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ustekinumab
Modality
mAb
Mechanism
12.1 Mechanism of Action Ustekinumab products are human IgG1қ monoclonal antibodies that binds with specificity to the p40 protein subunit used by both the IL-12 and IL-23 cytokines. IL-12 and IL-23 are naturally occurring cytokines that are involved in inflammatory and immune responses, such as natural killer cell activation and CD4+ T-cell differentiation and activation. In in vitro models, ustekinumab products were shown to disrupt IL-12 and IL-23 mediated signaling and cytokine cascades by disrupting the interaction of these cytokines with a shared cell-surface receptor chain, IL-12Rβ1. The cytokines IL-12 and IL-23 have been implicated as important contributors to the chronic inflammation that is a hallmark of Crohn’s disease and ulcerative colitis. In animal models of colitis, genetic absence or antibody blockade of the p40 subunit of IL-12 and IL-23, the target of ustekinumab products, was shown to be protective.
Targets
IL-12 (p35), IL-23 (p19)
Storage
—
Approved
psoriasis — FDA
In trial
psoriasis, atopic dermatitis, alopecia areata, acne vulgaris
Last verified
2026-04-23
Mechanism of action
Stelara label (FDA, 2024)drugtargetsignalingeffectorcellularphenotype⊣ red bar = blocked/reduced by drug
Monitoring & workup
Baseline workup
- •TB IGRA (or PPD)
- •HBV sAg if high risk; HCV Ab if high risk
- •Update age-appropriate vaccines before start
Ongoing monitoring
- •No routine labs
- •Annual TB screening if high exposure risk
- •IL-17 class: monitor for candida overgrowth + IBD flare
- •IL-23 class: monitor for injection-site reactions