• Proportion of subjects achieving clinical remission at defined time points [ Time Frame: Week 8 and Week 52 ] [ Designated as safety issue: No ]
  

• Patient reported outcomes [ Time Frame: Week 8, Week 32 and Week 52 ] [ Designated as safety issue: No ]
  
• Clinical response indicators [ Time Frame: Week 8, Week 32 and Week 52 ] [ Designated as safety issue: No ]
  
• Safety parameters [ Time Frame: Week 8, Week 32 and Week 52 ] [ Designated as safety issue: Yes ]
  

Inclusion Criteria:

• Subjects >=18 years of age and in good health (Investigator discretion) with a recent stable medical history
• Diagnosis of ulcerative colitis for greater than 90 days prior to Baseline
• Diagnosis of active ulcerative colitis confirmed by colonoscopy with biopsy or flexible sigmoidoscopy with biopsy during the Screening Period, with exclusion of infection

• Active ulcerative colitis that is poorly controlled despite concurrent treatment with oral corticosteroids and/or immunosuppressants as defined below:

  • Stable (± 5 mg) corticosteroid dose (prednisone >= 20 mg/day or equivalent) for at least 14 days prior to Baseline or maintenance, corticosteroid dose (prednisone < 20 mg/day or equivalent) for at least 40 days prior to Baseline
  • At least a 90 day course of azathioprine or 6-MP prior to Baseline, with a dose of azathioprine >= 1.5 mg/kg/day or 6-MP >= 1 mg/kg/day (rounded to the nearest available tablet formulation), or a dose that is the highest tolerated by the subject (e.g., due to leukopenia, elevated liver enzymes, nausea) during that time. Subject must be on a stable dose for at least 28 days prior to Baseline
• Concurrent therapy will not be required for subjects who were previously treated with corticosteroids or immunosuppressants (azathioprine or 6-MP) during the past 5 years and in the judgment of the investigator have failed to respond to or could not tolerate their treatment.
• Subjects may be included if they have previously used an anti-TNF agent (except adalimumab) and discontinued its use due to a loss of response or intolerance to the agent
• Subject is judged to be in generally good health as determined by the principal investigator

Exclusion Criteria:

• History of subtotal colectomy with ileorectostomy or colectomy with ileoanal pouch, Koch pouch, or ileostomy for ulcerative colitis or is planning bowel surgery
• Received previous treatment with adalimumab or previous participation in an adalimumab clinical study
• Current diagnosis of fulminant colitis and/or toxic megacolon
• Subject with disease limited to the rectum (ulcerative proctitis)
• Current diagnosis of indeterminate colitis
• Current diagnosis and/or history of Crohn's disease
• Currently receiving total parenteral nutrition (TPN)
• Subject using aminosalicylates for less than 90 days prior to Baseline or not on a stable dose for at least 28 days prior to Baseline or discontinued use within 28 days of Baseline
• Subject who has previously used infliximab or any anti-TNF agent within 56 days of Baseline
• Subject who has previously used infliximab or any anti-TNF agent and has not clinically responded at any time ("primary non-responder") unless subject experienced a treatment limiting reaction
• Female subject who is pregnant or breast-feeding or considering becoming pregnant during the study
• Subject with any prior exposure to Tysabri® (natalizumab)
• Subject considered by the investigator, for any reason, to be an unsuitable candidate
• Subject currently taking both budesonide and prednisone (or equivalent) simultaneously