A Phase I Study to Compare 3 Different Strengths of an Extended Release Formulation of ASP015K to an Immediate Release Formulation of ASP015K

Exclusion Criteria

• •The subject has a previous history of any clinically significant gastro-intestinal, neurological, renal, hepatic, pulmonary, metabolic, cardio-vascular, psychiatric, endocrine, hematological disorder or disease, malignancy excluding non-melanoma skin cancer or any other medical condition that, in the Investigator's opinion, would preclude participation in the study
• •The subject has had major GI surgery (such as colectomy, cholecystectomy, etc) which may inhibit the absorption and/or metabolism of study drug
• •The subject has a history of consuming more than 14 units of alcoholic beverages per week or has a history of alcoholism or drug/chemical/ substance abuse within past 2 years prior to Screening (Note: one unit = 12 ounces of beer, 4 ounces of wine or 1 ounce of spirits)
• •The subject has a positive test for alcohol or drugs of abuse at Screening or Day -1
• •The subject has a positive cotinine test at Screening or Day -1
• •The subject has had treatment with prescription, non-prescription or complementary and alternative medicines (CAM) within 14 days prior to Day -1 (of initial treatment period) with the exception of stable hormone replacement therapy (HRT) and/or occasional use of acetaminophen (up to a maximum of 2 g/day)
• •The subject has/had a symptomatic, viral, bacterial (including upper respiratory infection), or fungal (non-cutaneous) infection within 1 week prior to Day -1
• •The subject has a positive test for hepatitis C antibody, or positive test for hepatitis B surface antigen (HBsAg), or positive hepatitis B core antibody at Screening
• •The subject has a history of the human immunodeficiency virus (HIV) antibody
• •The subject has a positive tuberculosis (TB) skin test, Quantiferon Gold test or T-SPOT® test at Screening
• •The subject received any vaccine within 60 days prior to study drug administration
• •The subject has received an experimental agent within 30 days or five half-lives, whichever is longer, prior to study drug administration
• •The subject has had any significant blood loss, donated one unit (450 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 clinic admission on Day -1
• •The subject has an absolute neutrophil count (ANC) \< 2500 cells/mm3 or a CPK \> 1.5x upper limit of normal at Screening and Day -1 of initial treatment period
• •The subject has smoked or has used tobacco-containing products and nicotine or nicotine-containing products in the past six months prior to Screening