UMSARS - clinician-rated scale comprised of 4 parts: Part I (Historical Review), Part II (Motor Examination), Part III (Autonomic Examination), Part IV (Global Disability Scale). Modified UMSARS is composed of subset of 9 items from original UMSARS Part I and Part II. Responses are measured on 4-point scale ranged from 0-3, where 0= no/mild impairment, 1= moderate impairment, 2= severe impairment, 3=complete impairment. Total modified UMSARS score is sum of these 9 items, score range from 0 to 27. Higher scores indicate greater impairment.

An adverse event (AE) is defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in participants or clinical investigation participants administered an investigational (medicinal) product and that does not necessarily have a causal relationship with this treatment. A serious AE (SAE) is defined as any event that met any of the following criteria at any dose: death; life-threatening; inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect in the offspring of a participant who received study drug; other important medical events that may not have resulted in death, be life-threatening, or required hospitalization, or, based upon appropriate medical judgment, they may have jeopardized the participant and may have required medical or surgical intervention to prevent one of the other serious outcomes.