Details of the studies
In the PrevAS trial, Tamara Rusman, a PhD candidate in Rheumatology at the VU University Medical Center Amsterdam and coinvestigators studied patients meeting Calin criteria for inflammatory back pain who had high disease activity plus either HLA-B27 positivity with at least one feature of axial spondyloarthritis or HLA-B27 negativity with two features.
This population is of interest because “most studies have included only patients with nonradiographic axial spondyloarthritis with a positive MRI of the sacroiliac joints and/or an elevated C-reactive protein level,” she noted.
Results showed that, during 16 weeks of treatment, etanercept users had a nonsignficantly higher rate of achieving an ASAS 20 response with etanercept versus placebo users (17% vs. 11%; hazard ratio, 2.1; P = .2). The etanercept group also had a somewhat higher rate of response as defined by the Ankylosing Spondylitis Disease Activity Score CRP (ASDAS-CRP) criterion (25% vs. 13%; hazard ratio, 1.1; P = .8).
“Based on these data, early treatment in inflammatory back pain patients prone to develop axial spondyloarthritis seems not to be useful,” Ms. Rusman concluded. “However, monitoring of these patients should be continued since they remain a risk group for developing axial spondyloarthritis.”
Dr. Filip Van den Bosch
In the RE-EMBARK trial, investigators led by Filip Van den Bosch, MD, PhD, Rheumatology Head-of-Clinic at Ghent (Belgium) University Hospital, started with a cohort of 208 patients with nr-axSpA who were given etanercept and background NSAIDs for 24 weeks.
“Current guidelines do not agree on whether a TNF-blocking agent or another biological DMARD should be tapered once a status of low disease activity or remission is achieved,” he noted.
Overall, 59% of the patients achieved inactive disease (defined as an ASDAS-CRP < 1.3) and discontinued etanercept.
During the next 40 weeks, 24% of these patients maintained inactive disease with only the background NSAID therapy. Among the 75% who experienced a flare, defined as an ASDAS with erythrocyte sedimentation rate (ASDAS-ESR) score of 2.1 or greater, the median time to flare was 16.1 weeks. Fully 62% of this group were able to regain disease inactivity within 12 weeks of restarting etanercept.
In a comparative analysis, relative to the RE-EMBARK patients discontinuing etanercept, similar patients who continued etanercept on the companion EMBARK trial had a longer time to flare (P < .0001) and an 85% lower risk of this outcome.
“There were no new safety signals identified, and as expected, the number of treatment-emergent adverse events dropped during the drug-free period and, interestingly, remained stable over retreatment,” Dr. Van den Bosch noted.
“Temporarily discontinuing etanercept may be an option for some patients with stable inactive nonradiographic axial spondyloarthritis,” he concluded.
The PrevAS trial was financially supported by Pfizer and ReumaNederland. Ms. Rusman declared no relevant conflicts of interest; four coauthors reported financial relationship(s) with Pfizer and other pharmaceutical companies. The RE-EMBARK trial was sponsored by Pfizer. Dr. Van den Bosch disclosed receiving grant/research support from AbbVie, Merck, and UCB, and consulting fees from AbbVie, Bristol-Myers Squibb, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB. Four coauthors reported financial ties to Pfizer and other pharmaceutical companies, and five coauthors were employees and shareholders of Pfizer.
SOURCES: Rusman T et al. Ann Rheum Dis. 2020;79[suppl 1]:72-3; and Van den Bosch F et al. Ann Rheum Dis. 2020;79[suppl 1]:70.