AC Immune S.A. (ACIU) Stock Analysis & Winston Score

AC Immune is a Swiss biotech company focused on developing drugs to treat brain diseases caused by misfolded proteins, most notably Alzheimer's disease. Its main work involves creating therapies and diagnostics that target toxic protein clumps — like amyloid and tau — that build up in the brain. The company partners with large pharmaceutical companies, including Roche and Eli Lilly, rather than selling directly to patients. AC Immune makes money primarily through research collaboration agreements, milestone payments, and licensing deals with its big pharma partners, not from selling approved products. It is headquartered in Lausanne, Switzerland, and operates as a clinical-stage company, meaning it has no commercial drug on the market yet. Its 100% gross margin reflects the nature of partnership revenue, but its deeply negative operating margin shows it spends far more on research than it earns. The biggest risk is clinical trial failure — if its pipeline drugs do not prove effective or safe, the company's value could drop sharply.