STELARA® (ustekinumab)

Study Design

PSUMMIT I was a multicenter, randomized, double-blind, placebo-controlled study in 615 adult patients with active PsA for ≥6 months despite treatment with nonsteroidal anti-inflammatory drug (NSAID) or disease-modifying antirheumatic drug (DMARD) therapy; patients were biologic-naïve. PSUMMIT II was a multicenter, randomized, double-blind, placebo-controlled study in 312 adult patients with active PsA for ≥6 months, despite current or previous DMARD and/or NSAID therapy, and who may have been previously treated with biologic anti-TNF agent(s). In both studies, active PsA was defined as ≥5 swollen joints, ≥5 tender joints, and C-reactive protein ≥0.3 mg/dL. Patients had active plaque psoriasis, or a documented history of plaque psoriasis, and could be categorized in at least 1 of the PsA subsets (distal interphalangeal joint involvement, polyarticular arthritis with absence of rheumatoid nodules, arthritis mutilans, asymmetric peripheral arthritis, or spondylitis with peripheral arthritis). Stable doses (≤25 mg/week) of MTX at study entry, stable oral corticosteroid doses equivalent to ≤10 mg/day of prednisone, and NSAIDs were permitted. Patients were randomized to receive STELARA^® 45 mg, STELARA^® 90 mg, or placebo as subcutaneous (SC) injection at Weeks 0 and 4 and every 12 weeks thereafter. At Week 16, subjects with <5% improvement from baseline in both tender and swollen joint counts in the 45-mg and placebo groups were eligible for early escape and received STELARA^® 90 mg and 45 mg, respectively. Subjects randomized to placebo who did not qualify for early escape were to cross over to receive STELARA^® 45 mg at Weeks 24 and 28, followed by dosing every 12 weeks thereafter. The primary endpoint was the percentage of patients achieving ACR20 response at Week 24.^1-4

In this intent-to-treat analysis, patients were considered treatment failures if they initiated any protocol-prohibited medications, increased the dose of MTX or oral corticosteroids above baseline, or discontinued study agent due to unsatisfactory therapeutic effect for PsA, or an adverse event (AE), or worsening of PsA prior to Week 24. Missing data last observation carried forward rules were applied. The patients who early escaped at Week 16 were considered treatment failures and had Week 16 data carried forward through Week 24.^2,3