ATLANTA – in the randomized, placebo-controlled, phase 2/3 SELECT-AXIS 1 study.
Dr. Désirée van der Heijde
Physical functioning and imaging measures also were improved with upadacitinib in the double-blind, multicenter study, Désirée van der Heijde, MD, PhD, reported at the annual meeting of the American College of Rheumatology.
The findings are notable because patients with ankylosing spondylitis (AS) who have an inadequate response or contraindication to NSAIDs have limited treatment options other than biologic disease-modifying antirheumatic drugs (bDMARDs). The JAK pathway has emerged as a potential therapeutic target in AS, and given its recent approval for the treatment of RA as well as ongoing studies of the agent for several other chronic immune-mediated inflammatory diseases, Dr. van der Heijde and colleagues sought to assess its efficacy and safety in bDMARD-naive patients with active AS.
Of 93 AS patients aged 18 years and older who were randomized to receive 15 mg of upadacitinib daily, 51.6% achieved the primary study endpoint of 40% improvement in Assessment of Spondyloarthritis International Society response criteria (ASAS 40) at week 14, compared with 25.5% of 94 patients who received placebo, said Dr. van der Heijde, professor of rheumatology at Leiden (the Netherlands) University Medical Center.
The effect was rapid, with a clear difference emerging between the treatment and placebo groups within 2 weeks, she noted.
Significant improvements were also seen with upadacitinib for several key secondary endpoints including change from baseline to week 14 in the Ankylosing Spondylitis Disease Activity Score, Spondyloarthritis Research Consortium of Canada MRI Spine, a 50% improvement of the initial Bath Ankylosing Spondylitis Disease Activity Index (BASDAI 50), ASAS partial remission, and Bath Ankylosing Spondylitis Functional Index.
SELECT-AXIS 1 patients were adults with a mean age of 45 years who were enrolled from 60 sites in 20 countries. All met modified New York criteria for AS based on central reading of radiographs, had a BASDAI score of at least 4, had a patient assessment of total back pain of 4 or greater on a 0-10 scale at screening and baseline, were naive to bDMARDs, and had either an inadequate response to at least two NSAIDs or an intolerance/contraindication to NSAIDs.
Most patients (70.6%) were men, and 76.5% were HLA-B27 positive. Mean symptom duration was 14-15 years, and mean disease duration was 7-8 years, Dr. van der Heijde said, adding that baseline disease characteristics were balanced between the two arms.
All randomized patients received their assigned treatment, and 95.7% completed the study through week 14, including 90 of 94 placebo group patients and 89 of 93 upadacitinib patients.
“Treatment was generally well tolerated,” she said.
The proportions of patients in the treatment and placebo groups, respectively, were similar with respect to adverse events leading to discontinuation (2.2% vs. 3.2%), serious adverse events (1.1% in each group), and infections (20.4% vs. 27.7%). No serious infections, herpes zoster, malignancy, venous thromboembolic events, or deaths were reported. Also, no differences were seen between the groups in relevant laboratory abnormalities, and no new safety finding were observed in comparison with previous upadacitinib studies in other diseases, she noted.
Dr. van der Heijde concluded that “these results support further investigation of upadacitinib for the treatment of ankylosing spondyloarthritis.”
AbbVie, which markets upadacitinib, funded the study. Dr. van der Heijde disclosed financial relationships with AbbVie and 20 other pharmaceutical companies. Many other authors also reported financial relationships with industry, including AbbVie.
SOURCE: van der Heijde D et al. Arthritis Rheumatol. 2019;71(suppl 10), Abstract 2728.