A Clinical Study of GO306 in Patients With Advanced Solid Tumors

Inclusion Criteria: * Age 18 years old and above, regardless of gender. * Patients with histologically or cytologically confirmed advanced malignant solid tumors, including but not limited to breast cancer, bladder urothelial cancer, colorectal cancer, renal cancer, ovarian epithelial cancer, and neuroendocrine tumors, who have no response or failure to standard treatment (including disease progression and/or intolerable side effects), or no standard treatment. Examples are as follows: * a. Histologically or cytologically confirmed unresectable or metastatic bladder urothelial carcinoma: failure to or intolerance to prior platinum-based chemotherapy and PD-1/PD-L1 inhibitors or no available standard treatment options for unresectable or metastatic disease. * b. Patients with histologically or cytologically confirmed recurrent ovarian cancer with malignant ascites who have received at least one previous line of platinum-based chemotherapy-based therapy and no available standard treatment options, and those with germline or somatic BRCA mutations who failed or did not tolerate PARP inhibitors. * c. Histologically or cytologically confirmed unresectable or metastatic colorectal cancer with liver metastases: failure or intolerance to prior oxaliplatin, fluorouracil, and irinotecan based therapy (or PD-1/PD-L1 inhibitors if the patient is MSI-H/dMMR) or no standard treatment options are available. * d. Patients with histologically or cytologically confirmed unresectable …