Klatovy 1

Researchers are studying the safety and effectiveness of long-acting antibodies given alone or in combinations to adults with moderately to severely active ulcerative colitis (UC). This Phase 2, multicenter platform trial aims to find treatments that can improve symptoms and induce remission in people diagnosed with UC for at least 3 months. The study includes participants with active disease confirmed by endoscopy and histology and with moderate to severe symptoms based on a scoring system. The trial has two parts. Part A is an open-label phase testing three different monotherapy drugs to assess safety and initial effectiveness. Part B will be a randomized, placebo-controlled phase where participants receive one of six interventions (three monotherapies or three combinations) or placebo to compare outcomes. Treatments involve intravenous (IV) induction followed by subcutaneous (SC) maintenance dosing. Different treatment arms may start and finish at varying times during the study. Participants will undergo endoscopy and histology to confirm disease activity at screening, with regular monitoring throughout the study. Researchers will evaluate changes in disease severity using the Robarts Histopathology Index and measure the percentage of participants achieving clinical remission by Week 12. Safety and efficacy will be closely followed during and after treatment. The total study duration depends on treatment arm timelines and follow-up requirements.