Trial to Evaluate the Efficacy and Safety of KM-819 Treatment to Slow the Progression of Multiple System Atrophy (MSA)

Inclusion Criteria:

1. Must be diagnosed as probable or possible MSA, according to the second consensuscriteria for diagnosis of MSA

2. Patients who are able to visit the clinic during the study period to be in thestudy.

3. ≥ 30 years and ≤ 80 years of age at the time of signing the Informed Consent

4. Antiparkinsonian medications should be stable for, at least, one month beforeenrollment.

5. Body Mass Index (BMI) range of 18.5 to 30 kg/m^2 inclusive at Screening

6. Patient agrees to use acceptable contraceptive methods during the study

7. For women, menopause, sterilization confirmed.

8. For childbearing women, older than 40, and agreed with more than 2 methods ofcontraception below and agreed with no desire to be pregnant during and after thestudy, and, agreed with maintaining medically acceptable methods of contraceptionduring for 90 days after the study.

9. Cognitive ability for possible to make self-decision, understand and follow theinstruction, to make written signature on consent form.

10. If no ability to walk, patients must be accompanied by caregiver by wheelchair onschedule.

Exclusion Criteria:

1. A diagnosis of drug induced parkinsonism by typical neuroleptic treatment orhaloperidol medication.

2. Women who are pregnant or lactating

3. History of suicide attempt. Any recent suicidal ideation (a level of 4 or 5) withinthe last 3 months prior to Day 1, or has a positive response ('Yes') to eitherquestion 4 or 5 of the Columbia Suicide Severity Rating Scale (C-SSRS) at check-in (Day 1), or who is at significant risk to commit suicide, as judged by theInvestigator using the C-SSRS at Screening.

4. Febrile illness or symptomatic viral, bacterial (including upper respiratoryinfection) or fungal (non-cutaneous) infection.

5. Any clinically significant abnormality following the Investigator's review of thephysical examination and protocol-defined clinical laboratory tests at Screening orsite check-in.

6. Patient has a mean pulse rate < 40

7. Patient has a mean corrected QT interval using Fridericia's formula (QTcF) of > 430msec (for males) and > 450 msec (for females).

8. History of unexplained syncope, cardiac arrest, unexplained cardiac arrhythmias ortorsade de pointes, structural heart disease or a family history of Long QTSyndrome.

9. Positive serology test for hepatitis B surface antigen (HBsAg), anti-hepatitis Avirus (HAV), immunoglobulin M (IgM), anti-hepatitis C virus (HCV) or anti-humanimmunodeficiency virus (HIV).

10. Known or suspected hypersensitivity to KM-819, or any components of theformulation(s) used.

11. Patient has a serious medical or surgical condition.

12. Patients unable to understand the consent form, and determined by investigator withtoo serious problems for participating in the study.

13. Patients unable to visit the clinical site on schedule due to the no abilitymobilize.

14. Patients who had brain surgery history.