NEW YORK (Reuters Health)—The anti-interleukin (IL)-12/IL-23 monoclonal antibody ustekinumab improves signs and symptoms of spondylitis in patients with psoriatic arthritis, according to a post-hoc analysis of data from the PSUMMIT-1 and PSUMMIT-2 trials.
“This treatment did seem to have a benefit on axial symptoms,” Dr. Arthur Kavanaugh from the University of California San Diego, La Jolla, Calif., tells Reuters Health by email. “Right now, it is approved for psoriatic arthritis treatment; it has a particularly strong effect on skin psoriasis, so is worth considering in such patients, although the biologic agents patients typically go to first are the [tumor necrosis factor] TNF-inhibitors.”
As many as 30% of patients with psoriasis also have psoriatic arthritis, and 25% to 75% of patients with psoriatic arthritis have inflammatory axial involvement/spondylitis.
Dr. Kavanaugh and colleagues assessed the efficacy and safety of ustekinumab in 256 psoriatic arthritis patients with peripheral arthritis and physician-reported spondylitis who had participated in the two Phase 3 studies that supported the regulatory approval of ustekinumab for psoriatic arthritis.
Significantly more patients treated with ustekinumab (54.8%) than with placebo (32.9%) achieved at least a 20% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI20) at Week 24, according to the April 20 Annals of the Rheumatic Diseases online report.
Ustekinumab-treated patients were also more likely than placebo-treated patients to achieve BASDAI50 (29.3% vs. 11.4%, respectively) and BASDAI70 (15.3% vs. 0%, respectively).
At Weeks 12 and 24, ustekinumab-treated patients experienced significant improvements in Ankylosing Spondylitis Disease Activity Score incorporating C-reactive protein (ASDAS-CRP), as well with mean improvements approaching 30% at Week 24 vs. <5% with placebo.
As expected, ustekinumab-treated patients were more likely than placebo-treated patients to show significant improvements and other measures of psoriatic arthritis. Ustekinumab also brought greater improvements in physical function, quality of life and radiographic progression, compared with placebo.
Adverse event rates were comparable between the treatment arms, including all adverse events, serious adverse events, discontinuations due to adverse events and infections.
“[Although] interesting, these data need to be replicated formally,” Dr. Kavanaugh concludes.
Janssen Research and Development funded studies for data in this analysis and employed four coauthors. Three other coauthors reported disclosures.