New Alzheimer's drug signals breakthrough in human clinical trial

© Edgard Garrido
A groundbreaking new drug has been shown to clear away toxic clusters of protein material in the brain thought to be a primary cause of Alzheimer's, suggesting a cure to the disease could soon be a reality.

Alzheimer’s theory suggests the plaque kills the healthy neurons, leading to memory loss. Results from a small Phase 1 study confirm that the drug verubecestat can reduce levels of beta-amyloid, a protein fragment that accumulates in sticky deposits or "plaques" in the brains of Alzheimer's sufferers.

The trial was primarily seeking to determine safety of verubecestat , but found it worked to prevent the production of enzymes that cause plaque on the brain’s neurons.

A study published in Science Translational Medicine by Merck Research Laboratories details the results of the verubecestat trial, which found promising results and importantly, no severe side effects. However, conclusions won’t be drawn until phase III of the clinical trial has been completed, which tests effectiveness and safety on a larger scale.

“It represents well over a decade of investment in this project by many, many scientists,” team leader Matthew Kennedy told Scientific American. “Today there are very limited therapeutic options available for people with Alzheimer’s disease, and those that exist provide only short-term improvement to the cognitive and functional symptoms. They do not directly target the underlying disease processes. There is an urgent need for [these].”

The trial involved giving 32 early-stage Alzheimer’s patients the drug for seven days, with some taking it for two weeks. The short term trial couldn’t render visible changes to the plaques, but fluid samples show reduced levels of the compounds that make up the proteins.

Verubecestat inhibits BACE1 (Beta-site Amyloid precursor protein Cleaving Enzyme 1), an enzyme which produces a protein (amyloid beta) that clumps together and forms the plaques around the neurons, causing Alzheimer's.

Phase III is trialling 2,000 patients with mild to moderate Alzheimer’s and 1,500 in the early stage of the disease. The results are expected in July 2017.