Few diseases have been as difficult for drug companies to conquer as Alzheimer’s. The five existing therapies treat symptoms of the memory-robbing condition, not the disease itself. And between 2002 and 2012, a staggering 99.6% of drugs in development failed. We’re betting that 2016 will deliver the long overdue breakthrough that changes that: A medicine that actually slows the progression of Alzheimer’s. Though it’s not a perfect treatment, Eli Lilly’s (LLY) solanezumab—a drug 15 years in the making—will pass muster in clinical tests and be well on its way to FDA approval, as a therapy for mild Alzheimer’s, by year’s end.

This article is part of the 2016 Fortune Crystal Ball, a package of 33 predictions about business, politics and the economy by the writers and editors of Fortune. To see the entire package, click here.