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

Inclusion Criteria:

1. Subjects with metastatic or locally advanced unresectable solid tumor, who progressed following treatment with all available standard therapy, or for whom treatment is not available, not tolerated or refused.
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 180 days 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 prior therapies targeting PD-1, PD-L1, or CTLA-4.
4. Known history of HIV infection.
5. Subjects with active Hepatitis B or C infection.
6. Any unresolved CTCAE Grade ≥ 2 toxicities from prior anti-cancer therapy with the exception of vitiligo, alopecia.
7. Patients who have serious hypersensitive reaction to monoclonal antibodies, and have history of uncontrolled allergic asthma.
8. Known history of alcoholism or drugs abuse.
9. Subjects who received organ transplantation.
10. Known psychiatric disorders that would interfere with cooperation with the requirements of the trial.
11. Female subjects who are pregnant or breast-feeding; Male or female subjects of childbearing potential who refuse to use an effective method of birth control.

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