The purpose of this study is to determine the pharmacokinetics (PK) and to assess safety and tolerability of a single dose of ASP3291 in subjects with ulcerative colitis.

After an 11-day screening period, subjects check into a clinic, are dosed on Day 1 and stay in the clinic for 4 days to monitor pharmacokinetic and safety parameters.

Inclusion Criteria:

• Subject has a previously documented diagnosis of ulcerative colitis (UC) with endoscopy and histology consistent with diagnosis
• If female, the subject is at least 2 years postmenopausal or is surgically sterile per documentation provided by a third party medical professional or the subject agrees to use 2 highly effective methods of birth control during the study and is not pregnant or lactating
• Subject is willing and able to comply with the study requirements
• Subject has a body mass index (BMI) of <32 kg/m2
• Subject has ulcerative colitis requiring treatment with 5-aminosalicylic acid (5-ASA)

Exclusion Criteria:

• Subject has undergone previous resective colonic surgery
• Subject has previously diagnosed Crohn's Disease based on medical history
• Subject has an extension of disease limited to ulcerative proctitis
• Subject has active peptic ulcer disease based on medical history
• Subject is currently being treated with any prescription medication except the following: A stable dose of 5-aminosalicylic acid (5-ASA) for at least 2 weeks, oral contraceptives or hormone replacement therapy (HRT)
• Subject has a history of human immunodeficiency virus (HIV)
• Subject has a history of severe allergic or anaphylactic reactions
• Subject has a history of drug or alcohol abuse