An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; Initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent were events between first dose of study drug up to the follow up visit (up to 47 days in Part A, 29 days in Part B and C), that were absent before treatment or that worsened relative to pretreatment state.

A full physical examination included head, ears, eyes, nose, mouth, skin, heart and lung examinations, lymph nodes, gastrointestinal, musculoskeletal, and neurological systems. Abnormality in physical examinations was based on investigator's discretion.

The neurological examination included the assessment of higher cortical function, the cranial nerves, motor function, deep tendon reflexes, sensory exam, and coordination and gait. Abnormality in neurological examinations was based on investigator's discretion.

C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("Yes" on "wish to be dead", "non-specific active suicidal thoughts", "active suicidal ideation with methods without intent to act or some intent to act, without specific plan or with specific plan and intent, any self-injurious behavior with no suicidal intent). In this outcome measure, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any non-suicidal self-injurious behavior, at baseline were reported.

C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("Yes" on "wish to be dead", "non-specific active suicidal thoughts", "active suicidal ideation with methods without intent to act or some intent to act, without specific plan or with specific plan and intent, any self-injurious behavior with no suicidal intent). In this outcome, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any self-injurious behavior, at day 7 were reported.

C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("Yes" on "wish to be dead", "non-specific active suicidal thoughts", "active suicidal ideation with methods without intent to act or some intent to act, without specific plan or with specific plan and intent, any self-injurious behavior with no suicidal intent). In this outcome, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any self-injurious behavior, at Day 14 were reported.

C-SSRS is a questionnaire to assess suicidal ideation and suicidal behavior. C-SSRS assessed whether participant experienced following: completed suicide; suicide attempt (response of "Yes" on "actual attempt"); preparatory acts toward imminent suicidal behavior ("Yes" on "preparatory acts or behavior", "aborted attempt" or "interrupted attempt"), suicidal ideation ("Yes" on "wish to be dead", "non-specific active suicidal thoughts", "active suicidal ideation with methods without intent to act or some intent to act, without specific plan or with specific plan and intent, any self-injurious behavior with no suicidal intent). In this outcome, number of participants with positive response (response of "yes") to suicidal behavior, ideation or any self-injurious behavior, at Day 19 were reported.

Criteria for clinically significant ECG abnormalities: maximum PR interval \>=300 milliseconds (msec) and maximum PR interval increase from baseline (IFB): percent change (Pctchg) \>=25 percent (%) for baseline value of \>200 msec and Pctchg\>=50% for baseline value of \<=200 msec for PR interval, maximum QRS interval \>=140 msec and a maximum IFB: Pctchg\>=50%, maximum QTCF interval (Fridericia's Correction) of 450 msec to \<480 msec, 480 msec to \<500 msec or \>=500 msec and a maximum change of \<=30 change \<60 or \>=60 msec from baseline.

Abnormalities criteria:hematology(hemoglobin; hematocrit; RBC\<0.8\*lower limit of normal \[LLN\]; platelets\<0.5\*LLN,\>1.75\*upper limit of normal \[ULN\]; WBC\<0.6\*LLN,\>1.5\*ULN; lymphocytes; neutrophils; basophils; eosinophils; monocytes\<0.8\*LLN,\>1.2\*ULN; coagulation(prothrombin (PT); PT ratio\>1.1\*ULN), liver(bilirubin\>1.5\*ULN; aspartate aminotransferase; alanine aminotransferase; alkaline phosphatase; gamma GT\>0.3\*ULN; protein; albumin\<0.8\*LLN,\>1.2\*ULN); renal(blood urea nitrogen, creatinine\>1.3\*ULN; uric acid\>1.2\*ULN); electrolytes(sodium\<0.95\*LLN,\>1.05\*ULN; potassium; chloride; calcium; bicarbonate\<0.9\*LLN,\>1.1\*ULN), chemistry(glucose\<0.6\*LLN,\>1.5\* ULN); urinalysis(pH \<4.5,\>8; glucose, ketones, protein, blood, urobilinogen, nitrite, bilirubin, leukocyte, esterase\>1; WBC; bacteria\>=20, epithelial cells\>=6; granular casts, hyaline casts, red cell casts, white cell casts\>1; lipids(cholesterol\[C\], LDL-C\>1.3\*ULN; HDL-C\<0.8\*LLN, triglycerides\>1.3\*ULN); hormones(T4, T3, T4, TSH\<0.8\*LLN,\>1.2\*ULN)

Following parameters were analyzed for examination of vital signs: supine systolic and diastolic blood pressure, pulse rate and body temperature.

Continuous cardiac telemetry was conducted in participants. All abnormal cardiac rhythms were recorded and reviewed by the study physician for the presence of rhythms of potential clinical concern. In this outcome measure, number of participants who had cardiac rhythms of potential clinical concern (based on physician's discretion) were reported.