The Study of Safety and Preliminary Efficacy of ALT001 in Patients With MultIple System Atrophy-Cerebellar Type

This is a single-center, prospective, randomized, open-label, blinded outcome assessment (PROBE) study. At the end of the PROBE study, patients who have completed the study may opt to enter the open-label extension (OLE) study. The objective of the study is to evaluate the safety, tolerability and potential preliminary efficacy of ALT001 in the treatment of patients with multiple system atrophy-cerebellar type (MSA-C).

Inclusion Criteria: * 1\. Age between 30 and 75 years inclusive, either sex; * 2\. Clinically established or clinically probable MSA-C as defined by the 2022 MDS diagnostic criteria for multiple system atrophy; * 3\. Duration of MSA-C-related motor symptoms, including ataxia, no longer than 5 years; * 4\. Score ≤ 3 on Item 14 of the Unified Multiple System Atrophy Rating Scale (UMSARS) Part II (motor examination); * 5\. Estimated life expectancy ≥ 1 year as assessed by the investigator; * 6\. Voluntary participation in this study and provision of written informed consent Exclusion Criteria: * 1\. Presence of other diseases that may cause ataxia at screening (e.g., infectious diseases, immune-mediated diseases, tumors, paraneoplastic conditions, hereditary disorders, trauma, nutritional deficiencies, toxic exposure, or other neurodegenerative diseases); * 2\. Dementia indicated by the Mini-Mental State Examination (MMSE) at enrollment (score ≤17 for illiterate individuals, ≤20 for primary school education, or ≤24 for junior high school or above) or a prior definitive diagnosis of dementia; * 3\. Evidence of other central nervous system pathologies on brain MRI at screening suggesting a diagnosis of neurodegenerative diseases other than MSA; or other significant pathological findings on brain MRI at screening, including but not limited to: cerebral hemorrhage, acute cerebral infarction, aneurysm, vascular malformation, infectious lesions, brain tumors, or other space-occupying lesions (meningiomas or arachnoid cysts with a maximum diameter \