Study to Evaluate the Safety and Pharmacokinetics of Single Doses of ASP2151 in Healthy Male Subjects and the Effects of Food

Study will be divided into two parts. Part 1 will evaluate the safety and tolerability of ASP2151 single rising doses in groups A-H in fasted condition and to determine the maximum tolerable dose (MTD) if possible.

Part 2 will evaluate the effect of fasted versus fed conditions on the safety, tolerability and PK of a single dose of ASP2151 in two treatment cycles. The wash-out period between the two treatment cycles will be at least 5 days and not shorter than five times the average elimination half-life of ASP2151, as determined in part 1 of the study.

Inclusion criteria

• Body weight between 60 and 100 kg, and BMI between 18 and 30 kg/m2 inclusive

Exclusion criteria

• Known or suspected hypersensitivity to ASP2151 or any components of the formulation used
• Any clinically significant history of asthma, eczema, any other allergic condition or previous severe hypersensitivity to any drug
• Any clinically significant history of genital herpes symptoms and/or herpes zoster symptoms in the 3 months prior to admission to the Clinical Unit
• Any clinically significant history of any other disease or disorder - gastrointestinal, cardiovascular, respiratory, renal, hepatic, neurological, dermatological, psychiatric or metabolic
• Abnormal pulse rate and/or blood pressure measurements at the pre-study visit as follows: Pulse rate <40 or >90 bpm (beats per minute); mean systolic blood pressure <90 or >140 mmHg (millimeter of mercury); mean diastolic blood pressure <40 or >95 mmHg
• Regular use of any prescribed or OTC (over the counter) drugs in the 4 weeks prior to admission to the Clinical Unit OR any use of such drugs in the 2 weeks prior to admission to the Clinical Unit
• Any use of drugs of abuse within 3 months prior to admission to the Clinical Unit
• History of smoking more than 10 cigarettes per day within 3 months prior to admission to the Clinical Unit
• History of drinking more than 21 units of alcohol per week within 3 months prior to admission to the Clinical Unit
• Donation of blood or blood products within 3 months, prior to admission to the Clinical Unit
• Positive serology test for HBsAg (Hepatitis B surface antigen), HAV IgM (Hepatitis A Virus), anti-HCV (Hepatitis C Virus) or anti-HIV (Human Immunodeficiency Virus) 1 and 2
• Not willing or able to swallow size 00 capsules