Experimental: Intervention group

Intrathecal administration combined with intravenous administration of Aleeto of Aleeto was given to each MSA patient in the intervention group, with intrathecal administration on days 1, 31 and 61 and intravenous administration on days 2 to 14, 32 to 44±3 and 62 to 74±5, and treatment was given once a day.~intrathecal administration: 8 mL sodium chloride injection + Aleeto (130 μg/branch) for intrathecal administration, which was completed in about 5 minutes; intravenous administration: Aleeto (130 μg/branch) was dissolved in 100 ml sodium chloride injection, which was completed in about 30-40 minutes. After completion of the above treatments and 90±7 days of follow-up, all subjects entered the OLE study phase. During this period, all participants were given the option of continuing to receive 3 phases (on Days 91 to 104±7, Days 121 to 134±7, and Days 151 to 164±7) of intravenous Aleeto administration (14 consecutive days of Aleeto 130 μg qd i.v. in each phase).

No_intervention: Control group

Each MSA patient in the blank control group received only basic treatment with no trial-related treatment.~After completion of the above treatments and 90±7 days of follow-up, all subjects entered the OLE study phase. During this period, all participants were given the option of continuing to receive 3 phases (on Days 91 to 104±7, Days 121 to 134±7, and Days 151 to 164±7) of intravenous Aleeto administration (14 consecutive days of Aleeto 130 μg qd i.v. in each phase).