This is a multi-center, double-blind study that will evaluate 265 mg twice daily (BID) of ALZ-801, an oral tablet, over 78 weeks as a treatment for subjects (50-80 years old) with Early AD who are homozygous for the ε4 allele of the apolipoprotein gene (APOE4 homozygous or APOE4/4). The primary efficacy outcome assessment is a measure of cognition (ADAS-cog 13). Additional measures of global and functional impairments will also be assessed. Imaging and soluble biomarkers of AD and neurodegeneration will be measured and a sub-study to evaluate cerebrospinal fluid (CSF) biomarkers is also included.