Ustekinumab is a human IgG1қ monoclonal antibody 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 was 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, was shown to be protective.

STELARA® is a human interleukin-12 and -23 antagonist indicated for the treatment of: Adult patients with: moderate to severe plaque psoriasis (PsO) who are candidates for phototherapy or systemic therapy; active psoriatic arthritis (PsA); moderately to severely active Crohn's disease (CD); moderately to severely active ulcerative colitis. Pediatric patients 6 years and older with: moderate to severe plaque psoriasis, who are candidates for phototherapy or systemic therapy; active psoriatic arthritis (PsA).

Plaque Psoriasis: Subcutaneous Adult Dosage Regimen: For patients weighing 100 kg or less, the recommended dose is 45 mg initially and 4 weeks later, followed by 45 mg every 12 weeks. For patients weighing more than 100 kg, the recommended dose is 90 mg initially and 4 weeks later, followed by 90 mg every 12 weeks. (See Full Prescribing Information.)

Most common adverse reactions are: Psoriasis (≥3%): nasopharyngitis, upper respiratory tract infection, headache, and fatigue. Crohn's Disease, induction (≥3%): vomiting. Crohn's Disease, maintenance (≥3%): nasopharyngitis, injection site erythema, vulvovaginal candidiasis/mycotic infection, bronchitis, pruritus, urinary tract infection, and sinusitis. Ulcerative colitis, induction (≥3%): nasopharyngitis. Ulcerative colitis, maintenance (≥3%): nasopharyngitis, headache, abdominal pain, influenza, fever, diarrhea, sinusitis, fatigue, and nausea.

Clinically significant hypersensitivity to ustekinumab or to any of the excipients in STELARA.

Infections: Serious infections have occurred. Avoid starting STELARA® during any clinically important active infection. If a serious infection or clinically significant infection develops, discontinue STELARA® until the infection resolves. Theoretical Risk for Particular Infections: Serious infections from mycobacteria, salmonella, and Bacillus Calmette-Guerin (BCG) vaccinations have been reported in patients genetically deficient in IL-12/IL-23. Consider diagnostic tests for these infections as dictated by clinical circumstances. Tuberculosis (TB): Evaluate patients for TB prior to initiating treatment with STELARA®. Initiate treatment of latent TB before administering STELARA®. Malignancies: STELARA® may increase risk of malignancy. The safety of STELARA® in patients with a history of or a known malignancy has not been evaluated. Hypersensitivity Reactions: If an anaphylactic or other clinically significant hypersensitivity reaction occurs, institute appropriate therapy and discontinue STELARA®. Posterior Reversible Encephalopathy Syndrome (PRES): If PRES is suspected, treat promptly, and discontinue STELARA®. Immunizations: Avoid use of live vaccines in patients during treatment with STELARA®. Noninfectious Pneumonia: Cases of interstitial pneumonia, eosinophilic pneumonia, and cryptogenic organizing pneumonia have been reported during post-approval use of STELARA®. If diagnosis is confirmed, discontinue STELARA® and institute appropriate treatment.