Trial of Verubecestat for Prodromal Alzheimer Disease Discontinued

doctor and patient talking
doctor and patient talking
Merck announced the discontinuation of the Phase 3 APECS study for the treatment of AD.

Merck announced the discontinuation of the Phase 3 APECS study (protocol 019) evaluating verubecestat (MK-8931) for the treatment of patients with prodromal Alzheimer disease. 

APECS was a randomized, placebo-controlled, parallel-group, double-blind study (N=1350) that enrolled patients aged 50–85 years with prodromal Alzheimer disease. They were randomized to verubecestat 12mg, verubecestat 40mg or placebo once daily. The primary efficacy outcome was the change from baseline in the Clinical Dementia Rating Scale-Sum of Boxes (CDR-SB) score following 104 weeks of treatment. 

Verubecestat is a small molecule inhibitor of the beta-site amyloid precursor protein cleaving enzyme (BACE1). The decision to halt the study came after review of the overall benefit and risk associated with the drug during an interim safety analysis. The Data Monitoring Committee concluded that it was unlikely that positive benefit/risk for investigational verubecestat could be established if the study continued. 

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Findings from the APECS study will be announced at a future medical meeting. 


Merck announces discontinuation of APECS study evaluating verubcestat (MK-8931) for the treatment of people with prodromal Alzheimer’s disease [press release]. Kenilworth, NJ: Merck. Published February 13, 2018. Accessed February 22, 2018.

This article originally appeared on MPR