Upon joining the study, participation begins with a randomized, double-blind, placebo-controlled maintenance phase. This phase is designed to evaluate the effectiveness and safety of risankizumab compared to a placebo.

Participants who have previously responded to intravenous risankizumab treatment in earlier studies are eligible for this phase.

During the study, risankizumab is administered in two forms: as a solution for infusion and as a solution for injection in a pre-filled syringe.

The intravenous form is used initially, followed by subcutaneous injections. The specific dosage and frequency are determined based on the study protocol.

The maintenance phase lasts for 52 weeks. Participants receive either risankizumab or a placebo during this period.

The goal is to assess the proportion of participants achieving clinical remission and endoscopic response by the end of the 52 weeks.

After completing the maintenance phase, participants may enter an open-label extension phase. This phase allows for continued treatment with risankizumab to evaluate long-term safety and effectiveness.

Participants who complete this phase may continue to receive treatment until it becomes commercially available or accessible locally.

Throughout the study, various assessments are conducted to monitor health status, including clinical remission, endoscopic response, and quality of life measures.

The study aims to ensure the safety and well-being of participants while gathering data on the long-term effects of risankizumab.