This study is testing a new drug called tulisokibart for people with hidradenitis suppurativa (HS), a skin condition that causes painful lumps. The study aims to see if tulisokibart works better than a placebo, which is a "fake" treatment with no active drug, by checking if it reduces the condition by half after 16 weeks. The study has two parts: a 16-week period where neither the doctor nor the patient knows if they're getting the real drug or placebo, called double-blind, and a longer extension that can go up to 100 weeks.

• The first part lasts 16 weeks, and the longer part is optional and can last up to 100 weeks.
• Participants must have moderate or severe HS and have tried antibiotics without success.
• People with certain other skin or immune issues, or those allergic to the study drug, cannot join.