BACE1 and Alzheimer disease: However, even though BACE1 inhibitors efficiently lower brain Aβ levels [48, 59, 60], so far two clinical trials with mild-to-moderate AD patients failed due to unspecific side effects [60] or lack of efficacy, as documented by the recent failure of the phase 2/3b EPOCH trial of verubecestat (ClinicalTrials.gov identifier NCT01739348).