Big Gains at 2 Years of Ustekinumab in PsA

Patients with psoriatic arthritis (PsA), including those with axial involvement, achieve significant improvements in signs and symptoms with the interleukin-12/23 inhibitor ustekinumab (Stelara), and they  -- maintain those gains for 2 years, according to final results from 3 major clinical trials.

Of the 615 patients with active PsA randomized to either 45 mg or 90 mg of subcutaneous ustekinumab or placebo in the phase 3 PSUMMIT1 trials, more than half show a 20% improvement in ACR20 scores, especially on the higher dose.

Ustekinumab also produces and maintains similar improvements in ACR50 and ACR70 responses in PsA, as well as in radiographic progression, researchers write online in Arthritis Care and Research.

Among a subgroup of PsA patients with spondylitis and peripheral joint involvement (n=186), almost 60% achieved a 20% improvement in spinal symptoms on the higher dose of ustekinumab according to the Bath Ankylosing Spondyloarthritis Disease Activity Score (BASDAI). These gains were maintained over 100 weeks.

The subgroup analysis, reported at EULAR 2015, also shows that ustekinumab significantly improves enthesitis, dactylitis, skin scores, and peripheral radiographic progression at 6 months. The safety and efficacy profile was similar to that of the entire ustekinumab-treated PSUMMIT cohort.

The subgroup analysis is important, the researchers told the EULAR meeting, because the IL-12 pathway is thought to play a major role in spondyloarthritis.

In the 3 PSUMMIT trials, 615 patients with active PsA were randomized to placebo, ustekinumab 45 mg or 90 mg, at weeks 0, 4, and every 12 weeks through week 88 (the last dose).

At 16 weeks, patients with less than a 5% improvement in both tender and swollen joint counts were blinded to early “escape,” either placebo to 45 mg ustekinumab or 45 mg-90 mg of ustekinumab. All remaining placebo patients crossed over to ustekinumab 45 mg at week 24.

Clinical efficacy measures include responses at or above ACR20, 28-joint count disease activity score/C-reactive protein (DAS28-CRP), and at or above 75% improvement in the psoriasis area and severity index (PASI75). Radiographic progression was evaluated using the van der Heijde-modified Sharp (vdH-S) score.

At 100 weeks, DAS28 and PAS175 responses hit over 75% across treatment groups and in both ustekinumab groups -- the median percent improvement in dactylitis and enthesitis was 100%.

References:

Arthur Kavanaugh A, Puig L, Gottlieb AB, et al. Maintenance of clinical efficacy and radiographic benefit through 2 years of ustekinumab therapy in patients with active psoriatic arthritis: Results from the PSUMMIT 1 trial. Arthritis Care & Research.Accepted Article. Online June 19 2015. DOI: 10.1002/acr.22645.

Arthur Kavanaugh A, Puig L, Gottlieb AB, et al., Efficacy and safety of ustekinumab in psoriatic arthritis patients with spondylitis and peripheral joint involvement: results from a phase 3, multicenter, double-blind, placebo-controlled study. EULAR 2015 Abstract OP0174. 10.1136/annrheumdis-2015-eular.3096