Investigator Initiated Trial of Galcanezumab Treatment in Alzheimer's Disease

Inclusion Criteria: 1. Age between 50 and 90 years at enrollment, regardless of gender; 2. Meeting the NIA-AA core clinical criteria for probable Alzheimer's disease; 3. Clinical Dementia Rating - Global Score (CDR-GS) between ≥1 and ≤2; Clinical Dementia Rating - Memory Box (CDR-Memory box) ≥0.5; 4. Amyloid PET or cerebrospinal fluid (CSF) biomarkers consistent with AD pathology; 5. Mini-Mental State Examination (MMSE) score between ≥12 and ≤26; 6. Non-illiterate or with at least 4 to 6 years of formal education; 7. If currently taking psychiatric or cognitive-enhancing medications, the dosage must have been stable for at least 3 months prior to the study and remain unchanged during the study. Unless otherwise specified, all permitted concomitant medications (non-AD related) must have been stable for at least 4 weeks prior to baseline; 8. Availability of a reliable caregiver or legal guardian able to support the participant throughout the study, defined as spending at least 8 hours per week with the participant; 9. Willingness to participate in the clinical trial, maintain existing interventions during the study period, and provision of signed informed consent. Exclusion Criteria: 1. Presence of neuropsychiatric symptoms outside the typical spectrum of Alzheimer's disease; 2. History of transient ischemic attack (TIA), stroke, or seizure within the past 12 months; 3. Known allergy to gantenerumab or its excipients, or severe allergic reactions to monoclonal antibodies; 4. Cardiovascular or gastrointestinal diseases including severe arrhythmias, uncontrolled hypertension (systolic \>180 mmHg or diastolic \>110 mmHg), or active peptic ulcer disease, inflammatory bowel disease, or other conditions likely to exacerbate gastrointestinal adverse reactions; 5. MRI contraindications such as cardiac pacemaker/defibrillator or ferromagnetic metal implants; 6. MRI evidence of other clinically significant lesions suggesting dementia diagnoses other than AD; 7. MRI findings of other important pathologies, including but not limited to: single hemorrhagic lesions \>10 mm in diameter; evidence of vasogenic edema; brain contusions, softening, aneurysms, vascular malformations, or infectious lesions; strokes involving major vascular territories; severe small vessel or white matter disease; space-occupying lesions; or brain tumors (meningiomas or arachnoid cysts with a maximum diameter \<1 cm may be allowed); 8. Current participation in another clinical trial targeting AD improvement; 9. Any unstable or inadequately controlled medical condition, or other situations deemed by investigators to compromise participant safety or study assessments; 10. Other investigator-determined reasons precluding participant inclusion.