A Study of Bispecific Antibody QLS31901 in Patients With Advanced or Metastatic Malignancies

Inclusion Criteria: 1. Age: 18 to 75 years, male or female. 2. Eastern Cooperative Oncology Group (ECOG) score of 0-1. 3. Life expectancy ≥ 12 weeks. 4. At least one measurable lesion by imaging according to RECIST v1.1 evaluation criteria 5. Patients who failed standard treatment or were absent of standard treatment and have a pathologically confirmed advanced malignant tumor. 6. Sufficient organ function before the first dose of the investigational product Exclusion Criteria: 1. Prior anti-cancer immunotherapy(Those who have received PD1 / PDL1 can be included in this study). 2. Known allergy to the investigational product or any excipient or severe anaphylaxis to other monoclonal antibodies. 3. Received any of the following treatments or drugs prior to the first dose of the study: 4. Symptomatic CNS metastasis, leptomeningeal metastases, or spinal cord compression due to metastasis before signing of the informed consent form. 5. Patients with uncontrollable severe exudation (thoracic cavity, pericardium, abdominal cavity); 6. Presence of active autoimmune disease or has a history of autoimmune disease (including but not limited to: autoimmune hepatitis, interstitial pneumonia, uveitis, enteritis, hepatitis, hypophysitis, vasculitis, nephritis, hyperthyroidism, hypothyroidism \[patients whose condition can be controlled by thyroid hormone replacement therapy can be enrolled\]; Subjects suffer from skin diseases that does not require systemic treatment, such as vitiligo, psoriasis, alopecia, type I diabetes, or childhood asthma that has completely alleviated and does not require any adult intervention can be enrolled. Asthmatic patients requiring bronchodilators for medical intervention cannot be enrolled);