CD47 x PHD2

Primary objectives: 1) To evaluate the safety and tolerability of SG404 for injection in patients with advanced malignant tumors. 2) To determine the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of intravenous SG404 for injection in patients with advanced malignant tumors, and to provide a basis for the dosing regimen and dosage of Phase II clinical trials. Secondary objectives: 1) To evaluate the pharmacokinetic characteristics of SG404 for injection in patients with advanced malignant tumors. 2) To evaluate the pharmacodynamic characteristics of SG404 for injection in patients with advanced malignant tumors. 3) To evaluate the immunogenicity of SG404 for injection in patients with advanced malignant tumors. 4) To preliminarily evaluate the efficacy of SG404 for injection in patients with advanced malignant tumors. Exploratory objectives: To explore biomarkers in tumor tissues that may potentially predict the efficacy of SG404 for injection.