The purpose of this study is to evaluate the efficacy and safety of SK-PC-B70M in patients with mild to moderate Alzheimer's disease.

Inclusion Criteria:

• Clinical diagnosis of probable Alzheimer's disease(DSM-IV and NINCDS-ADRDA criteria)
• MRI within the last 12 months consistent with a diagnosis of AD
• MMSE score of 10 to 26 and CDR of 1 or 2
• AChEI or memantine was not taken at least 3 months prior to screening

Exclusion Criteria:

• Other central nervous disease
• Hypothyroidism, Vitamin B12/ Folic acid deficiency, Hypercalcemia, Neurosyphilis, AIDS
• T.I.A or Major infarction within the last 12 months
• Any serious disorder that could limit the ability of the patient to participate in the study
• COPD or asthma
• Any condition which would make the patient or the caregiver, in the opinion of the investigator, unsuitable for the study