Inclusion Criteria:
1. Patients who voluntarily sign the informed consent form, understand the study and are willing to follow and able to complete all study procedures,
2. Male or female, 75 ≥ age ≥ 18 years,
3. Patients enrolled in Phase Ib are those with histopathologically or cytologically confirmed metastatic or unresectable locally advanced, recurrent solid tumors (ovarian cancer, cervical cancer, renal cancer, head and neck cancer, etc.) who have failed to respond to or are intolerant to standard treatment regimens or have no standard effective treatment regimen, and at least one evaluable lesion meeting the definition of RECISTv1.1,
4. Patients enrolled in Phase II must have at least 1 measurable lesion consistent with the definition of RECISTv1.1 and need to meet one of the following tumor types: a).histologically and/or cytologically confirmed diagnosis of advanced renal cancer, head and neck cancer, or cervical cancer who have failed at least 1 line of prior therapy with PD-1 and anti-PD-1/PD-L1 antibodies alone or in combination with chemotherapy; failure of anti-PD-1/PD-L1 antibodies is defined as disease progression after achieving complete response (CR) or partial response (PR) with anti-PD-1/PD-L1 antibodies alone or in combination with chemotherapy, or disease progression after ≥ 6 months of stable disease (SD); b). histologically and/or cytologically confirmed diagnosis of ovarian cancer who have received 1 line of prior therapy consisting of at least 1 platinum agent and imaging evidence of disease progression within 6 months of the last dose of platinum-based chemotherapy,
5. Patients who have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1,
6. Patients who have a life expectancy of at least 3 months,
7. Patients who are ≥ 4 weeks after receiving anti-tumor therapy, such as chemotherapy, radiotherapy, biotherapy, endocrine therapy and immunotherapy before the first dose of study drug,
8. Patients need to have appropriate organ and hematopoietic function, laboratory tests，
9. Male and female patients of childbearing potential should agree to use effective contraception from the signing of the informed consent form until 3 months after the last dose.
Exclusion Criteria:
1. Patients with clinically symptomatic central nervous system metastases and/or carcinomatous meningitis,
2. Patients who have previously failed to recover from adverse reactions to CTCAE V5.0 grade ≤ 1,
3. Uncontrolled stable systemic disease with treatment，
4. Any active autoimmune disease or documented autoimmune disease, or systemic syndrome previously requiring systemic steroids or immunosuppressive drugs，
5. Patients who require systemic corticosteroids (at doses equivalent to \> 10 mg prednisone/day) or other immunosuppressive drugs within 14 days before enrollment or during the study，
6. History of infection with human immunodeficiency virus, or other acquired, congenital immunodeficiency diseases, or history of organ transplantation, or stem cell transplantation，
7. Patients who have pulmonary tuberculosis and are in active phase at screening，
8. Patients with active chronic hepatitis B or active hepatitis C，
9. Patients who have received anti-4-1BB target drugs，
10. Known subjects who have previously treated with macromolecular protein agents/monoclonal antibodies, or known to have a serious allergic reaction to any component of the test drug (CTCAE V5.0 grade greater than 3)，
11. Patient plan to have major surgery during this study including a 28-day screening period，
12. Severe infection within 4 weeks before the first dose,Or patients with active infection requiring intravenous antibiotics within the first 2 weeks,
13. Patient participated in other clinical trials of drugs within 4 weeks before enrollment and have been enrolled in drug therapy, or did not reach 4 weeks after the end of treatment (EOT),
14. Patient had a history of alcoholism, drug abuse or drug abuse within the past 1 year,
15. Patien had ≥ grade 3 irAEs or ≥ grade 2 immune-related myocarditis in previous immunotherapy,
16. Patient had a history of other primary malignancies ,
17. Patient had a history of moderate or severe dyspnea at rest due to advanced malignancies or their complications or severe primary lung disease, or currently required continuous oxygen therapy, or currently had interstitial lung disease (ILD) or pneumonia,
18. Patient received live attenuated vaccines within 4 weeks before the first dose or planned to receive during the study,
19. Patient had a clear history of neurological or psychiatric disorders, such as epilepsy, dementia, and poor compliance,
20. Patient was pregnant or lactating women; Eligible patients of childbearing potential (men and women) did not agree to use a reliable method of contraception during the trial and for at least 3 months after the last dose, and female patients of childbearing age had a positive blood or urine pregnancy test within 7 days before enrollment,
21. Patients who were considered by the investigator to be unsuitable for participation in the trial for other reasons.
