The purpose of this trial is to examine the safety and pharmacokinetics of NPC-22 administered in a single ascending dose in healthy adult males.

The healthy adult males will be randomized into six arms, and will receive single dose of NPC-22 (five doses, placebo)

Inclusion Criteria:

1. Subjects who have provided their own written informed consent
2. Subjects aged ≥20 and <40 years at the time of informed consent
3. Subjects with body weight of ≥50 kg and body mass index (BMI) (kg/m2) of ≥18.5 and <25.0
4. Subjects who were identified to have no health problem on physical examination, physical assessment, laboratory tests, or other examinations at screening by the principal investigator or a sub-investigator

Exclusion Criteria:

1. Subjects with a complication or a history of drug abuse (use of an illicit drug) or alcohol dependence
2. Subjects with a history of severe disease that may recur during the study period
3. Subjects with any concurrent illnesses
4. Subjects who received another study drug within 180 days prior to the start of study drug administration
5. Subjects who donated blood of ≥400 mL within 12 weeks, blood of ≥200 mL within 4 weeks, or blood components within 2 weeks prior to the start of the study
6. Subjects who used any medicinal product (including over the counter drugs except for topical products) or similar product like a dietary supplement (including health food) within 7 days prior to the start of study drug administration
7. Subjects who took any food or beverage containing grapefruit or St. John's wort within 7 days prior to the start of study drug administration
8. Subjects who took any alcohol or caffeine-containing beverage within 3 days prior to the start of study drug administration
9. Subjects who smoked within 90 days prior to the start of study drug administration, or do not agree to stop smoking during the study period
10. Subjects who had a positive result for HBs antigen, HCV antibody, or HIV antigen/antibody, or a positive reaction to syphilis serology or urine drug test at screening
11. Subjects who are unsuitable as a subject in this study in the judgement of the principal investigator or a sub-investigator based on the 12-lead electrocardiogram at screening [e.g., Fridericia's corrected QT (QTcF) interval of ≥450 ms]
12. Subjects who have a familial history of torsades de pointes or long QT syndrome
13. Subjects who are unsuitable as a subject in this study in the judgement of the principal investigator or a sub-investigator by having a deviation from the institutional reference values
14. Subjects who are unsuitable as a subject in this study in the judgement of the principal investigator or a sub-investigator due to other reasons