Prothena Corporation is a late-stage clinical biotechnology company that discovers and develops novel therapies for diseases caused by protein dysregulation, particularly neurodegenerative conditions and rare peripheral amyloid diseases caused by alpha-synuclein, tau, and other misfolded proteins. The company operates a partnership-driven business model, licensing its clinical-stage therapeutic candidates to major pharmaceutical partners (Roche, Novo Nordisk, and Bristol Myers Squibb) in exchange for upfront payments, development-stage milestone payments, and tiered royalties on future product sales; simultaneously, the company invests in early-stage discovery programs, including its proprietary CYTOPE® platform that enables targeting of intracellular disease pathways previously considered undruggable. Prothena's pipeline targets large patient populations with serious, life-threatening conditions—including Parkinson's disease, ATTR amyloidosis, Alzheimer's disease, and ALS—where current therapies address only symptoms or have limited efficacy, thereby positioning the company to capture substantial royalty revenue should its partnered candidates reach the market.