2025 British Society for Rheumatology guidelines on axial spondyloarthritis

Reference: June 2025 | Issue 6 | Vol 11 | Page 16

In April 2025, the British Society for Rheumatology (BSR) published new guidelines on the treatment of axial spondyloarthritis (axSpA) with biologic and targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs).¹

Pharmacological treatment options and strategies for axSpA have expanded since the last version of the guidelines was published in 2017.² Alongside these therapeutic developments, there have been rapid advancements in the treatment of extra-musculoskeletal manifestations (EMMs) as index conditions.

This guideline does not cover the use of NSAIDs, glucocorticoids, or conventional synthetic DMARDs; the treatment of enthesitis/spondylitis-related juvenile idiopathic arthritis; axial disease in psoriatic arthritis; safety of targeted therapies; or health economic considerations.

The document stipulates that there is no evidence to support recommending one class or drug over another with respect to efficacy for musculoskeletal manifestations. The decision to escalate to targeted therapies and the choice of therapy should be made with the person with axSpA and after considering prognostic factors, comorbidities, and EMMs. These adverse prognostic factors for radiographic structural progression should be considered as part of shared decision-making when initiating targeted therapies.

For the purpose of escalation to targeted therapies, active disease should be defined after appropriate use of non-pharmacological and conventional pharmacological therapies, and following verification of the diagnosis and inflammatory disease activity by a consultant rheumatologist. The British Society for Rheumatology says the “necessary push to reduce diagnostic delay must be cautiously balanced against the potential for misdiagnosis”.

The decision to initiate therapy should not be solely based on disease indices, the guidelines state. Nevertheless, validated measures of disease activity should be documented at the time of treatment initiation and at each follow-up. According to the document, the Axial Spondyloarthritis Disease Activity Score (ASDAS) is the only instrument shown to correlate with radiographic progression, and the ASDAS definition of high disease activity (≥2.1) better predicts treatment response than the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥4. For these reasons, the BSR recommends transitioning towards regular inclusion of ASDAS in clinical practice.

The absence of response to targeted therapies should prompt reassessment. It is recommended that assessments should consider compliance and whether residual symptoms are related to active inflammation. Follow-up assessment of disease activity should be holistic and supported by, but not solely reliant on, disease indices. The decision to continue therapy should be made jointly between the person with axSpA and the treating clinician.

The nature and interval of follow-up can be adjusted based on individual circumstances but should be reviewed at each visit to ensure it remains appropriate. Patient-initiated follow-up or extended follow-up intervals may be considered if the condition is well controlled and the patient has adequate education and access to local rheumatology advice and clinical support. In general, follow-up intervals should not exceed 24 months.

BASDAI 50 per cent or two-unit reduction and two-unit reduction in spinal pain continues to be the cornerstone of assessment, but the document defines an ASDAS reduction of ≥1.1 as a clinically important response.

Repeat imaging may help to assess inflammation and other causes of persistent symptoms. Clinicians should remain open to re-evaluating the original diagnosis, particularly when there is repeated non-response to targeted therapies.

There is currently insufficient evidence to recommend a specific sequence of targeted therapies in the case of treatment failure. In the context of verified diagnosis and inflammatory disease activity, the guidelines suggest that there should not be a limit to the number of sequential therapies that any individual can have.

For moderate to severe or recurrent uveitis, the decision to commence a targeted therapy should be jointly made between rheumatology and ophthalmology as part of an multi-disciplinary team. The guidelines cite trial data which do not suggest that IL-17Ai is harmful for uveitis. It is recommended that if uveitis develops or flares in individuals with well-controlled axSpA on etanercept or IL-17Ai, the severity and/or frequency of uveitis should be considered in consultation with an ophthalmologist before automatically switching therapy.

In people with well-controlled axSpA, inadequately controlled psoriasis does not necessarily require a change in targeted therapy, according to the British Society for Rheumatology. Where axSpA and psoriasis are both indications for targeted therapy, control of cutaneous psoriasis can be achieved by, in order of efficacy, IL-17 inhibitors, monoclonal TNF inhibitors or etanercept. The guidelines recommend using at least one objective measure for assessing and monitoring psoriasis.

In well-controlled axSpA, mild inflammatory bowel disease (IBD) may be managed without a change in targeted therapy. Monoclonal TNF or JAK inhibitors are preferred in people with active axSpA and IBD where advanced therapies are indicated. IL-17 inhibitors should not be commenced in people with active IBD, as it may exacerbate intestinal inflammation.

IL-17 inhibitors can still be considered in the context of well-controlled IBD when no other options are available, but the balance of risk and benefit in these circumstances should be carefully considered, with input from gastroenterology. If an IL-17 inhibitor is used, patients should be regularly monitor for symptoms compatible with IBD.  

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