IMB-071703

IMB071703 injection is a recombinant bifunctional antibody fusion protein independently developed by Beijing Immune Ark Pharmaceutical Technology Co., Ltd. It is an immune activator for the tumor microenvironment, targeting CD137 (4-1BB) and CD40 respectively. It can bind to the CD40 receptor on the surface of APC to activate the CD40 signaling pathway; bind to the CD137 receptor on the surface of T cells to activate the 4-1BB signaling pathway, while connecting APC and T cells to promote the proliferation and activation of specific T cells. Based on the FcγR binding defect method, it reduces side effects but retains a high anti-tumor activity of activated DCs and T cells. Main purpose: To evaluate its safety and tolerability in the treatment of subjects with recurrent or metastatic advanced malignant solid tumors; To determine the MTD and/or RP2D; Secondary purpose: To evaluate its PK characteristics in the treatment of subjects with recurrent or metastatic advanced malignant solid tumors; To evaluate its immunogenicity in the treatment of subjects with recurrent or metastatic advanced malignant solid tumors; To evaluate its preliminary anti-tumor activity in subjects with recurrent or metastatic advanced malignant solid tumors using RECIST V1.1. Exploratory purpose: Use iRECIST to evaluate its preliminary anti-tumor activity in subjects with recurrent or metastatic advanced malignant solid tumors (iRECIST evaluation is used only after RECIST V1.1 evaluation of PD); Evaluate its PD characteristics in subjects with recurrent or metastatic advanced malignant solid tumors.