A Phase I Clinical Study to Evaluate the Safety, Tolerability and Pharmacokinetics of Anti-PD-1 Antibody (HLX10) in Combination With Avastin Biosimilar (HLX04) in Patients With Advanced Solid Tumors

Inclusion Criteria: 1. Age ≥18 years, male or female 2. Patient with histologically or cytologically confirmed advanced malignant solid tumors who have failed standard of care, or has no standard-of-care therapy or are not suitable for standard of care at the present stage; 3. Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1； 4. Life expectancy greater than 3 months; 5. Patient must have at least one measurable tumor lesion as defined by RECIST v1.1; the lesion concerned must not be a bone metastasis if only one target lesion is present; 6. Has adequate organ functions; 7. If the subject is a patient with hepatocellular carcinoma, Child-Pugh classification must be A. 8. A qualified patient (male or female) of childbearing potential must agree to use reliable contraceptive methods (hormonal, or barrier method or abstinence) for the course of the study and through at least 6 months after the last dose; a female patient of childbearing potential must have negative blood pregnancy test within 7 days prior to enrollment; 9. The subject must give his/her informed consent to this study prior to the trial, and voluntarily sign a written informed consent form. Exclusion Criteria: 1. Histopathological confirmed head and neck cancer or squamous-cell lung cancer, or bleeding tendency in the tumor lesion judged by the investigator; 2. Has received antitumor therapy like radiotherapy, chemotherapy, targeted therapy, endocrinal therapy or immunotherapy, or other clinical study drug therapy within 4 months prior to the initial drug administration; 3. Has received a surgical operation on major viscera or experienced apparent trauma within 4 weeks from the initial drug administration, or experienced subcutaneous venous access device implantation within 7 days; 4. The adverse reactions which occurred in the previous antitumor treatment were not recovered to ≤ grade 1 based on CTCAE 4.03 assessment (except for hair loss); 5. Evidences of metastatic lesion in the patient's central nervous system; 6. Previously experienced ≥ grade 3 immune-related adverse event during immunotherapy; 7. Active, or history of autoimmune disease which may relapse (for example, systemic lupus erythematosus, rheumatoid arthritis, vasculitis, etc.); 8. Currently having or have had interstitial lung disease; 9. Uncontrollable active infection(s); 10. History of immunodeficiency, including HIV antibody positive; 11. Known active hepatitis B; or hepatitis C virus infections; 12. Has bleeding tendency; 13. History of severe cardiovascular diseases; 14. Known gastrointestinal diseases as follows: Gastrointestinal perforation, abdominal fistula or abdominal abscess within 6 months before signing the informed consent; History of poorly controlled or recurrent inflammatory bowel disease; Active peptic ulcers, or \> moderate esophageal varices; 15. Known hypersensitivity to Bevacizumab, or other anti-PD-1, anti-PD-L1 monoclonal antibody agents; 16. Pregnant or breastfeeding female.