Screening takes place between Day -22 to Day -2. Subjects are admitted to the clinical on Day -1 and remain until Day 12.~On Days 5 to 9, subjects receive twice-daily doses of ASP3652, and a single dose on the morning of Day 10. Subjects fast for 10h before the morning dose on Days 5 to 9 and they are served the first standard meal 1h after the morning dose.~A spinal tap is used to collect cerebrospinal fluid (CSF) on Day 1 and Day 10. A plasma sample for PK sample is obtained before first dosing on Day 5. To confirm steady-state concentrations of ASP3652 in plasma, blood samples are obtained before the morning dose on Days 7, 9 and 10, and before the evening dose on Days 5, 7 and 9. On Day 10, a PK profile of ASP3652 in plasma is obtained for up to 48h after the morning dose and for up to 24h in CSF.~Profiles of several enzyme substrates in plasma and seminal fluid (exploratory) are obtained on Day 1 and Day 10 up to 24h in CSF and up to 48h in plasma, before the morning and evening dose on Days 5, 7 and 9 in plasma.~Vital signs, 12-lead electrocardiograms (ECGs), safety laboratory assessments, adverse events (AEs) and concomitant medication are monitored throughout the investigational period until the ESV.
The purpose of this study is to evaluate the plasma and cerebrospinal fluid (CSF) pharmacokinetics (PK) of multiple doses of ASP3652 in healthy young Caucasian male subjects. Also to evaluate the plasma and CSF pharmacodynamics (PD) of multiple doses of ASP3652 in healthy young Caucasian male subjects and to assess the safety and tolerability of multiple doses of ASP3652 in healthy young Caucasian male subjects.