A Study of QL1706H in Patients With Advanced Solid Tumors

Inclusion Criteria:

* Subjects participate voluntarily and sign informed consent.
* Patients with Pathologically confirmed metastatic or recurrent malignant solid tumors, failure or intolerance of at least first-line treatment and unsuitable for radical treatment such as surgery
* Subject has at least one measurable lesion according to RECIST (V1.1) evaluation criteria.
* Eastern Cooperative Oncology Group (ECOG) score was 0 or 1.
* The extension of life is more than 3 months
* Vital organs' function is adequate for enrolling
* Subjects agree to use effective contraceptive measures.Women who have not been pregnant or breastfeeding.
* Before the first use of the investigational drug, all the reversible toxicity of the previous antitumor therapy returned to ≤1 (according to CTCAE V5.0),Excluding any grade of hair loss and pigmentation, grade 2 or less peripheral sensory neuropathy, and other abnormalities that the investigator and/or sponsor assessed to outweigh the risk of toxicity.

Exclusion Criteria:

* Active autoimmune diseases that exist within 2 years prior to the first use of the investigational drug and require systemic treatment.
* There are known past grade 3 or 4 immune-related adverse events associated with antitumor immunotherapy.
* Symptomatic central nervous system (CNS) metastasis, pia metastasis or spinal cord compression due to metastasis prior to signing informed consent.
* Subjects with any of the following cardiovascular diseases that seriously endanger the safety of the subjects or affect the completion of the study
* Subjects with diseases that are planned to be treated with systemic corticosteroids or other immunosuppressive drugs during the study period
* Prior treatment with cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) inhibitor combined with programmed cell death protein-1 (PD-1) inhibitor, or CTLA-4 inhibitor combined with PD-L1 inhibitor.
* Had received chemotherapy, targeted therapy, biotherapy, endocrine therapy, immunotherapy and other anti-tumor treatments within 4 weeks before the first use of experimental drugs
* Subjects with positive antibodies to HIV;Treponema pallidum antibody positive;HBsAg positive patients with VIRAL DEoxy ribonucleic acid (HBV DNA) \>2000 IU/ mL or 10\^4 copy number/mL should receive antiviral therapy according to local treatment guidelines and be willing to receive antiviral therapy throughout the study period.Hepatitis C virus antibody positive and viral ribonucleic acid (HCV RNA) positive