Pepinemab (VX 15/2503) is a human monoclonal antibody against SEMA4D, a signalling protein 4D (SEMA4D), also known as CD100, which is a regulator of neuronal development and plays a role in a variety of cellular processes. Pepinemab can be used in the study of various neurodegenerative diseases such as Alzheimer's disease by blocking the activity of SEMA4D.