Alzheimer's disease (AD) is an extremely challenging and often frustrating area of drug discovery. Since the withdrawal of tacrine (Cognex) in 2006, more than 200 AD drug candidates have failed in late-stage clinical trials.[1] The antihistamine drug dimebon (1, Figure 1) belongs to this long list. In 2008, 1 attracted considerable interest within the AD community when it successfully completed a small six-month clinical trial in Russia, in ...