4,500 mild–moderate AD patients randomized to placebo and 0.5mg/kg i.v. every 13 weeks for 18 months in APOE4 carriers, and randomized to placebo, 0.5, 1.0mg/kg i.v. every 13 weeks for 18 months in APOE4 noncarriers in 4 trials (ClinicalTrials.gov identifiers lNCT00575055, NCT00574132, NCT00676143, NCT00667810). Trials were halted after completion of 2 trials demonstrated a failure to meet primary outcome measures on ADAS-cog and activities of daily living.109. The gene discussed is APOE; the disease is Alzheimer disease.