This is a Phase 1, open-label, dose escalation study in patients with advanced/metastatic solid tumors. Study drug, ADG116, is an anti -CTLA-4 fully human monoclonal antibody that specifically binds to human CTLA-4. ADG106, a fully human ligand-blocking agonistic anti-CD137 IgG4 mAb, is expected to enhance the activity of activated T cells. The enhanced antitumor efficacy results observed from the preclinical studies of ADG116 in combination with ADG106 or anti-PD-1 provided further support to explore such combinations in clinical settings for better patient responses.

Inclusion Criteria:

Patients must meet all of the following inclusion criteria to be eligible for participation in this study:

1. ≥ 18 years of age at the time of informed consent.
2. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
3. Patients with advanced or metastatic solid tumors, who have progressed after all standard therapies, or for whom no further standard therapy exists.
4. At least 1 measurable lesion at baseline according to the definition of RECIST v1.1.
5. Adequate organ function.

Exclusion Criteria:

• Patients who meet any of the following criteria cannot be enrolled:

1. Pregnant or breastfeeding females.
2. Childbearing potential who does not agree to the use of contraception during the treatment period..
3. Treatment with any investigational drug within washout period.
4. Grade ≥ 3 immune-related AEs (irAEs) or irAE that lead to discontinuation of prior immunotherapy.
5. Central nervous system disease involvement
6. History or risk of autoimmune disease.
7. History of life-threatening hypersensitivity or known to be allergic to protein drugs or recombinant proteins or any ingredients contained in the ADG116 drug formulation.
8. Patients requiring systemic treatment with corticosteroids
9. Patients receiving granulocyte colony stimulating factor (G-CSF), within 14 days prior to the first dose of the study drug.
10. Any uncontrolled active infections requiring systemic antimicrobial treatment (viral, bacterial, or other), or uncontrolled or poorly controlled, asthma, chronic obstructive pulmonary disease (COPD).
11. Major surgery within 4 weeks prior to the first dose of the study drug.
12. Has had an allogeneic tissue/solid organ transplant.