A Study to Assess the Effects of Single Ascending Doses of ASP1707 in Healthy Young Japanese Male Subjects

A Double Blind, Randomized and Placebo Controlled Ascending Single Oral Dose, Safety, Tolerability, Pharmacokinetic and Pharmacodynamic Study of ASP1707 in Healthy Young Japanese Male Subjects

Three groups of 8 Japanese males are given single ascending doses of ASP1707 or placebo to assess the safety and tolerability, and to evaluate how it is absorbed, metabolized and distributed through the body.

The first group receives the lowest dose while the last group receives the highest dose. ASP1707 or matching placebo is administered as a single dose under fasted conditions.

Screening takes place from Day -22 to Day -2. Subjects are admitted to the clinic on Day -1 and remain until Day 5. An end of study visit (ESV) takes place 7-14 days after discharge.

Escalation to the next higher dose takes place after review of the safety and tolerability data from the previous dose.

Safety assessments are performed throughout the study. Plasma and urine samples are collected for pharmacokinetics (PK) analysis. Serum samples are collected for pharmacodynamic (PD) analysis.

Inclusion Criteria:

• Born in Japan
• Both parents are of Japanese descent
• Time residing outside Japan does not exceed 5 years
• Maintains Japanese life style including diet
• Male subject must be non-fertile, i.e. surgically sterilized or must practice an effective contraceptive method

Exclusion Criteria:

• Subjects with out-of-range T levels in serum at screening
• Subjects with any history of cancer