Food effect part:

To investigate the effect of food on the pharmacokinetics of RTA 402 and evaluate the safety of RTA 402 in Japanese healthy male adults, using the capsule formulations.

Caucasian subject part:

To investigate the pharmacokinetics of a single dose of RTA 402 administered in the fasted state and compare the pharmacokinetics with those observed in Japanese healthy male adults in the food effect part

Inclusion Criteria:

1) Written voluntary informed consent to participate in the study; 2) [Food Effect Part] Japanese men 20 to <40 years of age at informed consent; [Caucasian Subject Part] Caucasian men 20 to <40 years of age at informed consent; 3) BMI 18.5 kg/m2 to <25.0 kg/m2 at screening

Exclusion Criteria:

1. Presence of any disease requiring treatment;
2. History of heart failure (e.g., history of diagnosis of congestive heart failure categorized as Class III or IV of the New York Heart Association (NYHA) Functional Classification or history of hospitalization due to heart failure);
3. Alcoholism or drug addiction, or any positive result on drug abuse testing;
4. History of or current drug allergy;
5. Any positive result on infectious disease testing. Individuals who are positive for active antibodies produced by hepatitis B vaccination and are not infected with hepatitis B virus at screening can be enrolled in the study;