This study is testing a drug called Povorcitinib to see if it is safe and works well for people with a skin condition called Hidradenitis Suppurativa (HS). HS causes painful lumps under the skin. The study will last 54 weeks in total, with the first 12 weeks comparing Povorcitinib to a placebo (a pill that looks the same but has no medicine). A placebo helps researchers see if the drug is really working. The next 42 weeks will continue to monitor the safety of Povorcitinib.

To join, you should have had moderate to severe HS for at least 3 months, with at least 5 painful lumps, and have tried other treatments that didn't work. You cannot have more than 20 draining tunnels (fistulas) in your skin. Pregnant women or those who want to become pregnant cannot participate. You must agree not to use certain antibiotics or antiseptic washes during the study.

• Study Length: 54 weeks (12 weeks placebo-controlled, 42 weeks extension)
• Participants must follow specific treatment rules.
• Pregnant or breastfeeding women cannot join.