Study to Evaluate the Safety and Pharmacokinetics of ASP2151 in Healthy Non-elderly and Elderly Subjects

Inclusion Criteria: * Body weight: ≥50.0 kg and \<85.0 kg * Body mass index (BMI): ≥17.6 and \<26.4 kg/m2 Exclusion Criteria: * Subjects with a complication of any diseases * Subjects with a history of hepatic disease * Subjects with a history of heart disease * Subjects with a history of respiratory disease * Subjects with a history of alimentary disease * Subjects with a history of renal disease * Subjects with a history of cerebrovascular disorder * Subjects with a history of malignant tumor * Subjects with a history of drug allergies or allergies disorders excluding pollinosis * Subjects with a history of drug dependency or alcohol dependence syndrome * Subjects who developed genital herpes or herpes zoster within 90 days before the initial dosing * Subjects who do not meet any of the criteria for laboratory tests * Subjects who received medications within 14 days before the initial dosing. * Subjects who received any investigational drugs in other clinical trials or post-marketing studies within 120 days before screening or the initial dosing * Excessive alcohol drinking or smoking habit * Subjects who previously received administration of ASP2151 (including placebo) * Abnormalities detected on an ophthalmological examination * Subjects who deviate from the normal range of standard 12-lead ECG at screening