Inclusion Criteria:

• able to give a written informed consent ;
• healthy male volunteers aged between 18 and 40 years;
• with body mass index (weight/height²) in the range 18 to 30 kg/m²;
• registered with the French Social Security in agreement with the French Law (Huriet Law : N° 88.1138 - 20.12.88) on biomedical experimentation;
• able to comply with protocol requirements, including blood and urine sample collections as defined in the protocol;
• not flu vaccination in the last two years.

Exclusion Criteria:

• who on direct questioning and physical examination have evidence of any clinically significant acute or chronic disease, including known or suspected HIV, HBV and HCV infection ;
• with any clinically significant abnormality following review of pre-study laboratory tests and full physical examination ;
• who have received any experimental drug within the exclusion period defined in the National Register for Healthy Volunteers of the French Ministry of Health ;
• who forfeit their freedom by administrative or legal award or who were under guardianship ;
• unwilling to give their informed consent ;
• who present a positive laboratory test for Hepatitis B surface antigen (HbsAg), HBc antibodies, HIV 1 and 2 antibodies and HCV antibodies ;
• who have a history of allergy or intolerance to the study drug ;
• who had a history of serious allergy, asthma, allergic skin rash or sensitivity to any drug ;
• who are known or suspected alcohol or drug abusers ;
• who present a positive laboratory test for urine drug screening (opiates, barbiturates, amphetamine, cannabis) ;
• who undergo surgery or have donated blood within 1 month prior to the start of the study ;
• who have taken any prescribed or over the counter drug (including antacid drug), with the exception of paracetamol (up to 3 g per day) within 1 week prior to the first dose administration ;
• who receive any drug known to affect hepatic metabolism like cimetidine, ketoconazole, fluconazole, itraconazole, phenytoin, rifampicin, rifabutin within 1 month prior to the first dose administration ;
• who receive any drug known to affect renal tubular secretion like probenecid, beta-lactam antibiotics within 2 weeks prior to the first dose administration ;
• who present any clinical condition or prior therapy which, in the opinion of the investigator, made the subject unsuitable for the study.