A Study to Evaluate the Effects of Therapeutic and Supratherapeutic Doses of KRP-S124 Compared to Placebo With Moxifloxacin on QTc Interval in Healthy Participants

Inclusion Criteria:

• Male or non-childbearing potential female, non-smoker (no use of tobacco or nicotine products within 3 months prior to screening), greater than or equal to (>=) 18 and less than or equal to (<=) 55 years of age, with body mass index (BMI) greater than (>) 18.5 and less than (<) 30.0 kilograms per square meter (kg/m^2) and body weight >=50.0 kilograms (kg) for males and >=45.0 kg for females.
• Female participants of non-childbearing potential should not donate ova for 90 days after the last dose.
• Male participants (including men who have had a vasectomy) with a pregnant partner must agree to use a condom from the first dose and for 90 days after the last dose.
• Male participants must be willing not to donate sperm for 90 days after the last dose.
• Able to understand the study procedures and provide signed informed consent to participate in the study.

Exclusion Criteria:

• Any clinically significant abnormal finding at physical examination at screening or Baseline (Day -1 of Period 1).
• Clinically significant abnormal laboratory test results or positive serology test results for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibody, or human immunodeficiency virus (HIV) antigen and antibody at screening.
• Any of the following laboratory parameters above the upper limit of normal (ULN) values at Screening or Baseline (Day -1 of Period 1): alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl-transpeptidase (GGT), direct bilirubin and total bilirubin. Only abnormal values between 1-1.5 * ULN may be repeated once for confirmation to below ULN.
• Known allergic reactions to KRP-S124 or other related drugs, or to any excipient in the formulation.
• Clinically significant vital signs abnormalities (systolic blood pressure lower than 90 or over 140 millimeters of mercury [mmHg], diastolic blood pressure lower than 50 or over 90 mmHg, or heart rate less than 50 or over 100 beats per minute [bpm]) at screening or Baseline (Day -1 of Period 1).
• History of drug abuse within 1 year prior to screening or recreational use of soft drugs (such as marijuana) within 1 month or hard drugs (such as cocaine, phencyclidine [PCP], crack, opioid derivatives including heroin, and amphetamine derivatives) within 3 months prior to screening.
• History of alcohol abuse within 1 year prior to screening or regular use of alcohol within 6 months prior to screening that exceeds 10 units for women or 15 units for men of alcohol per week (1 unit = 340 mL of beer 5 percent (%), 140 mL of wine 12%, or 45 mL of distilled alcohol 40%).
• Participation in a clinical research study involving the administration of an investigational or marketed drug or device within 30 days prior to the first dosing (or 5 half-lives, whichever is longer), administration of a biological product in the context of a clinical research study within 90 days prior to the first dosing (or 5 half-lives, whichever is longer), or concomitant participation in an investigational study involving no drug or device administration.
• History of sustained and non-sustained cardiac arrhythmias (ECG demonstrated), family history of sudden cardiac death, and history of additional risk factors for Torsade-de-pointes, (e.g. [for example]: heart failure, hypokalemia, unexplained syncope, family history of Long QT Syndrome).
• Any reason which, in the opinion of the Investigator, would prevent the participant from participating in the study.