Alzheon'sCEO of Framingham, Mass-based Alaheon, told BioSpace that his company's drug was designed to inhibit the formation of toxic soluble amyloid oligomers. It's the oligomers that are the key driver of Alzheimer's disease. Data collected by the company shows that if you target the oligomers, there is a chance to arrest the disease.
Theory lines up with Promis, they are getting ready to go to phase 3 clinical studies. Some interesting artilcles on there website.