The new medication has been designed to inhibit an enzyme BACE1. The action may lead to a clearing up of amyloid plaques from patients with Alzheimer’s disease. Amyloid plaques are a form of adhesive build-up that can accumulate outside nerve cells. Although amyloid is a protein that is normally found throughout the body, when it is associated with Alzheimer’s disease the protein divides improperly (folding) which creates a form called beta amyloid. This folded protein is considered toxic to neurons in the brain (that is, neural death occurs.)
The reason for focusing on Beta-secretase 1 (or BACE1) is because this enzyme is responsible for the production of beta-amyloid peptides in the brain. The enzyme has become a major target for Alzheimer’s disease researchers.
The new drug, called verbuecestat, has been designed by Dr. Matthew Kennedy, who is the Director of Early Discovery Neuroscience at Merck. The drug has shown some initial success in early studies. Here the drug reduces the sticky peptide beta-amyloid in the blood and cerebrospinal fluid. This was initially tested on rats, and then on monkeys. In addition, some controlled trials have been performed on humans.
With people the research has been part of a phase 1 clinical study involving 32 patients. This was designed to see if the drug was safe and if there were any toxic effects. Following this a phase 3 study commenced and this is currently in progress. The second study involves 2,200 patients who have been diagnosed with mild Alzheimer’s.
The next stage of results reporting is expected in 2017. The research has been published in the journal Science Translational Medicine. The research paper is titled “The BACE1 inhibitor verubecestat (MK-8931) reduces CNS β-amyloid in animal models and in Alzheimer’s disease patients.”