LY3022855

LY3022855 (also known as IMC-CS4) is a recombinant human IgG1 monoclonal antibody that targets the colony-stimulating factor-1 receptor (CSF-1R). By binding to CSF-1R, it prevents the interaction with its ligands, CSF-1 and IL-34, thereby inhibiting receptor activation. This mechanism is designed to modulate the tumor microenvironment by reducing the recruitment, proliferation, and survival of tumor-associated macrophages (TAMs), which typically contribute to tumor progression and immune evasion. Developed by Eli Lilly (following the acquisition of ImClone Systems), LY3022855 has been investigated in Phase 1 clinical trials for advanced refractory solid tumors, including metastatic breast cancer and metastatic castration-resistant prostate cancer, both as a monotherapy and in combination with other agents like durvalumab or BRAF/MEK inhibitors.