The TETRAS upper limb score is calculated as the sum of the 6 separate upper-limb maneuvers assessed by the clinician: forward-outstretched postural tremor \[right\], forward outstretched postural tremor \[left\], lateral wing-beating postural tremor \[right\], lateral wing-beating postural tremor \[left\], kinetic tremor \[right\], kinetic tremor \[left\], each on a 0 (no tremor) to 4 (maximum tremor) severity scale in 0.5-point increments. TETRAS Part 4 score for both upper limbs ranged from 0 to 24, higher scores indicated more severe tremor. A negative change from baseline indicated less tremor. Baseline is defined as the last non-missing value collected prior to receiving first dose of study drug. Change from baseline will be defined as assessment value minus baseline value.

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. Incidence and Severity of Adverse Events have been reported.

Vital signs parameters included body temperature, pulse rate, respiratory rate, blood pressure (systolic and diastolic), clinical laboratory measures (chemistry, hematology, urinalysis, and coagulation), electrocardiogram parameters (heart rate, PR, QRS, QT, and corrected QT intervals). Any change in vital sign abnormalities that was clinically significant in the medical and scientific judgment of the investigator and not related to an underlying disease was reported as an unsolicited adverse event (AE). Any clinically significant abnormality associated with underlying disease does not require reporting as an (S)AE unless judged by the investigator to be more severe than expected for the participant's condition.

The C-SSRS is described as a scale developed at Columbia University that has 2-6 questions each in categories of Suicidal Ideation, Intensity of Ideation, Suicidal Behavior, and Actual Attempts. Four constructs were measured. Severity of Suicidal ideation is rated on a 5-point ordinal scale. Intensity of ideation is comprised of 5 items (frequency, duration, controllability, deterrents, and reason for ideation), each rated on a 5-point ordinal scale. Suicidal behavior is rated on a nominal scale that includes actual, aborted, and interrupted attempts; preparatory behavior; and non-suicidal self-injurious behavior. Lethality, assesses actual attempts; actual lethality is rated on a 6-point ordinal scale, and if actual lethality is 0, potential lethality of attempts is rated on a 3-point ordinal scale.The higher the C-SSRS score, the higher the suicide risk (ie. worse outcome).