This Study Tests How BI 655130 Works in Patients With Active Ulcerative Colitis. The Study Also Tests How Well BI 655130 is Tolerated and Whether it Helps the Patients

Exploratory Trial to Assess Mechanism of Action, Clinical Effect, Safety and Tolerability of 12 Weeks of Treatment With BI 655130 in Patients With Active Ulcerative Colitis (UC)

The primary objective of this trial is to understand the mechanism of action of BI655130 in patients with UC

Secondary objectives are to explore clinical effect, safety and tolerability (including immunogenicity) of BI 655130 treatment

Inclusion Criteria:

• 18 - 75 years at screening
• Diagnosis of UC >= 3 months prior to screening.
• Moderately to severely active UC as confirmed by Mayo Score ≥6
• Receiving conventional, non-biologic therapy for UC.
• Negative colon cancer screening
• Further inclusion criteria apply

Exclusion Criteria:

• Prior use of any biological treatment in the past (e.g.integrin inhibitors, IL12/23 or IL23 inhibitors, any investigational biological drugs)
• Extensive colonic resection
• Evidence of infection with C. difficile or other intestinal pathogen < 30 days prior to screening
• Active or latent tuberculosis
• Further exclusion criteria apply