General Information

Stelara (ustekinumab) is a human IgG1k monoclonal antibody that binds with high affinity and specificity to the p40 protein subunit used by both the interleukin (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.
Stelara is specifically indicated for the the treatment of adult patients (18 years or older) with moderate to severe plaque psoriasis who are candidates for phototherapy or systemic therapy.
Stelara is supplied as a solution for subcutaneous injection. The recommended initial dose of the drug is as follows:
For patients weighing ≤100 kg (220 lbs): 45 mg initially and 4 weeks later, followed by 45 mg every 12 weeks.
For patients weighing >100 kg (220 lbs): 90 mg initially and 4 weeks later, followed by 90 mg every 12 weeks. The 45 mg dose was also shown to be efficacious in this population. However, 90 mg resulted in greater efficacy in these subjects.

Clinical Results

FDA Approval
The FDA approval of Stelara was based on two multicenter, randomized, double-blind, placebo-controlled studies: STUDY 1 (n=766) and STUDY 2 (n=1,230). All subjects were 18 years of age and older with plaque psoriasis over a minimum body surface area of 10%, and Psoriasis Area and Severity Index (PASI) score >12, and who were candidates for phototherapy or systemic therapy. In both studies, subjects were randomized to the following groups: placebo at Weeks 0 and 4 followed by crossover to Stelara (either 45 mg or 90 mg) at Weeks 12 and 16; or Stelara 45 mg or 90 mg doses, regardless of weight, at Weeks 0, 4, and 16. In both studies, the endpoints were the proportion of subjects who achieved at least a 75% reduction in PASI score (PASI 75) from baseline to Week 12 and treatment success (cleared or minimal) on the Physician’s Global Assessment (PGA). In STUDY 1, the PASI75 response was reached by 3%, 67% and 66% of the placebo and Stelara 45 mg and 90 mg doses, respectively. The PGA of Cleared or Minimal was reached by 4%, 59% and 61% of the placebo, Stelara 45 mg and 90 mg doses, respectively. Subjects in STUDY 1 were evaluated through Week 52. At Week 40, those who were PASI 75 responders at both Weeks 28 and 40 were re-randomized to either continued dosing of Stelara at Week 40 or to withdrawal of therapy (placebo at Week 40). At Week 52, 89% of subjects re-randomized to Stelara treatment were PASI 75 responders compared with 63% of subjects re-randomized to placebo (treatment withdrawal after Week 28 dose). In STUDY 2, the PASI75 response was reached by 4%, 67% and 76% of the placebo and Stelara 45 mg and 90 mg doses, respectively. The PGA of Cleared or Minimal was reached by 4%, 68% and 73% of the placebo, Stelara 45 mg and 90 mg doses, respectively. In subjects who weighed <100 kg, response rates were similar with both the 45 mg and 90 mg doses; however, in subjects who weighed >100 kg, higher response rates were seen with 90 mg dosing compared with 45 mg dosing.

Side Effects

Adverse events associated with the use of Stelara may include, but are not limited to, the following:
•    Nasopharyngitis
•    Upper respiratory tract infection
•    Headache
•    Fatigue