Conference Coverage

Comorbid spondyloarthritis and fibromyalgia lower response to TNF inhibitors


Key clinical point: Comorbid axial spondyloarthritis and fibromyalgia are associated with a lower response to biologic therapy.

Major finding: About 35% vs. 45% of patients who did and did not meet research criteria for fibromyalgia had an ASAS20 response at 3 months.

Study details: Data on 1,750 participants of the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis (BSRBR-AS).

Disclosures: The BSRBR-AS is funded by the British Society for Rheumatology, which in turn receives funding from AbbVie, Pfizer, and UCB. Dr. Macfarlane did not provide any disclosures but has previously acknowledged receiving an honorarium from Pfizer and research funding from AbbVie and Pfizer for the Scotland Registry for Ankylosing Spondylitis study.

Source: Macfarlane GJ et al. Rheumatology. 2018;57(Suppl. 3):key075.183.



– Individuals with axial spondyloarthritis (axSpA) who have comorbid fibromyalgia do respond to biologic therapy but at a seemingly lower rate if they have a high symptom score during early assessments.

Data from the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis (BSRBR-AS) showed that participants with axSpA who were starting biologic therapy with a tumor necrosis factor inhibitor (TNFi) for the first time also had worse disease activity at baseline if they met fibromyalgia research criteria than if they did not.

Dr. Gary Macfarlane, clinical chair in epidemiology at the University of Aberdeen, Scotland Sara Freeman/MDedge News

Dr. Gary Macfarlane

These findings show that there are “considerable unmet needs” for patients with axSpA and comorbid fibromyalgia, even though they had some improvement, Gary J. Macfarlane, MBChB, PhD, the BSRBR-AS’s chief investigator, reported at the British Society for Rheumatology annual conference.

“The issue of fibromyalgia as a comorbidity in axial SpA has been the subject of current considerable interest,” said Dr. Macfarlane, who is Clinical Chair in Epidemiology at the University of Aberdeen (Scotland), where the BSRBR-AS is run. This is for several reasons: “One is the challenge of identifying patients with axial SpA who have comorbid fibromyalgia.

“The second is the concern that comorbid fibromyalgia may have an effect on disease indices such as BASDAI [Bath Ankylosing Spondylitis Disease Activity Index],” Dr. Macfarlane observed.

This leads to the third issue: “Are patients with comorbid fibromyalgia inappropriately receiving biological therapy, and how do they respond if they do receive it?”

Previous data from the BSRBR-AS have shown that approximately one in five patients with axSpA meet research criteria for fibromyalgia (Arthritis Rheumatol. 2017;69:2144-50) and that the prevalence of the comorbidity was higher in those who met Assessment of SpondyloArthritis International Society imaging criteria and lower in those who only met clinical criteria (25% vs. 10%).


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