Alzheimer's disease (AD) is an irreversible, progressive neurological disorder that slowly destroys memory and thinking skills, and eventually the ability to carry out the simplest tasks. AD affects people in all parts of the world, with age being the biggest risk factor. The incidence of AD is one in ten over the age of 65, one in two by age 90.

ß-amyloid (Aß) is considered to be the major toxic species in AD. There are two major forms of Aß: Aß 40 and Aß 42. Aß accumulates in the brain in AD in plaques and coating cerebrovascular vessels.

Cenna is developing novel disease-modifying drugs for Alzheimer's disease, which inhibit the production of Aß in the brain.