This is a single-center, placebo-controlled, randomized, ascending dose, double-blind study. This study will be evaluating ascending doses of 50, 100, 200, and 400 mg of E6007. This study consists of 5 steps, 1 to 5. In steps 1 to 4 (at ascending doses of 50, 100, 200, and 400 mg), subjects will be randomly assigned in a 6:2 ratio (E6007: placebo) to receive single dose of the study drug under fasted condition. Following 3 days of washout period, subject will receive the study drug once daily for 7 days starting on the fifth day from the single dose administration.

For step 3 (200 mg), subjects will subsequently have at least 17 days of washout period before being escalated to step 5 (200 mg) to receive single dose of E6007 under fed condition, to evaluate food effect of the study drug.

Inclusion criteria

Subjects must meet all of the following criteria to be included in this study:

1. Healthy Japanese male subjects aged 20 to 44 years at the time of informed consent.
2. Has voluntarily consented, in writing, to participate in this study.
3. Has been thoroughly briefed on the conditions for participation in the study, and is willing and able to comply with the conditions.

Exclusion criteria

Subjects who meet any of the following criteria will be excluded from this study:

1. Has a clinically significant medical condition requiring treatment within 8 weeks before the initial study drug administration, or a history of clinically significant infection requiring treatment within 4 weeks before the initial drug administration.
2. History of surgical treatment such as resection of the liver, kidney, or Gastrointestinal tract, that may affect the Pharmacokinetic profiles of study drugs.
3. Ineligible for study participation in the opinion of the investigator or sub-investigator.