JAK Inhibitor Improves Symptoms in Patients With Psoriatic Arthritis and Axial Involvement

In two phase 3 studies, patients with active psoriatic arthritis (PsA) and axial involvement demonstrated greater improvement in axial symptoms with upadacitinib compared with placebo, and similar or greater responses with upadacitinib compared with adalimumab. Researchers published findings from their post-hoc analysis online in Arthritis Research & Therapy.

“These data provide important information for treating clinicians on the efficacy and safety of upadacitinib 15 mg in axial disease and may help guide treatment decisions for PsA patients with axial involvement,” researchers wrote.

The analysis, which focused on patients with PsA and axial involvement from the SELECT-PsA 1 and SELECT-PsA 2 trials, defined baseline axial involvement in two ways: by investigator judgement alone, or by investigator judgement plus patient-reported outcome (PRO) criteria (specifically, scores of 4 or higher on the overall Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] and BASDAI question 2, which addresses the level of ankylosing spondylitis neck, back, or hip pain).

Among trial participants, 30.9% from SELECT-PsA 1 and 35.7% from SELECT-PsA 2 had axial involvement as determined by investigator judgement alone. Rates of participants with axial involvement by investigator judgement and PRO-based criteria were 22.6% in SELECT-PsA 1 and 28.6% in SELECT-PsA 2.

The trials randomized patients to upadacitinib 15 mg or placebo — or, in the case of SELECT-PsA 1, adalimumab 40 mg.

In SELECT-PsA 1, proportions of patients with axial involvement determined by investigator judgement alone who achieved BASDAI50 at week 24 were 59% with upadacitinib 15 mg, 26.9% with placebo, and 44.1% with adalimumab 40 mg. Rates of patients with axial involvement determined by investigator judgement plus PRO criteria were 60.4% with upadacitinib 15 mg, 29.3% with placebo, and 47.1% with adalimumab 40 mg, according to the analysis. Findings were comparable for SELECT-PsA 2. 

For additional BASDAI and Ankylosing Spondylitis Disease Activity Score endpoints, comparable improvements with upadacitinib 15 mg were observed at weeks 12 and 24, the study found, and were maintained at week 56. Meanwhile, safety was similar for patients with and without axial involvement.

Reference: 

Baraliakos X, Ranza R, Östör A, et al. Efficacy and safety of upadacitinib in patients with active psoriatic arthritis and axial involvement: results from two phase 3 studies. Arthritis Res Ther. 2023;25(1):56. doi:10.1186/s13075-023-03027-5