Safety, Efficacy and Dose Titration of Sodium Oligo-mannurarate Capsule on Mild to Moderate Alzheimer's Disease

• Improvement of Clinician's Interview-Based Impression of Change Plus(CIBIC-plus) of sodium oligo-mannurarate capsule [ Time Frame: 4 weeks, 12 weeks, 24 weeks ] [ Designated as safety issue: No ]
• Improvement of Alzheimer's Disease Cooperative Study/Activities of Daily(ADCS-ADL) of sodium oligo-mannurarate capsule [ Time Frame: 4 weeks, 12 weeks, 24 weeks ] [ Designated as safety issue: No ]
• Improvement of Neuropsychiatric Inventory(NPI) of sodium oligo-mannurarate capsule [ Time Frame: 4 weeks, 12 weeks, 24 weeks ] [ Designated as safety issue: No ]
• β-Amyloi 40 [ Time Frame: 0 week, 24 weeks ] [ Designated as safety issue: No ]
  Cerebrospinal fluid will be assayed in part of the patients, about 10%.
• β-Amyloi 42 [ Time Frame: 0 week, 24 weeks ] [ Designated as safety issue: No ]
  Cerebrospinal fluid will be assayed in part of the patients, about 10%.
• Total Tau Protein [ Time Frame: 0 week, 24 weeks ] [ Designated as safety issue: No ]
  Cerebrospinal fluid will be assayed in part of the patients, about 10%.
• Phosphorylated Tau Protein [ Time Frame: 0 week, 24 weeks ] [ Designated as safety issue: No ]
  Cerebrospinal fluid will be assayed in part of the patients, about 10%.
• Glucose metabolism of bilateral temporoparietal cortex [ Time Frame: 0 week, 24 weeks ] [ Designated as safety issue: No ]
  Obtained by Positron Emission Tomography in two sites.
• Apolipoprotein E Genotype [ Time Frame: -4 weeks ] [ Designated as safety issue: No ]
  To research the change of Aβ40、Aβ42、T-tau、P-tau and glucose metabolism of bilateral temporoparietal cortex in patients of different apoE genotype.

• Improvement of Clinician's Interview-Based Impression of Change Plus(CIBIC-plus) of sodium oligo-mannurarate capsule [ Time Frame: 4 weeks, 12 weeks, 24 weeks ] [ Designated as safety issue: No ]
• Improvement of Alzheimer's Disease Cooperative Study/Activities of Daily(ADCS-ADL) of sodium oligo-mannurarate capsule [ Time Frame: 4 weeks, 12 weeks, 24 weeks ] [ Designated as safety issue: No ]
• Improvement of Neuropsychiatric Inventory(NPI) of sodium oligo-mannurarate capsule [ Time Frame: 4 weeks, 12 weeks, 24 weeks ] [ Designated as safety issue: No ]

The primary purpose of this study is to determine whether sodium oligo-mannurarate capsule is effective and safe in the treatment of mild to moderate alzheimer' disease, and to determine the best therapeutic dose of sodium oligo-mannurarate capsule.

Alzheimer's disease is known for placing a great burden on caregivers which includes social, psychological, physical or economic aspects. Research indicates that the disease is associated with plaques and tangles in the brain. Currently used treatments offer a small symptomatic benefit. No treatments to delay or halt the progression of the disease are, as of yet, available. The investigators suppose sodium oligo-mannurarate capsule to be effective to halt the progression of the disease.

• Alzheimer Disease
• Cognitive Impairment

• Drug: Sodium oligo-mannurarate 600mg
  sodium oligo-mannurarate capsule 600mg twice a day for 24 weeks
  Other Name: Sodium oligo-mannurarate low dose
• Drug: Sodium oligo-mannurarate 900mg
  sodium oligo-mannurarate capsule 900mg twice a day for 24 weeks
  Other Name: Sodium oligo-mannurarate high dose
• Drug: Placebo
  simulant of sodium oligo-mannurarate capsule

• Experimental: sodium oligo-mannurarate 900mg
  Intervention: Drug: Sodium oligo-mannurarate 900mg
• Experimental: sodium oligo-mannurarate 600mg
  Intervention: Drug: Sodium oligo-mannurarate 600mg
• Placebo Comparator: Placebo
  Intervention: Drug: Placebo

Inclusion Criteria:

• At least primarily educated.
• Accord with Probable Alzheimer disease of National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association(NINCDS-ADRDA)'s Criteria.
• 10 points ≤ Minimum Mean-Square Error(MMSE) ≤ 24 points.
• Hachinski ischemia scale ＜4 points.
• Hamilton depression scale ≤10 points.
• Should have stable accompanying person, or at least contact 2 hours per day, 4 days per week with accompanying person. The accompanying person should help the patient throughout the trial.
• Signed the information consent form.

Exclusion Criteria:

• Have been in other clinical trials within 30 days before this trial' start.
• women during pregnancy or lactation.
• Dementia caused by other diseases.
• previous nervous system diseases.
• Abnormal laboratory results.
• Uncontrolled hypertension.
• Unstable or serious diseases of heart, lung, liver, kidney and blood.
• Visual or auditory handicap.
• Significant focal lesions revealed by electronic computer X-ray tomography(CT) or magnetic resonance imaging(MRI) in one year before enrollment.
• Alcohol abuse or drug abuse.
• psychotic, including patients with serious depression.
• Patients being in drug therapy of Alzheimer disease which cannot be stopped.
• In treatment of heparin, Polysaccharide sulfate, mannose ester 3 weeks before the recruitment.
• Investigator consider the patient cannot finish this trial for any reason.
• Relatives or employees of the investigators, staff of the investigate centers, contract research organization and sponsor.