Merck (MRK 0.25%) recently announced positive Phase 1b clinical study results for its experimental Alzheimer's disease drug  MK-8931. This compound belongs to a broader class of experimental Alzheimer's treatments called BACE inhibitors, and AstraZeneca (AZN 0.39%) and Eli Lilly (LLY 0.54%) have also explored drugs in this class. In the following video, health-care analyst Max Macaluso discusses the latest results, why shares of Merck didn't move significantly on the news, and also takes a look at the broader BACE inhibitor space.