Merck & Co has terminated a Phase II/III trial testing its investigational medicine verubecestat in patients with mild to moderate Alzheimer's disease.
The move came after an external data monitoring committee determined that there was "virtually no chance of finding a positive clinical effect" in the EPOCH study, which was evaluating the efficacy and safety of two oral doses of verubecestat administered once-daily versus placebo in patients with mild-to-moderate AD currently using standard of care treatment.
However, it also noted that safety signals observed did not warrant stopping the study, and recommended that the Phase III APECS trial, which is assessing the drug in people with prodromal Alzheimer's disease, continue as planned. Results from this study are expected in February 2019.
"While we are disappointed that a benefit was not observed in this study, our work continues with APECS, which is studying verubecestat in people with less advanced disease," noted Dr Roger Perlmutter, president of Merck Research Laboratories.
Verubecestat is an investigational small molecule inhibitor of the beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), which is believed to play a key role in the production of the amyloid beta that accumulates in the brain to form amyloid plaques in patients with the disease.
Evidence suggests that inhibiting BACE could reduce amyloid plaque formation and modify the progression of Alzheimer's disease, and several other drugmakers - including Lilly and Novartis - have investigational drugs targeting this mechanism.
Results from EPOCH will be analysed and presented at an upcoming scientific meeting, Merck noted.