This excerpt taken from the TPTX 10-K filed Mar 29, 2007.
Current Treatments for Alzheimers Disease
Despite limited effectiveness, acetylcholinesterase inhibitors are the mainstay treatment option for Alzheimers disease. Four acetylcholinesterase inhibitors are approved for the symptomatic improvement of mild to moderate Alzheimers disease: Aricept, the market leader, Exelon, Razadyne (formally Reminyl), and Cognex. One additional product, Namenda, a compound with a different mechanism of action, is approved for symptomatic improvement in patients with moderate to severe Alzheimers disease.