NC527-X (Zhejiang Haibo Biotechnology, 04690d)

NC527-X is an investigational **bispecific monoclonal antibody** designed to target both **B7-H3** (also known as **CD276**) and **4-1BB** (also known as **TNFRSF9**). B7-H3 is a member of the B7 family of immune checkpoint proteins that is frequently overexpressed in various malignant solid tumors, where it inhibits T-cell activation and contributes to immune evasion. 4-1BB is a co-stimulatory receptor expressed on activated T cells and NK cells. By simultaneously binding to B7-H3 on tumor cells and 4-1BB on immune cells, NC527-X is intended to provide localized 4-1BB agonism—thereby minimizing systemic toxicity—while concurrently blocking B7-H3-mediated immunosuppression. This dual mechanism aims to enhance the anti-tumor immune response specifically within the tumor microenvironment. Developed by **Zhejiang Haibo Biotechnology**, NC527-X is currently undergoing Phase 1 clinical evaluation (e.g., CTR20244235) to assess its safety, tolerability, and pharmacokinetics in healthy volunteers and patients with advanced malignant solid tumors.