Comparison of the Relative Oral Bioavailability of GKT137831 Formulated in Capsules or in Tablets

Inclusion Criteria: 1. Healthy male subject, aged 18 to 60 years inclusive; 2. Non-smoker subject or smoker of not more than 5 cigarettes a day ; 3. No history of alcohol or drug abuse 4. Body Mass Index (BMI) between 18 and 27 5 kg/m2 inclusive; 5. Considered as healthy after a comprehensive clinical assessment (detailed medical history and complete physical examination); 6. Signing a written informed consent prior to selection; Exclusion Criteria: 1. Blood donation (including in the frame of a clinical study) within 2 months before administration; 2. General anaesthesia within 3 months before administration; 3. Presence or history of drug hypersensitivity, or allergic disease diagnosed and treated by a physician; 4. Inability to abstain from intensive muscular effort; 5. No possibility of contact in case of emergency; 6. Any drug intake (except paracetamol) during the last month prior to the first administration; 7. History or presence of drug or alcohol abuse (alcohol consumption \> 40 grams / day); 8. Excessive consumption of beverages with xanthine bases (\> 4 cups or glasses / day); 9. Positive Hepatitis B surface (HBs) antigen or anti Hepatitis C Virus (HCV) antibody, or positive results for Human Immunodeficiency Virus (HIV) 1 or 2 tests; 10. Positive results of screening for drugs of abuse; 11. Subject who, in the judgment of the Investigator, is likely to be non-compliant or uncooperative during the study, or unable to cooperate because of a language problem, poor mental development; 12. Exclusion period of a previous study; 13. Administrative or legal supervision;