The drug, a fully human monoclonal antibody that selectively binds to IL-1 receptor 1 (IL-1R1) and inhibits its activation by both IL-1α and IL-1β, was evaluated in a phase II trial to provide preliminary evidence of the safety, tolerability, and efficacy of MEDI8968 in subjects with moderate to severe HS, as assessed by the proportion of subjects achieving PGA 0, 1, or 2 at week 12 (NCT01838499). This evidence concerns the gene IL1R1 and histiocytic sarcoma.