APOE and Alzheimer disease: It was found to selectively and strongly inhibit Aβ42 oligomer formation and the subsequent amyloid aggregation without binding to plaques.133–136 In a phase 2 study in AD patients, tramiprosate was found to pass the BBB and reduce Aβ42 levels in a dose-dependent manner.137 In a phase III clinical study conducted on mild to moderate AD patients, tramiprosate showed significant efficacy in APOE4/4 homozygotes, and intermediate efficacy in APOE4 heterozygotes.