Inclusion Criteria:
Inclusion Criteria for All Participants:
* Healthy as determined by medical evaluation, including medical and psychiatric history, physical and neurological examinations, ECG, vital sign measurements, and laboratory test results, as evaluated by the investigator.
* Body mass index of 18.5 to 35.0 kilograms per square meter (kg/m\^2), inclusive, and a total body weight ≥50 kilograms (kg) (110 pounds \[lbs\]).
Inclusion Criteria for Part A:
* Male and female (women of nonchildbearing potential only) participants, ages 18 to 55 years, inclusive, at the time of signing the informed consent form (ICF).
Inclusion Criteria for Part B:
* Male and female (women of nonchildbearing potential only) participants, ages 18 to 55 years, inclusive, at the time of signing the ICF.
Inclusion Criteria for Part C:
* Male and female (both women of childbearing and nonchildbearing potential) participants, ages 18 to 55 years, inclusive, at the time of signing the ICF.
* Sexually active women of childbearing potential must agree to use at least an acceptable birth control method during the trial and for 7 days after the last dose of IMP. Acceptable birth control methods that result in a failure rate of more than 1% per year include the following:
* Progestogen-only oral hormonal contraception, where inhibition of ovulation is not the primary mode of action
* Male or female condom with or without spermicide
* Cap, diaphragm, or sponge with spermicide
Exclusion Criteria for All Participants:
* Current or past history of significant cardiovascular, pulmonary, gastrointestinal, renal, hepatic, metabolic, genitourinary, endocrine (including diabetes mellitus, thyroid disorders), malignancy, hematological, immunological, neurological, or psychiatric disease that, in the opinion of the investigator or medical monitor, could compromise either participant safety or the results of the trial.
* "Yes" responses for any of the following items on the C-SSRS (within the individual's lifetime):
* Suicidal Ideation Item 3 (Active Suicidal Ideation With Any Methods \[Not Plan\] Without Intent to Act)
* Suicidal Ideation Item 4 (Active Suicidal Ideation With Some Intent to Act, Without Specific Plan)
* Suicidal Ideation Item 5 (Active Suicidal Ideation With Specific Plan and Intent)
* Any of the Suicidal Behavior items (Actual Attempt, Interrupted Attempt, Aborted Attempt, or Preparatory Acts/Behavior)
* "Yes" responses for any of the following items on the C-SSRS (within past 12 months):
* Suicidal Ideation Item 1 (Wish to be Dead)
* Suicidal Ideation Item 2 (Non-Specific Active Suicidal Thoughts)
* Serious risk of suicide in the opinion of the investigator is also exclusionary.
* Any condition or surgery that could possibly affect drug absorption, including, but not limited to, bowel resections, bariatric weight loss surgery/procedures, gastrectomy, and cholecystectomy.
* Positive result for human immunodeficiency virus (HIV) antibody, hepatitis B surface antigen, hepatitis B total core antibody, or hepatitis C antibody with detectable viral ribonucleic acid (RNA) levels at Screening.
* Positive drug screen (including cotinine and tetrahydrocannabinol \[THC\]) or a positive test for alcohol.
Exclusion Criteria for Part A:
* History of presence of any of the following and deemed clinically significant by the investigator or designee and confirmed by the medical monitor:
* Ventricular dysfunction or risk factors for torsades de pointes (e.g., heart failure, cardiomyopathy, family history of long-QT syndrome)
* Any of the following clinical laboratory test results at the Screening Visit or Check-in (Day -1), which can be confirmed by a single repeat measurement, if deemed necessary:
* Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) \> upper limit of normal (ULN).
* Total bilirubin \>ULN. If Gilbert's syndrome is suspected, total bilirubin \>ULN is acceptable if the conjugated or direct bilirubin fraction is \<20% of total bilirubin.
* Hypokalemia (potassium levels \< lower limit of normal \[LLN\] millimoles per liter \[mmol/L\]), and/or hypomagnesemia (magnesium levels \<1.2 milligrams per deciliter \[mg/dL\]; \<0.5 mmol/L), and/or hypocalcemia (corrected serum calcium \<8.0 mg/dL or ionized calcium \<1.0 mmol/L).
Exclusion Criteria for Part B:
* Participants positive for human leukocyte antigen (HLA)-B\*1502 or HLA-A\*3101.
* Family history of drug reaction with eosinophilia and systemic symptoms (DRESS).
* Family history of porphyria.
* History of cardiac conduction disturbance including second- and third-degree atrioventricular heart block.
* Any of the following clinical laboratory test results at the Screening Visit or Check-in (Day -1), which can be confirmed by a single repeat measurement:
* Platelets, white blood cell count, absolute neutrophil count, or hemoglobin \ULN.
* Total bilirubin \>ULN. If Gilbert's syndrome is suspected, total bilirubin \>ULN is acceptable if the conjugated or direct bilirubin fraction is \<20% of total bilirubin.
Exclusion Criteria for Part C:
* Any of the following clinical laboratory test results at the Screening Visit or Check-in (Day -1), as assessed by the central laboratory and confirmed by a single repeat measurement, if deemed necessary:
* AST or ALT ≥2 × ULN.
* Total bilirubin \>1.5 × ULN. If Gilbert's syndrome is suspected, total bilirubin \>1.5 × ULN is acceptable if the conjugated or direct bilirubin fraction is \<20% of total bilirubin.
* Female participants who are pregnant, breastfeeding, or planning to become pregnant during IMP treatment or within 7 days after the last dose of IMP. Women of childbearing potential must have a negative serum pregnancy test result at the Screening Visit and a negative urine pregnancy test result at Check-in.
\[Note: Other inclusion and exclusion criteria as per protocol may apply.\]
