A Study to Evaluate the Efficacy and Safety of Povorcitinib (INCB054707) in Participants With Moderate to Severe Hidradenitis Suppurativa

Inclusion Criteria:

• Diagnosis of moderate to severe HS for at least 3 months prior to the screeningvisit.

• Total abscess and inflammatory nodule count of at least 5 at both the screening andbaseline visits

• HS lesions in at least 2 distinct anatomical areas (examples include but are notlimited to left and right axilla or left and right inguinocrural fold), 1 of whichmust be at least Hurley Stage II or Hurley Stage III, at both the screening andbaseline visits

• Documented history of inadequate response to at least a 3-month course of at least 1conventional systemic therapy (oral antibiotic or biologic drug) for HS (ordemonstrated intolerance to, or have a contraindication to, a conventional systemictherapy for treatment of their HS).

• Agreement to NOT use topical and systemic antibiotics for treatment of HS during theplacebo-controlled period.

• Agreement to NOT use a diluted bleach bath or topical antiseptic washes containingchlorhexidine gluconate or benzoyl peroxide on the areas affected by HS lesionsduring the placebo-controlled period. Note: Over-the-counter soap and water isallowed.

• Agreement to use contraception

• Willing and able to comply with the study protocol and procedures.

• Further inclusion criteria apply.

Exclusion Criteria:

• Presence of > 20 draining tunnels (fistulas) at either the screening or baselinevisit.

• Women who are pregnant (or who are considering pregnancy) or breastfeeding.

• Medical history including thrombocytopenia, coagulopathy or platelet dysfunction,Q-wave interval abnormalities, current or history of certain infections, cancer,lymphoproliferative disorders and other medical conditions at the discretion of theinvestigator.

• Laboratory values outside of the protocol-defined ranges.

• Further exclusion criteria apply.