A Study to Evaluate the Efficacy and Safety of Subcutaneous Sonelokimab Compared with Placebo in Adult Participants with Moderate to Severe Hidradenitis Suppurativa

Inclusion Criteria:

1. Participants must be at least 18 years of age at the time of signing the informedconsent.

2. Participants who are diagnosed with hidradenitis suppurativa as determined by theinvestigator and have a history of signs and symptoms of hidradenitis suppurativafor at least 6 months before signing the informed consent.

3. Participants who have had an inadequate response to appropriate systemic antibioticsfor treatment of hidradenitis suppurativa (or demonstrated intolerance to, or had acontraindication to, systemic antibiotics for treatment of their HS), in theinvestigator's opinion.

4. Participants who have a total AN count of ≥5.

5. Participants who have HS lesions present in ≥2 distinct anatomical areas, at leastone of which must contain single or multiple fistulas (ie, be Hurley Stage II orIII).

Exclusion Criteria:

1. Participants with a known hypersensitivity to sonelokimab or any of its excipients.

2. Participants with any other active skin disease or condition that may, in theopinion of the investigator, interfere with the assessment of HS.

3. Participants with underlying conditions that, in the opinion of the investigator,potentially places the participant at unacceptable risk.

4. Participants with current severe or uncontrolled disease(s) that put(s) theparticipant at increased risk in the investigator's opinion, would preclude theparticipant from adhering to the protocol or completing the study per protocol.

5. Participants with any other known autoimmune disease or any medical condition thatin the opinion of the investigator would interfere with an accurate assessment ofclinical symptoms of HS.

6. Participants with a gastrointestinal condition including inflammatory bowel diseaseor diagnosis of ulcerative colitis or Crohn's disease.