The primary purpose of this study is to assess biomarker known as amyloid beta peptide 40 (Ab40) in Cerebrospinal Fluid (CSF), following a single oral dose of PAZ-417 in subjects with Alzheimer Disease (AD). This study will also consider another biomarker amyloid beta peptide 42 (Ab42) in Cerebrospinal Fluid in subjects with Alzheimer Disease and assess the safety, tolerability and pharmacokinetic profile of PAZ-417 in both plasma and Cerebrospinal Fluid in these subjects.