Aged ≥ 12 to \< 18 years at the time of informed consent/assent signing.
Body weight ≥ 30 kg at both screening and baseline visits.
Diagnosis of moderate to severe HS for at least 3 months prior to the screening visit.
Total abscess and inflammatory nodule count of at least 5 at both the screening and baseline visits.
HS lesions corresponding to refined Hurley Stage IB, IC, IIB, IIC, or III at both the screening and baseline visits.
Documented history of inadequate response to at least a 3-month course of at least 1 conventional systemic therapy (oral antibiotic or biologic drug) for HS (or demonstrated intolerance to, or have a contraindication to, a conventional systemic therapy for treatment of their HS).
Agreement to use contraception.
Willing and able to comply with the study protocol and procedures.
You may not be if
Presence of \> 20 draining tunnels (fistulas) at either the screening or baseline visit.
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 the investigator.
Laboratory values outside of the protocol-defined ranges.
