A Study to Find a Suitable Dose of ASP8731 and Check for Medical Problems at Each Dose in Healthy Adults

Study Summary

ASP8731 is a potential new treatment for people with sickle cell disease. Before ASP8731 is available as a treatment, the researchers need to understand how it is processed by and acts upon the body. They do this to find a suitable dose and to check for potential medical problems from the treatment. This type of study usually includes healthy adults but can include people with the relevant condition. The main aim of this study is to learn if healthy adults have any medical problems after taking different doses of ASP8731. This study will be in 2 parts. In Part 1, different small groups of people will take lower to higher doses of ASP8731 or a placebo. In this study a placebo looks like ASP8731 but will not have any medicine in it. This is done to find suitable doses of ASP8731 and work out how often it should be taken. Some of this information will be used in Part 2 of the study. The first group will take the lowest dose of ASP8731 or the placebo. A medical expert panel will check the results from this group and decide which ASP8731 dose the next group can take. The panel will do this for each group until all groups have taken ASP8731 or until a suitable dose of ASP8731 has been reached. In Part 1, people will visit the study clinic 4 times. The first visit is to check if they can take part. People will be asked about their medical history, have a physical exam, and their vital signs checked (pulse rate, temperature, and blood pressure). Also, they will have an ECG to check their heart rhythm and have some blood samples taken for laboratory tests. For women this will include a pregnancy test. At the second visit, people will stay in the study clinic for a few days. In most groups, people will be picked to take either ASP8731 or the placebo by chance alone. They will fast before taking ASP8731 or the placebo. 1 group will take ASP8731 with food. No-one in that group will take the placebo. After taking ASP8731 or the placebo (or just ASP8731 with food), people in

Primary Outcome

Adverse Events (AEs) will be coded using medical dictionary for regulatory activities (MedDRA). An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study IP, whether or not considered related to the study investigational product (IP). An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study IP. Th

Interventions

• DRUG ASP8731
• DRUG ASP8731 Matching Placebo