BFB759 loading dose followed by BFB759 maintenance high dose every 2 weeks (Q2W) through Week 14 (inclusive), which is followed by placebo Q2W at Weeks 16 through 30 (inclusive).

BFB759 loading dose followed by BFB759 maintenance mid-dose Q2W through Week 14 (inclusive).

Placebo Q2W for 14 weeks. At Week 16, participants in Placebo group who are still enrolled in the study and receiving treatment will be re-randomized (1:1) into 2 groups (Cross 1 and Cross 2) to receive BFB759

• Cross 1 will receive BFB759 loading dose followed by BFB759 maintenance low-dose Q2W through Week 30 (inclusive).
• Cross 2 will receive BFB759 loading dose followed by BFB759 maintenance mid-dose Q2W through Week 30 (inclusive).

BFB759 is a human mAb that inhibits multiple pro-inflammatory cytokines that contribute to the pathogenesis of multiple disease processes characterized by aberrant inflammation, including hidradenitis suppurativa.

To evaluate the efficacy of BFB759 in adult male and female participants with HS as measured by the change in the number of abscesses and inflammatory nodules (AN count).

The HiSCR50 is defined as at least a 50% reduction in inflammatory lesion count [the sum of Abscesses and Inflammatory Nodules (AN)] and no increase in abscess count and no increase in draining fistula count relative to baseline. The threshold of 50% reduction in AN count is the defined level that is clinically appropriate and meaningful to the patient regarding improvement in quality of life and pain level.