The FDA has approved the interleukin (IL)-23 blocker guselkumab (Tremfya – Janssen) for treatment of moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy. Guselkumab is the first selective IL-23 blocker to become available in the US.
IL-23 is a cytokine involved in normal inflammatory and immune responses. Guselkumab is a fully human monoclonal IgG1 antibody that selectively binds to the p19 subunit of IL-23, inhibiting it from binding to the IL-23 receptor and preventing downstream release of pro-inflammatory cytokines (such as IL-17A) and chemokines (Table 1 and Table 2).