BACE1 and Alzheimer disease: Several BACE1 inhibitors have reached phase III clinical trials, such as verubecestat [21], atabecestat [22], lanabecestat [23], LY3202626 [24], and umibecestat [25], but these drugs have failed due to a lack of efficacy or worse cognitive function in patients with mild cognitive impairment (MCI), and mild to moderate AD [143].