Summary

2019 ACR/SAA/SPARTAN update of the 2015 recommendations for treatment of ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA), focused on positioning of newer agents (secukinumab, ixekizumab, tofacitinib, TNFi biosimilars) and the role of imaging. NSAIDs and TNFi remain first-line pharmacologic therapy; IL-17 inhibitors are preferred over a second TNFi in primary TNFi non-responders, while a second TNFi is preferred for secondary non-response. New recommendations address against treat-to-target with ASDAS, against routine biologic tapering/discontinuation in stable disease, against mandated switching to a biosimilar, and against scheduled serial spine radiographs.

Key Recommendations

For active AS/nr-axSpA, use continuous NSAIDs over on-demand; switch to on-demand once disease is stable.
For active disease despite NSAIDs, strongly recommend TNFi over no TNFi; no particular TNFi preferred for typical patients.
Use TNFi over secukinumab/ixekizumab as the first biologic, and use TNFi/secukinumab/ixekizumab over tofacitinib.
In primary non-response to first TNFi, switch to secukinumab or ixekizumab rather than to a different TNFi.
In secondary non-response to first TNFi, switch to a different TNFi rather than to a non-TNFi biologic.
Strongly recommend against switching to a biosimilar of the same TNFi after failure, and against mandated switching from originator TNFi to biosimilar in stable patients.
Do not co-administer low-dose methotrexate with TNFi routinely; sulfasalazine or methotrexate reserved for prominent peripheral arthritis or when TNFi unavailable/contraindicated.
In patients with contraindications to TNFi (CHF, demyelinating disease), prefer secukinumab/ixekizumab; if contraindication is infection risk/TB, prefer sulfasalazine.
For AS with recurrent uveitis or coexisting IBD, prefer TNFi monoclonal antibodies (adalimumab, infliximab) over etanercept and over IL-17 inhibitors (which can worsen IBD).
Strongly recommend against systemic glucocorticoids; do not discontinue or routinely taper biologics in stable disease.
Conditionally recommend against treat-to-target using ASDAS <1.3 (or <2.1); against routine serial spine radiographs (e.g., every 2 years).
Obtain spine/pelvis MRI when disease activity is unclear on a biologic; do not obtain MRI to confirm inactivity in clinically stable patients.

Thresholds & Doses

Adequate NSAID trial before escalating to TNFi: ≥2 different NSAIDs at maximal doses over 1 month, or incomplete response to ≥2 NSAIDs over 2 months.
Stable disease definition: asymptomatic or symptoms at acceptable level for minimum 6 months.
Primary non-response: no clinically meaningful improvement at 3-6 months after initiation.
Secondary non-response: relapse generally beyond initial 6 months of treatment.
Treat-to-target ASDAS targets not recommended: ASDAS <1.3 (inactive) or <2.1 (low activity).
Etanercept tapering studied: 25 mg weekly vs 50 mg weekly — tapering associated with somewhat less remission.
TNFi discontinuation in remission: relapse in 60-74% of patients, sometimes within weeks to months.
Second TNFi after failure of first: ~25-40% achieve meaningful response (e.g., 50% BASDAI improvement).
Spine radiographs detect change in 20-35% of AS patients over 2-year intervals — not recommended as routine monitoring.

Citations

Table 2 (Recommendations 1-51) — AS treatment recommendations including NSAIDs, TNFi, IL-17i, and imaging.
Table 3 (Recommendations 52-86) — nr-axSpA treatment recommendations parallel to AS.
Section A (PICO 7, 58, 59, 60, 61) — Positioning of sulfasalazine/MTX/tofacitinib and IL-17 inhibitors vs TNFi.
Section A (PICO 10) — Primary vs secondary TNFi non-response strategy (IL-17i vs second TNFi).
Section B (PICO 63, 65, 66) — Originator vs biosimilar switching, tapering and discontinuation of biologics in stable disease.
Section C (PICO 29, 32) — Uveitis and IBD: TNFi monoclonal antibodies preferred.
Section E (PICO 67, 68, 69, 70) — Against treat-to-target ASDAS, MRI use in unclear activity, against scheduled serial spine radiographs.
Table 1 — Definitions of active/stable disease, primary/secondary non-response, csARD, biosimilar.