This is a phase 1b/2, open label study to evaluate the safety, tolerability, pharmacokinetics and initial efficacy of KD6001 in combination with Tislelizumab ± Bevacizumab in patients with Advanced HCC and Other Solid Tumors.

Main Inclusion Criteria:

1. Being voluntary to sign the informed consent form.

2. Male or female, aged ≥ 18 years.

3. Patients whose estimated survival time is more than 3 months.

4. Eastern Cooperative Oncology Group (ECOG) performance status score 0 or 1.

5. At least one measurable lesion is used as the target lesion according to the Response Evaluation Criteria in Solid Tumors Version 1.1(RECIST V1.1).

6. Histologically or cytologically confirmed advanced solid tumors. Have a current liver function meeting Child Pugh Class A in patients with HCC.

   Part A: Advanced solid tumors. PartB/C: HCC.

7. Patients will agree to provide tumor tissue samples.

8. The results of laboratory examination during the screening period suggest that the subjects have good organ function.

9. Male subjects with reproductive ability or female subjects with the possibility of pregnancy use effective contraceptive methods.

10. Good compliance and follow-up.

Main Exclusion Criteria:

1. History of malignancy other than the disease under study within 5 years prior to screening，except those malignancies that are expected to be cured after treatment.
2. Systematic treatment with antitumor drugs within 4 weeks prior to the start of this study.
3. Prior treatment with anti-CTLA-4 antibody.
4. Adverse events caused by prior treatment did not recovered to NCI-CTCAE v5.0 grade 1 and below.
5. Subjects with CNS metastases or leptomeningeal disease.
6. Subjects with an active, known or suspected autoimmune disease.
7. Subjects with acute or chronic active hepatitis B or hepatitis C.
8. Has histological or cytological diagnosis of fibrolamellar HCC, sarcomatoid HCC or mixed cholangiocarcinoma.
9. Subjects suffers from severe cardiovascular and cerebrovascular diseases. History or evidence of bleeding diathesis or significant coagulopathy at risk of bleeding.
10. Subjects with an active infection requiring systemic treatment.
11. Known history of testing positive for human immunodeficiency virus (HIV).
12. Subjects known to have active tuberculosis (TB).
13. Pregnant or breastfeeding females.
14. Known to be allergic to KD6001, tislelizumab, bevacizumab or its components.