Unknown Manufacturer • Ustekinumab is indicated for the management of moderate to severe plaque psoriasis in patients 6 years of age and older who are candidates for phototherapy or systemic therapy. In adult patients, it is also indicated for the management of active psoriatic arthritis (PsA) alone or in combination with methotrexate, moderately to severely active Crohn’s disease (CD) and moderately to severely active ulcerative colitis.
Ustekinumab is a targeted antibody therapy used to manage inflammatory conditions such as plaque psoriasis, psoriatic arthritis, Crohn's Disease, and ulcerative colitis.
Interleukin (IL)-12 and IL-23 are heterodimeric cytokines that evoke immune and inflammatory responses, such as natural killer cell activation and CD4+ T-cell differentiation and activation. The role of IL-12 and IL-23 were implicated in a variety of chronic inflammatory conditions, such as psoriasis and inflammatory bowel diseases. They modulate lymphocyte function, including T-helper (Th) 1 and Th17 cell subsets, as CD4+ T cells can differentiate into T-helper (Th) effector lineages based on the environment. Th cells can further activate the downstream pro-inflammatory mediators and transcription factors such as TNFα and IFNγ that drive innate and adaptive immunity. IL-12 and IL-23 share a common p40 subunit, paired with p35 and p19 subunits of IL-12 and IL-23, respectively. The antigen-binding fragment (Fab) of ustekinumab binds the D1 domain of the p40 subunit of IL-12 and IL-23 in a 1:1 ratio. This prevents IL-12 and IL-23 from binding to the IL-12Rβ1 receptor chain of IL-12 (IL-12Rβ1/β2) and IL-23 (IL-12Rβ1/23R) receptor complexes on the surface of NK and T cells. Ustekinumab only binds to IL-12 and IL-23 that are unbound to IL-12Rβ1, so it is unlikely to initiate Fc effector functions, such as ADCC or CDC. Inhibition of the IL-12/23 signalling pathway leads to profound suppression of both the Th1 and Th17 cell lineage of cytokines and chemokines and their inflammatory pathways.
