Alzheimer's drug manufacturing is a growing industry and is creating a vast competitive market for well-known drug companies. Novartis is the newest company to increase its standing in the market and work toward developing new technology to fight the disease. Currently, they sell a drug named Exelon that helps to preserve a brain chemical that assists with learning and memory. That drug alone will have almost $930 million in sales this year. In addition, Novartis bought a license to a vaccine for Alzheimer's and just recently completed a trial for the drug in December 2012. Novartis will need to continue to invest research, time, and money to gain the competitive advantage in this particular medical arena. However, other companies distributed three failed drugs within the last year, allowing Novartis a platform on which to make headway and achieve market dominance. Baxter International Inc. distributed one of those failed drugs, "Gammagard," which showed no improvment in patients who received the drug. In addition, Eli Lilly manufactured two drugs that failed within the last year. One of the reasons those drugs may have failed is because they focused mainly on preventing build-up of brain plaque called "amyloid," as the theory is that clearing that plaque will prevent cognitive decline. Researchers contend that it may not be enough to focus on this build-up of brain material, but rather it is necessary to encourage therapies that target "tau proteins." The differences in opinion on what therapies and drugs are best to treat Alzheimer's fuels the competition and makes the market unattractive for some companies that are wary of the difficulties posed by this disease. Novartis is willing to navigate those difficulties in hopes of achieving the advantage in a market potentially worth $20 billion.