For decades, biopharmaceutical researchers have worked tirelessly in the pursuit of new treatments and cures for the costly and devastating Alzheimer’s disease. Advancing treatments for Alzheimer’s is a top priority for biopharmaceutical companies who are investing billions in the development of new therapies and working collaboratively with the Alzheimer’s community on basic research. Despite this perseverance, Alzheimer’s remains one of the most vexing scientific and medical challenges of our time.

A recent PhRMA report found that between 1998 and 2014 a total of 123 medicines to treat Alzheimer’s disease were halted and four were approved. These daunting numbers demonstrate biopharmaceutical companies’ level of commitment to Alzheimer’s disease research but also the enormity of the challenge.

Researchers are exploring many promising, new approaches to treating and preventing Alzheimer’s disease. One example is a new class of potential medicines called BACE inhibitors which target the beta-secretase, or BACE, enzyme that breaks down amyloid precursor protein to form beta amyloid, a sticky protein fragment integral to Alzheimer’s disease.

A new feature by Amgen explains the history, promise and challenges of targeting BACE. After scientists isolated the BACE enzyme in the 1990s, they had to find a molecule small enough to cross the blood brain barrier that protects the brain but large enough to interact effectively with the BACE protein. Needless to say, it also had to show a high level of safety. This process sent researchers back to the drawing board several times. Then they had to find new ways to diagnose the disease, so they could get the potential medicine to the right people. Having done that, researchers would have to prove, through many years of testing, that the molecule is safe and effective for patients.

Today, several companies are getting close to doing just that. In the United States, five BACE inhibitors are in late stage development. The Alzheimer’s community is watching these trials closely and the many others taking new approaches to fight this terrible disease.

Learn more about how the biopharmaceutical sector is fighting Alzheimer’s here.