A Study to Learn How [14C]ASP0367 is Processed by the Body in Healthy Men

ASP0367 is a potential new treatment for people with Duchenne Muscular Dystrophy and Mitochondrial Myopathies. Before ASP0367 is available as a treatment, the researchers need to understand how it is processed by and acts upon the body. This study is in healthy men. The main aim of this study is to learn how ASP0367 is processed by and acts upon the bodies of healthy men. To do this, \[14C\] which is a certain chemical (called a tracer, or radionuclide) has been added to ASP0367. \[14C\] gives off radiation, but the dose is very low (about the same as the dose from an x-ray) and will leave the body within a few days. \[14C\] will be picked up by a scanner and will be used to follow ASP0367 through the body. \[14C\]ASP0367 will be a liquid. During the study, the men who take part will stay in the clinic for 6 days and 5 nights. Some men may need to stay up to an extra 7 days in the clinic. This will happen if there is a medical reason or if they still have traces of radiation in their blood, urine or feces. On the day before they drink \[14C\]ASP0367, the men will be asked about their medical history, have a medical examination, and have their vital signs checked (blood pressure and pulse). They will also have an ECG to check their heart rhythm. They will give urine, stool and blood samples for laboratory tests. They will also be asked if they have had any medical problems. The men will fast for 10 hours or more before drinking \[14C\]ASP0367 and for 4 hours afterwards. They will only have one drink of \[14C\]ASP0367. They will need to lie still for 4 hours after drinking \[14C\]ASP0367. They will have their vital signs checked and give urine, stool and blood samples for laboratory tests. Then, they will give urine, stool and blood samples every day until they leave the clinic. They will also be asked every day if they have had any medical problems. The day after they drink \[14C\]ASP0367, the men will also have an ECG. On the last clinic day, the men will also h