New Biologic and Small Molecule Therapies for Hidradenitis Suppurativa

ABSTRACT Hidradenitis suppurativa (HS) is an inflammatory skin disease that has historically been underdiagnosed and, until recently, under‐researched. Furthermore, the pathophysiology of HS is complex, and not fully understood. Just three biologic medications—adalimumab (anti‐TNF‐α), secukinumab (anti‐IL17A) and bimekizumab (anti‐IL17A/F) are licensed for the treatment of HS. Other biologics and small molecules have been used off‐licence for the treatment of HS, and evidence for their efficacy comes from case series and small clinical trials. The treatment landscape for HS is expanding, and new biologics and small molecules have been investigated in Phase 2 clinical trials. Those with clinically significant effects on disease activity have progressed to, or are planned to progress to, Phase 3 trials. This review discusses those medications under investigation currently, and the current licenced and off licence treatments available in clinical practice. It highlights some of the difficulties that arise in HS research, and their potential impact on the study and licencing of medications for HS.