The study is a Phase 2, multi-center, randomized, double-blind, placebo-controlled study to evaluate the effects of tibulizumab over 16 weeks (Period 1) in adults with hidradenitis suppurativa, followed by a 16-week open-label extension period in which all participants will receive tibulizumab (Period 2)

Inclusion Criteria:

• Male or female, 18 to 70 years of age
• ≥6-month history of Hidradenitis suppurativa (HS)
• Total AN (abscess and inflammatory nodule) count ≥5
• HS lesions in ≥2 distinct anatomical areas, at least one of which is Hurley Stage II or III

Exclusion Criteria:

• Draining tunnel count >20
• Presence of another inflammatory condition or a skin condition that may interfere with study assessments
• Known to have immune deficiency or is immunocompromised
• Evidence or suspicion of active or latent tuberculosis
• History of opportunistic, chronic, or recurrent infection requiring chronic antibiotic use, serious or life-threatening infection within 2 months, or had an infection requiring systemic antibiotics within 2 weeks
• Has active systemic candidiasis
• Unable to tolerate subcutaneous drug administration