A Study of SHR-1707 With Mild Cognitive Impairment Due to Alzheimer's Disease or Mild Alzheimer's Disease

Prior treatment

• Patients who had severe trauma or had undergone surgery within 6 months prior to screening, or were scheduled to undergo surgery during the trial;
• History of hypoglycemic coma or uncontrolled diabetes 6 months prior to the screening period;
• Had unstable or clinically significant cardiovascular disease within 1 year prior to the screening period, had or currently has atrial fibrillation;
• Patients with clinically significant systemic immunosuppression due to the persistent effects of immunosuppressive drugs;
• According to the investigators, the subjects were suicidal or had committed suicidal behavior in the six months before the screening period;
• A woman who is pregnant, or a woman of childbearing potential whose pregnancy test results are positive, or who is breastfeeding; or has a plan to have a child, unwilling or unable to take effective contraceptive measures within 30 days prior to the screening period or six months after the last use of the investigational drug;
• Three months prior to the randomization period or planned to use dual antiplatelet or anticoagulant drugs during the trial;
• Received any passive immunotherapy or other long-acting biologics used to prevent or delay cognitive decline within 1 year prior to screening;

Other illness

• Cognitive impairment of subjects due to other medical or neurological factors (other than AD);
• History of stroke or transient ischemic attack, seizures, or other unexplained loss of consciousness within the past year;
• Any psychiatric diagnosis that may interfere with the subject's cognitive assessment;
• Cannot tolerate MRI or has contraindications to MRI, has significant lesions shown on MRI during screening, or has other conditions that the investigator believes may bring a significant risk to the subject;
• Suspected allergy to Aβ antibody drugs and excipients;
• History of moderate (3b) or severe renal failure or insufficiency;
• Uncontrolled hypertension: systolic blood pressure \> 160 mmHg and diastolic blood pressure \>100 mmHg in supine position during screening or baseline;
• History of malignancy within 5 years prior to screening;
• Human immunodeficiency virus antibody (HIV-Ab), treponema pallidum antibody and hepatitis C virus antibody (HCV-Ab) were positive during screening. Hepatitis B active subjects (Hepatitis B virus surface antigen (HBsAg) positive with HBV DNA \> upper limit of normal);
• coagulation disorders;
• Severe visual or hearing impairment, unable to cooperate with the completion of the scale;
• History of drug abuse or addiction;

Lab values

• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) exceeding 3 times ULN, or total bilirubin exceeding 2 times ULN;

Other

• 12-lead ECG showed QTcF \> 450ms for male and \> 470ms for female during screening;
• Thyroid dysfunction;
• Folic acid or vitamin B12 below the lower limit of normal;
• Investigators and relevant staff of the research Centre or others directly involved in programme implementation;
• The investigator considers that there are any circumstances that would cause the subject to be unable to complete the study or pose a significant risk to the subject or other factors that would interfere with the subject's ability to complete the study evaluation.

• Age ≥ 55 and ≤ 85 on the date of signing the informed consent, males or females;
• BMI ≥ 19 kg/m2 and ≤ 32 kg/m2, weight ≥ 45 kg and ≤ 100 kg at screening or baseline;
• Must meet the diagnostic criteria for MCI due to AD or mild AD;
• The total score of HAMD-17 should be ≤ 10 scores at screening and baseline;
• The score of Hachinski ischemic scale should be ≤ 4 scores at screening and baseline;
• Qualitative amyloid PET scan results from the central laboratory confirmed the presence of pathological changes in AD;
• Agreed to test ApoE genotype;
• Have a stable caregiver; where symptomatic drugs for AD is used, they must be stable for at least 3 months prior to the baseline visit.