The purpose of this study is to test the long-term safety and tolerability of SPD476 in the maintenance of ulcerative colitis remission.

Inclusion Criteria:

• Subjects must have completed all assessments of SPD476-301 or SPD476-302 End of Study/Early Withdrawal Visit
• Subjects who did not achieve remission at the End of Study/Early Withdrawal Visits in Study 301 or 302 will be eligible to enter the Acute Phase; subjects who did achieve remission at the End of Study Visits in Study 301 or 302 will be eligible to enter directly into the Maintenance Phase
• Women of childbearing potential must use an acceptable contraceptive method while on study treatment

Exclusion Criteria:

• Subjects who withdrew from Study 301 or 302 before Study Visit 3, or who withdrew due to a possible or probably related severe adverse event or serious adverse event are not eligible to enter this study