The search for an Alzheimer's disease treatment has been unsuccessful for the past 14 years.
The latest failure came in September, when Axovant said it failed a key late-stage trial for its drug, intepirdine.
Alzheimer's affects more than 5 million Americans, a number that's expected to balloon to 13.8 million by 2050. There are only four drugs that have been approved to treat the symptoms of the disease, and the most recent drug approval happened in 2003.
2017 in particular has been a tough year for Alzheimer's failures. In February alone, Lundbeck discontinued two of its trials, Merck discontinued one of its studies, and Accera failed a late-stage trial as well.
Axovant's trial results are the last major results to come out in 2017, with the next ones reading out in 2018 and a major wave of results expected in 2019.