Eligibility Criteria:
Inclusion Criteria:
* Subject is a healthy young male or female subject aged 25 to 55 years, inclusive, at screening (part 1 and 2) or healthy elderly female subject aged ≥ 65 years, inclusive, at screening (part 2 only).
* Subject has a body mass index (BMI) range of 18.5 - 30.0 kg/m2, inclusive. The subject weighs at least 50 kg (at screening).
* Subject agrees not to participate in another interventional study while participating in the present study, defined as signing the informed consent form until completion of the last study visit.
Exclusion Criteria:
* Female subject who has been pregnant within 6 months prior to screening assessment or breastfeeding within 3 months prior to screening.
* Subject has a known or suspected hypersensitivity to ASP2205 or any components of the formulations used.
* Subject has any of the liver function tests (LTs; aspartate aminotransferase \[AST\], alanine aminotransferase \[ALT\], alkaline phosphatase (ALP), gamma glutamyl transferase, total bilirubin \[TBL\]) above the upper limit of normal (ULN). In such a case, the assessment may be repeated once (admission to the clinical unit).
* Subject has at screening any clinically significant history of allergic conditions (including drug allergies, asthma, eczema or anaphylactic reactions, but excluding untreated, asymptomatic, seasonal allergies).
* Subject has any history or evidence of any clinically significant cardiovascular, gastrointestinal, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic (including surgical procedures to treat pelvic trauma), pulmonary, neurologic, dermatologic, psychiatric, renal and/or other major disease or malignancy.
* Subject has/had febrile illness or symptomatic, viral, bacterial (including upper respiratory infection), or fungal (noncutaneous) infection within 1 week prior to admission to the clinical unit.
* Subject has a relevant history of attempted suicide or suicidal behavior. Any recent suicidal ideation within the last 6 months or who are at significant risk to commit suicide.
* Subject has any clinically significant abnormality.
* Subject has a mean pulse \< 40 or \> 90 bpm; mean systolic blood pressure (SBP) \> 140 mmHg; mean DBP \> 90 mmHg (elderly subjects: mean SBP \> 160 mmHg; mean DBP \> 100 mmHg) (vital signs measurements taken in triplicate after subject has been resting in supine position for 5 minutes; pulse will be measured automatically) prior to the admission to the clinical unit (triplicates taken at screening and on admission to the clinical unit). If the mean blood pressure exceeds the limits above, 1 additional triplicate can be taken.
* Subject has a mean corrected QT interval using Fridericia's formula (QTcF) \> 430 ms (for male subjects) and \> 450 ms (for female subjects) at admission to the clinical unit. If the mean QTcF exceeds the limits above, 1 additional triplicate ECG can be taken.
* Subject uses any prescribed or nonprescribed drugs (including vitamins, natural and herbal remedies, e.g., St. John's Wort) in the 2 weeks prior to study drug administration, except for occasional use of paracetamol (up to 2 g/day) and except for use of contraceptives or hormone replacement therapy.
* Subject has a history of smoking within 6 months prior to admission to the clinical unit.
* Subject has a history of drinking \> 21 units of alcohol per week (1 unit = 10 g pure alcohol = 250 mL of beer \[5%\] or 35 mL of spirits \[35%\] or 100 mL of wine \[12%\]) (\> 14 units of alcohol for female subjects) within 3 months prior to admission to the clinical unit.
* Subject uses grapefruit juice (more than 3 × 200 mL) or products containing grapefruit and/or Seville oranges (more than 3 times) in the week prior to admission to the clinical unit until ESV, as reported by the subject.
* Subject uses any drugs of abuse within 3 months prior to admission to the clinical unit.
* Subject regularly uses any inducer of metabolism (e.g., barbiturates, rifampin) in the 3 months prior to admission to the clinical unit.
* Subject had significant blood loss, donated 1 unit (500 mL) of blood or more, or received a transfusion of any blood or blood products within 60 days or donated plasma within 7 days prior to admission to the clinical unit.
* Subject has a positive serology test for hepatitis B surface antigen (HBsAg), hepatitis A virus antibodies (immunoglobulin M) (anti-HAV \[IgM\]), hepatitis C virus antibodies (anti-HCV) or antibodies to human immunodeficiency virus type 1 (HIV-1) and/or type 2 (HIV-2) at screening.
* Subject has been treated with any investigational drugs within 90 days or 5 terminal half-lives, whichever is longer, prior to drug administration.
* Subject is unable to communicate, read and understand English, or has any other condition which makes the subject unsuitable for study participation.
* Subject is an employee of the Astellas Group or Clinical Research Organization involved in the study.