Merck & Co's BACE1 inhibitor verubecestat has shown promise in a Phase I trial assessing its potential in Alzheimer's disease.

The randomised, double-blind, placebo-controlled multiple dose study assessed the safety and tolerability, pharmacokinetics and pharmacodynamic profile of the drug in 32 patients with mild-to-moderate forms of the disease.

The data, published in the peer-reviewed journal Science Translational Medicine, show that at doses of 12mg, 40mg and 60mg verubecestat caused a dose-dependent and sustained reduction in the levels of amyloid β 42 from baseline in the cerebral spinal fluid, a measure of BACE1 activity, of 57 percent, 79 percent and 84 percent, respectively.

On the safety side, there were no study discontinuations due to adverse events, while analysis of vital signs and laboratory assessments, including liver function tests, showed no statistically significant changes related to the administration of verubecestat, the firm said.

BACE1 is an enzyme that plays a central role in the production of toxic amyloid beta peptide production in the brain, and thus represents a potential target for therapeutic intervention to slow progression of the disease.

"The development of a potential disease modifying therapy for treatment of Alzheimer's disease has long been a focus of biomedical research," noted Dr Michael Egan, vice president, clinical development neurosciences, Merck Research Laboratories. "We believe this research has the potential to contribute important evidence regarding the amyloid hypothesis, a leading scientific theory for what causes Alzheimer's disease, and we look forward to seeing the data from our ongoing Phase III clinical trials."

The efficacy and safety of verubecestat is currently being evaluated in two pivotal Phase III clinical trials, EPOCH and APECS, for the treatment of mild-to-moderate AD and prodromal AD, respectively.