
The Interleukin 23 (IL-23) cytokine is a heterodimeric cytokine consisting of the two subunits p19 and p40. It is an inducer of the Th17 cell population and a component of the IL-23/IL-17 immune pathway which is an orchestrator of many pathological conditions, including psoriasis.
Due to its crucial role in pathogenesis, the two IL-23 subunits are promising therapeutic targets for inflammatory conditions. The first approved biologic agent targeting IL-23 was ustekinumab (Stelara), a fully human monoclonal antibody against the shared IL-12/IL23 p40 subunit that was approved for the indication of psoriasis and Chron’s disease. Guselkumab (Tremfya), a monoclonal antibody targeting the IL23p19 subunit was recently approved for the treatment of psoriasis, while tildrakizumab (Ilumya), also targeting IL23p19, and other therapeutics are currently under development.