The present study is comprised of two parts: the efficacy estimation part and the key phase II part. In the first part, subjects with unresectable locally advanced or metastatic solid tumors (confirmed by histology or pathology) will be enrolled. Tumor types of special interest include biliary cancers, head and neck cancers, esophageal cancers, sarcoma, and malignant mesothelioma, and at least 8 subjects will be enrolled for each of these tumor types. Subjects with biliary cancers and other tumor types based on the efficacy data of the first part will be enrolled in the second part of the study.~Subjects will receive HX009 via intravenous infusion at 5 mg/Kg once every 2 weeks. Treatment will continue until loss of clinical benefit at the discretion of the investigator, or intolerable toxicity, or withdrawal of consent, or disease progression, or death, or loss of follow-up (whichever occurs first). The maximum duration of treatment with HX009 is one year.~Tumor evaluation is conducted by the investigator according to the Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) and immune RECIST (iRECIST), and is repeated every 6 weeks. Adverse events (AEs) are graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE).
This is a multi-center phase II clinical trial to evaluate the anti-tumor activity and safety of HX009 in subjects with advanced solid tumors.