Lunsayil 1: A Study to Test Whether Spesolimab Helps People With a Skin Disease Called Hidradenitis Suppurativa

This study is open to adults with moderate to severe hidradenitis suppurativa (HS). The purpose of this study is to find out whether a medicine called spesolimab helps people with HS. People who have previously taken specific medicines such as immunosuppressive biologics other than Tumor necrosis factor (TNF) inhibitors cannot take part. This study has 2 parts. In Part 1, participants are divided into 4 groups of almost equal size. 3 groups get different doses of spesolimab, 1 group gets placebo. All participants get injections into a vein or under the skin. Placebo injections look like spesolimab injections, but do not contain any medicine. Every participant has an equal chance of being in each group. In the beginning, participants get the study medicine every week and later every 2 weeks. After 4 months, participants in the placebo group switch to spesolimab treatment. In Part 2, participants are divided into 2 groups. One group gets a suitable dose of spesolimab that was found in Part 1 of the study. The other group gets placebo. After 4 months, participants in the placebo group switch to spesolimab treatment. Participants join only one of the two parts. They are in the study for about 1 year. During this time, they visit the study site in the beginning every week and later every 2 weeks. Some of the visits can be done at the participant's home instead of the study site. The doctors regularly check participants' HS symptoms. The results are compared between the groups to see whether spesolimab works. The doctors also regularly check participants' general health and take note of any unwanted effects.

Main endpoints for Part 2 will be supported by Part 1 results available at time of primary analysis.