Eligibility Details:  
        Inclusion Criteria:
          -  For cohorts that enroll non-Asian subjects, subject does not have East Asian (China,
             Hong Kong, Macau, Japan, Mongolia, North Korea, South Korea and Taiwan) ancestries.
          -  For cohorts that enroll Japanese subjects, subject is first generation Japanese, born
             in Japan with 4 grandparents of Japanese descent, and must have resided outside of
             Japan for ≤ 10 years.
          -  Subject has a body mass index (BMI) range of 18.5 to 32.0 kg/m2, inclusive and weighs
             at least 50 kg at screening.
          -  Female subject is not pregnant and at least 1 of the following conditions apply:
               -  Not a woman of childbearing potential (WOCBP)
               -  WOCBP who agrees to follow the contraceptive guidance from the time of informed
                  consent through at least 30 days after final investigational product (IP)
                  administration.
          -  Female subject must agree not to breastfeed starting at screening and throughout the
             study period and for 30 days after final IP administration.
          -  Female subject must not donate ova starting at first dose of IP and throughout the
             study period and for 30 days after final IP administration.
          -  Male subject with female partner(s) of child-bearing potential (including
             breastfeeding partner[s]) must agree to use contraception throughout the treatment
             period and for 30 days after final IP administration.
          -  Male subject must not donate sperm during the treatment period and for 30 days after
             final IP administration.
          -  Male subject with pregnant partner(s) must agree to remain abstinent or use a condom
             for the duration of the pregnancy throughout the study period and for 30 days after
             final IP administration.
          -  Subject agrees not to participate in another interventional study while participating
             in the present study.
        Exclusion Criteria:
          -  Subject has received any investigational therapy within 28 days or 5 half-lives,
             whichever is longer, prior to screening.
          -  Subject has any condition, which makes the subject unsuitable for study participation.
          -  Female subject who has been pregnant within 6 months prior to screening or
             breastfeeding within 3 months prior to screening.
          -  Subject has a known or suspected hypersensitivity to ASP1617 or any components of the
             formulation used.
          -  Subject has had previous exposure with ASP1617.
          -  Subject has any of the liver function tests (alkaline phosphatase [ALP], ALT, AST,
             gamma glutamyl transferase and TBL) above the upper linit of normal (ULN) on day -1.
             In such a case, the assessment may be repeated once.
          -  Subject has creatinine level outside normal limits on day -1. In such a case, the
             assessment may be repeated once.
          -  Subject has any clinically significant history of allergic conditions (including drug
             allergies, asthma, eczema or anaphylactic reactions, but excluding untreated,
             asymptomatic, seasonal allergies) prior to first IP administration.
          -  Subject has any history or evidence of any clinically significant cardiovascular,
             gastrointestinal, endocrinologic, hematologic, hepatic, immunologic, metabolic,
             urologic, pulmonary, neurologic, dermatologic, psychiatric, renal and/or other major
             disease or malignancy.
          -  Subject has/had febrile illness or symptomatic, viral, bacterial or fungal infection
             within 1 week prior to day -1.
          -  Subject has any clinically significant abnormality following the physical examination,
             ECG and protocol-defined clinical laboratory tests at screening or on day -1.
          -  Subject has a mean pulse < 45 or > 90 bpm; mean systolic blood pressure (SBP)140 mmHg;
             mean diastolic blood pressure (DBP) > 90 mmHg (measurements taken in triplicate after
             subject has been resting in the supine position for at least 5 minutes; pulse will be
             measured automatically) on day -1. If the mean blood pressure exceeds the limits
             above, 1 additional triplicate may be taken.
          -  Subject has a mean QTcF of > 430 msec (for male subjects) and > 450 msec (for female
             subjects) on day -1. If the mean QTcF exceeds the limits above, 1 additional
             triplicate ECG may be taken.
          -  Subject has used any prescribed or nonprescribed drugs in the 2 weeks prior to first
             IP administration, except for occasional use of acetaminophen (up to 2 g/day) topical
             dermatological products, including corticosteroid products, hormonal contraceptives or
             hormone replacement therapy (HRT).
          -  Subject has smoked, used tobacco-containing products and nicotine or
             nicotine-containing products (e.g., electronic vapes) within 6 months prior to
             screening.
          -  Subject has a history of consuming > 14 units for male subjects or > 7 units for
             female subjects of alcoholic beverages per week within 6 months prior to screening or
             has a history of alcoholism or drug/chemical/substance abuse within 2 years prior to
             screening or the subject tests positive for alcohol at screening or on day -1.
          -  Subject has used any drugs of abuse within 3 months prior to day -1 or the subject
             tests positive for drugs of abuse at screening or on day -1.
          -  Subject has used any inducer of metabolism in the 3 months prior to day -1.
          -  Subject has had significant blood loss, donated ≥ 1 unit (450 mL) of whole blood or
             donated plasma within 7 days prior to day -1 and/or received a transfusion of any
             blood or blood products within 60 days.
          -  Subject has a positive serology test for hepatitis A virus (HAV) antibodies, hepatitis
             B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies or antibodies to human
             immunodeficiency virus (HIV) type 1 and/or type 2 at screening.
          -  Subject is an employee of Astellas, the study-related contract research organizations
             (CROs) or the clinical unit.