from providing signed consent and for six months after last study drug administration.

Exclusion Criteria:

1. Known brain metastasis or other CNS metastasis that is either symptomatic or untreated.
2. Subjects with active autoimmune diseases or history of autoimmune diseases should be excluded.
3. Patients who have received immune checkpoint proteins/antibody/medicine (including PD-1, PD-L1, etc) for treatment.
4. Known history of HIV infection.
5. Hepatitis B surface antigen (HBsAg) and Hepatitis B core antibody (HBcAb) positive or Hepatitis C virus (HCV) antibody positive.
6. Patients who have serious hypersensitive reaction to monoclonal antibodies, and have history of uncontrolled allergic asthma.
7. Known history of alcoholism or drugs abuse.

For more information regarding trial participation, please contact at cstonera@cstonepharma.com