Safety and Effect on Memory of PYM50028 in Mild Alzheimer's Disease

Inclusion Criteria: * At least 50 years of age * Diagnosis of possible or probable Alzheimer's disease * Mini mental state examination score at least 16 * Good understanding of both written and verbal English * A recent head scan that is consistent with the diagnosis of Alzheimer's disease Exclusion Criteria: * Recent history or clinical evidence of significant neurological disease other than dementia due to Alzheimer's disease * Known to have another condition that is associated with dementia * Use of psychotropic medication within the previous 4 weeks (excluding cholinesterase inhibitors, selective serotonin reuptake inhibitors and venlafaxine) * Hormone replacement therapy started or changed within the previous 6 months * Received any investigational drugs within the previous 12 weeks