AC Immune SA is a clinical-stage biopharmaceutical company, which engages in the discovery and development of therapeutic and diagnostic products for neurodegenerative diseases. It leverages proprietary technology platforms to discover, design, and develop novel, proprietary medicines for prevention, diagnosis, and treatment of neurodegenerative diseases associated with protein misfolding. The company was founded by Jean-Marie Lehn, Claude Nicolau, Roscoe Brady, Fred van Leuven, Ruth Greferath, Andrea Pfeifer, and Alexey V. Eleesiv on February 13, 2003 and is headquartered in Lausanne, Switzerland.