Association of clinical response criteria and disease activity levels with axial spondyloarthritis core domains: results from two phase 3 randomised studies, BE MOBILE 1 and 2

OBJECTIVE

To assess how achievement of increasingly stringent clinical response criteria and disease activity states at week 52 translate into changes in core domains in patients with non-radiographic (nr-) and radiographic (r-) axial spondyloarthritis (axSpA).

METHODS

Patients in BE MOBILE 1 and 2 achieving different levels of response or disease activity (Assessment of SpondyloArthritis International Society (ASAS) and Ankylosing Spondylitis Disease Activity Score (ASDAS) response criteria, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50)) at week 52 were pooled, regardless of treatment arm. Associations between achievement of these endpoints and change from baseline (CfB) in patient-reported outcomes (PROs) measuring core axSpA domains, including pain, fatigue, physical function, overall functioning and health, and work and employment, were assessed.

RESULTS

Achievement of increasingly stringent clinical efficacy endpoints at week 52 was generally associated with sequentially greater improvements from baseline in all PROs. Patients with nr-axSpA achieving ASAS40 demonstrated greater improvements (CfB) than patients who did not achieve ASAS40 but did achieve ASAS20, in total spinal pain (-5.3 vs -2.8, respectively), Functional Assessment of Chronic Illness-Fatigue subscale (12.7 vs 6.7), Bath Ankylosing Spondylitis Function Index (-3.9 vs -1.8), European Quality of Life 5-Dimension 3-Level Version (0.30 vs 0.16), Work Productivity and Activity Impairment-axSpA presenteeism (-35.4 vs -15.9), overall work impairment (-36.5 vs -12.9), activity impairment (-39.0 vs -21.0) and sleep (9.0 vs 3.9). Results were similar for ASDAS and BASDAI50. Similar amplitudes of improvement were observed between patients with nr-axSpA and r-axSpA.

CONCLUSIONS

Patients treated with bimekizumab across the full axSpA disease spectrum, who achieved increasingly stringent clinical response criteria and lower disease activity at week 52, reported larger improvements in core axSpA domains.

Radiographic and non-radiographic axial spondyloarthritis are not routinely distinguished in everyday clinical care: an analysis of real-world data from rheumatology practices

The categorization of axial spondyloarthritis (axSpA) into radiographic (r-axSpA) and non-radiographic (nr-axSpA) subtypes is important in clinical trials but may be of less value in clinical practice. This exploratory cross-sectional, multi-center study evaluated patients with axSpA under routine care at German clinical rheumatology sites (RHADAR real-world database), with a focus on imaging data used for diagnostic classifications. Our analyses included 371 patients with axSpA. The mean (standard deviation [SD]) age was 50.9 (14.0) years, disease duration was 16.4 (13.5) years, and 39.6% were female. Based on the rheumatologist's final assessment, almost half of patients had definite r-axSpA (n = 179; 48.2%), 53 (14.3%) had suspected r-axSpA, 112 (30.2%) had non-radiographic-axSpA (nr-axSpA), and 27 (7.3%) had undefined axSpA. Patients assessed with definite or suspected r-axSpA were more likely to be treated with disease-modifying antirheumatic drugs (DMARDs) (62.0% and 64.2%, respectively) compared with nr-axSpA or undefined axSpA patients (37.5% and 48.1%, respectively). Almost all patients (348/371; 93.8%) had sacroiliac joint imaging data (radiographs or magnetic resonance imaging) documented in their charts, but only 216 (58.2%) had conventional radiographs required for formal diagnosis of r-axSpA by modified New York criteria. Follow-up radiographic imaging in nr-axSpA patients was uncommon (23/216 [25.0%]) but confirmed r-axSpA in 9/23 patients (39.1%). In conclusion, radiographs were available for slightly more than half of axSpA patients. Follow-up imaging was infrequent during rheumatology care in Germany but confirmed r-axSpA in ~ 40% of patients originally considered to have nr-axSpA. The distinction between r-axSpA and nr-axSpA may be ill-defined in routine clinical practice.

Patients' Perspectives on Axial Pain in Relation to Inflammation and Structural Damage in a Large Cohort of Axial Spondyloarthritis Patients

OBJECTIVE

The objective of this study was to explore to what extent patients with axial spondyloarthritis (axSpA) link experienced pain in the neck, back, and hips to inflammation and/or structural damage.

METHODS

Patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort visiting the outpatient clinic between 2016 and 2019 filled out two additional questions in relation to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) question 2: (1) "To what extent do you think the pain you experience in your neck, back, and hips is related to inflammation caused by axSpA?" and (2) "To what extent do you think the pain you experience in your neck, back, and hips is related to damage of the spine and joints caused by axSpA?" Answers had to be depicted on a numeric rating scale from 0 (none) to 10 (very much); a difference of ≥2 points between the scores of these questions was considered clinically relevant in favor of the highest scoring question.

RESULTS

A total of 688 patients with axSpA (24% with nonradiographic axSpA [nr-axSpA]) were included (62% male, mean ± SD age 48 ± 14 years, and mean ± SD Ankylosing Spondylitis Disease Activity Score [ASDAS] 2.3 ± 1.0). Seventy-five percent of patients could not link the origin of their pain, 15% linked axial pain predominantly to inflammation, and 10% linked axial pain predominantly to damage. Patients in the inflammation group were younger, had shorter symptom duration, were more frequently diagnosed with nr-axSpA, had higher ASDASCRP , had more often elevated CRP levels, had fewer comorbidities, had better spinal mobility, and had less spinal radiographic damage.

CONCLUSION

In our large observational cohort, the majority of patients with axSpA could not differentiate the origin of experienced axial pain. If patients were able to link axial pain to clinical inflammation or damage, it was in concordance with clinical assessments and radiographic outcome, which may be helpful in establishing the origin of pain and supporting better patient-centered treatment decisions.

Bone metabolism and inflammatory biomarkers in radiographic and non-radiographic axial spondyloarthritis patients: a comprehensive evaluation

Introduction

Axial spondyloarthritis (axSpA) is a heterogeneous disease that can be represented by radiographic axSpA (r-axSpA) and non-radiographic axSpA (nr-axSpA). This study aimed to evaluate the relationship between the markers of inflammation and bone turnover in r-axSpA patients and nr-axSpA patients.

Methods

A cross-sectional study included 29 r-axSpA patients, 10 nr-axSpA patients, and 20 controls matched for age and sex. Plasma markers related to bone remodeling such as human procollagen type 1 N-terminal propeptide (P1NP), sclerostin, tartrate-resistant acid phosphatase 5b (TRACP5b), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) were measured by an ELISA kit. A panel of 92 inflammatory molecules was analyzed by proximity extension assay.

Results

R-axSpA patients had decreased plasma levels of P1NP, a marker of bone formation, compared to controls. In addition, r-axSpA patients exhibited decreased plasma levels of sclerostin, an anti-anabolic bone hormone, which would not explain the co-existence of decreased plasma P1NP concentration; however, sclerostin levels could also be influenced by inflammatory processes. Plasma markers of osteoclast activity were similar in all groups. Regarding inflammation-related molecules, nr-axSpA patients showed increased levels of serum interleukin 13 (IL13) as compared with both r-axSpA patients and controls, which may participate in the prevention of inflammation. On the other hand, r-axSpA patients had higher levels of pro-inflammatory molecules compared to controls (i.e., IL6, Oncostatin M, and TNF receptor superfamily member 9). Correlation analysis showed that sclerostin was inversely associated with IL6 and Oncostatin M among others.

Conclusion

Altogether, different inflammatory profiles may play a role in the development of the skeletal features in axSpA patients particularly related to decreased bone formation. The relationship between sclerostin and inflammation and the protective actions of IL13 could be of relevance in the axSpA pathology, which is a topic for further investigation.

Long-term safety of Ixekizumab in adults with psoriasis, psoriatic arthritis, or axial spondyloarthritis: a post-hoc analysis of final safety data from 25 randomized clinical trials

BACKGROUND

We report long-term, end-of-study program safety outcomes from 25 randomized clinical trials (RCTs) in adult patients with psoriasis (PsO), psoriatic arthritis (PsA), or axial spondyloarthritis (axSpA) [including ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA)] who received ≥ 1 dose of Ixekizumab (IXE) over 5 years (PsO) or up to 3 years (PsA, axSpA).

METHODS

This integrated safety analysis consists of data from patients who received any dose of IXE, across 25 RCTs (17 PsO, 4 PsA, 4 axSpA). Rates of treatment-emergent adverse events (TEAEs), serious adverse events (SAEs) and selected adverse events (AEs) of interest were analyzed for all pooled studies by years of therapy and overall, through March 2022. Results were reported as exposure-adjusted incidence rates (IRs) per 100 patient-years (PY) overall and at successive year intervals.

RESULTS

Six thousand eight hundred ninety two adult patients with PsO, 1401 with PsA, and 932 with axSpA (including AS and nr-axSpA), with a cumulative IXE exposure of 22,371.1 PY were included. The most commonly reported TEAE across indications was nasopharyngitis (IRs per 100 PY: 8.8 (PsO), 9.0 (PsA), 8.4 (axSpA)). SAEs were reported by 969 patients with PsO (IR 5.4), 134 patients with PsA (IR 6.0), and 101 patients with axSpA (IR 4.8). Forty-five deaths were reported (PsO, n = 36, IR 0.2; PsA, n = 6, IR 0.3; axSpA, n = 3, IR 0.1). TEAEs did not increase during IXE exposure: IRs per 100 PY, PsO: 88.9 to 63.2 (year 0-1 to 4-5), PsA: 87 to 67.3 (year 0-1 to 2-3), axSpA: 82.1 to 55.4 (year 0-1 to >  = 2). IRs per 100 PY of discontinuation from IXE due to AE were 2.9 (PsO), 5.1 (PsA), and 3.1 (axSpA). IRs per 100 PY of injection site reactions were 5.9 (PsO), 11.6 (PsA) and 7.4 (axSpA); Candida: 1.9 (PsO), 2.0 (PsA), and 1.2 (axSpA); depression, major adverse cerebro-cardiovascular events and malignancies: ≤ 1.6 across all indications. Adjudicated IRs per 100 PY of inflammatory bowel disease were ≤ 0.8 across indications (0.1 [PsO]; 0.1 [PsA]; 0.8 [axSpA]).

CONCLUSIONS

In this integrated safety analysis, consisting of over 22,000 PY of exposure, the long-term safety profile of IXE was found to be consistent with previous, earlier reports, with no new safety signals identified.

TRIAL REGISTRATION

NCT registration numbers for RCTs included in this integrated analysis can be found in Additional File 1.

Upadacitinib for the treatment of adults with active non-radiographic axial spondyloarthritis (nr-axSpA)

INTRODUCTION

Non-radiographic axial spondyloarthritis (nr-axSpA) is a chronic inflammatory condition with axial and peripheral musculoskeletal involvement, fulfilling criteria of axSpA in the absence of advanced radiographic sacroiliitis. While appropriate treatment is required for chronic pain and disability resulting from disease progression, the limited availability of treatment options becomes evident. Upadacitinib, an oral selective Janus kinase 1 inhibitor, was approved in Europe, the United States, and other countries for management of nr-axSpA with inadequate response to existing therapies.

AREA COVERED

This review summarizes essential drug profiles, efficacy, and safety of upadacitinib for nr-axSpA in conjunction with data pertaining to radiographic axSpA.

EXPERT OPINION

In a phase 3 trial, upadacitinib exhibited efficacy for patients with nr-axSpA, irrespective of prior exposures to biological disease-modifying antirheumatic drugs (bDMARDs). The safety profiles of upadacitinib in nr-axSpA mirrored those in other indications, underscoring its potential as a promising treatment option for nr-axSpA. Concurrently, physicians should be aware of the absence of real-world data, longitudinal efficacy and safety, direct comparative studies between upadacitinib and bDMARDs in nr-axSpA, and evidence for precision medicine to identify patients who may optimally benefit from upadacitinib over bDMARDs. Future research is imperative to facilitate the effective utilization of upadacitinib in daily clinical practice.

Is tapering or discontinuation of biologic treatment in patients with radiographic and nonradiographic axial spondyloarthritis reasonable? : A local cohort study

OBJECTIVE

We retrospectively determined factors predicting biologic treatment discontinuation or tapering in patients with axSpA.

MATERIALS AND METHODS

We included 63 nonradiographic axSpA (nr-axSpA) and 138 radiographic axSpA (r-axSpA) patients on biologic treatments for at least 1 year. The biologic dosing intervals were increased in patients who had been in remission for at least 6 months. In patients whose biologic dosing intervals could be increased by 100% for at least 6 months, the agents were stopped at the end of that time. In patients for whom the biologic agents were stopped or tapered, relapse was defined as a Bath Ankylosing Spondylitis Disease activity index score > 4 and a CRP level > 10 mg/L.

RESULTS

The median duration of biologic treatment (all patients) was 2 (1-11) years. Logistic regression analysis did not identify any independent predictor of treatment discontinuation. NSAID use was the only independent predictor of tapering (p = 0.001). The time to relapse after tapering was shorter in patients with r‑axSpA than nr-axSpA (25.97 vs. 39.53 months; p = 0.05). The time to relapse in patients with r‑axSpA was considerably shorter than that in patients with nr-axSpA (5.14 vs. 13 months; p = 0.001). All r‑axSpA patients relapsed over the follow-up period; only 2 nr-axSpA patients did not relapse.

CONCLUSION

The most significant independent predictor of relapse was NSAID use during treatment. For axSpA patients in remission, tapering of the biologic dosing intervals is more appropriate than discontinuation.

Characteristics and burden of disease in patients with radiographic versus non-radiographic axial spondyloarthritis in the ASRI cohort

BACKGROUND

Axial spondyloarthritis (axSpA) comprises patients with both radiographic and non-radiographic features. Previous studies have shown similar burden of disease between these two groups.

AIMS

The Ankylosing Spondylitis Registry of Ireland (ASRI) was formed with the objective to measure the burden of axial spondyloarthritis in the population and identify early predictors of a poor outcome. For this analysis, the ASRI database was used to compare the characteristics and burden of disease in patients with radiographic versus non-radiographic axial spondyloarthritis.

METHODS

Patients with radiographic axial spondyloarthritis (r-axSpA) were defined as those with X-ray evidence of sacroiliitis. Patients with non-radiographic axial spondyloarthritis (nr-axSpA) were defined as having MRI evidence of sacroiliitis but no X-ray evidence of sacroiliitis.

RESULTS

In total, 764 patients were included. Analysis of radiographic status showed 88.1% (n = 673) of patients with r-axSpA and 11.9% (n = 91) with nr-axSpA (Table 1). Patients with nr-axSpA were younger (41.3 vs. 46.6 years, p < 0.01), had shorter disease duration (14.8 vs. 20.2 years, p < 0.01) and had lower proportion of males (66.6% vs. 78.4%, p = 0.02) with lower frequency of HLA-B27 positivity (73.6% vs. 90.5%, p < 0.01). The nr-axSpA group had lower BASDAI (3.37 vs. 4.05, p = 0.01), BASFI (2.46 vs. 3.88, p < 0.01), BASMI (2.33 vs. 4.34, p < 0.01), ASQoL (5.2 vs. 6.67, p = 0.02) and HAQ scores (0.38 vs. 0.57, p < 0.01). There were no significant differences in the prevalence of extra-musculoskeletal manifestations or use of medications.

CONCLUSIONS

This study provides evidence to suggest that the burden of disease is less in patients with non-radiographic axial spondyloarthritis than radiographic axial spondyloarthritis.

Population pharmacokinetics and exposure-response analyses for efficacy and safety of upadacitinib in patients with axial spondyloarthritis

Upadacitinib is an orally administered, selective, Janus kinase inhibitor that is approved for several auto-immune conditions, such as axial spondyloarthritis, an inflammatory rheumatic disease that includes ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). The approvals of upadacitinib for the treatment of AS and nr-axSpA were based on the safety and efficacy data for upadacitinib 15 mg once-daily compared to placebo from the SELECT-AXIS 1 and SELECT-AXIS 2 studies. Population pharmacokinetic analyses based on data from 244 patients with axSpA showed that the pharmacokinetics of upadacitinib were comparable in subjects with AS and nr-axSpA. Exposure-response relationships were characterized for key efficacy and safety end points using data from 482 patients with axSpA. The exposure-response analyses for efficacy based on Assessment of SpondyloArthritis International Society (ASAS)20 and ASAS40 responses at week 14, showed a clear differentiation from placebo with no evidence of increased responses with increasing upadacitinib plasma exposures. There were no clear exposure-response trends observed for safety end points that included serious infections, herpes zoster, pneumonia, lymphopenia (grade ≥3), neutropenia (grade ≥3), or a greater than 2 g/dL decrease in hemoglobin from baseline through week 14. The exposure-response analyses for efficacy and safety presented here supported the favorable benefit-risk profile with the use of upadacitinib 15 mg once-daily for the treatment of axSpA.

Comparison of the ASAS Health Index in patients classified as radiographic axial spondyloarthritis (axSpA) or non-radiographic axSpA in the ASAS Health Index international validation study

OBJECTIVES

To determine if there were differences in the Assessment of SpondyloArthritis international Society Health Index (ASAS HI) scores between patients classified as radiographic axial spondyloarthritis (r-axSpA) and non-radiographic axSpA (nr-axSpA), and to identify factors associated with higher ASAS HI scores in both disease phenotypes.

METHODS

This study was an ancillary analysis of the ASAS HI international validation project performed in 23 countries. Patients were included if they were ≥18 years of age and diagnosed with axSpA. Univariable and multivariable analysis were performed to determine if ASAS HI scores differed between the axSpA phenotypes, and to identify other variables associated with ASAS HI scores. We also tested for potential interactions between the axSpA phenotype and significant variables identified through the multivariable regression.

RESULTS

A total of 976 patients were included, with 703 having r-axSpA and 273 nr-axSpA. Patients with r-axSpA reported higher (worse) ASAS HI scores compared with those with nr-axSpA (6.8 (4.4) vs 6.0 (4.0), p=0.02), but the axSpA phenotype was not associated with ASAS HI scores in the multivariable regression (β: -0.19, 95% CI: -0.56 to 0.19). Female gender, having worse physical function (Bath Ankylosing Spondylitis Functional Index), disease activity (Ankylosing Spondylitis Disease Activity Score) and anxiety and depressive symptoms (Hospital Anxiety and Depression Scale) were associated with higher ASAS HI scores. No interactions were found to be significant.

CONCLUSION

Overall health and functioning are similarly affected in patients with r-axSpA and nr-axSpA. Female patients, having worse physical function, disease activity, anxiety and depressive symptoms were independently associated with higher ASAS HI scores.

Bimekizumab treatment in patients with active axial spondyloarthritis: 52-week efficacy and safety from the randomised parallel phase 3 BE MOBILE 1 and BE MOBILE 2 studies

OBJECTIVES

Bimekizumab (BKZ), a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F in addition to IL-17A, has demonstrated superior efficacy versus placebo in patients with non-radiographic (nr-) and radiographic (r-) axial spondyloarthritis (axSpA) at Week 16. Here, the objective is to report the efficacy and safety of BKZ at Week 52.

METHODS

BE MOBILE 1 (nr-axSpA; NCT03928704) and BE MOBILE 2 (r-axSpA; NCT03928743) comprised a 16-week, double-blind, placebo-controlled period, then a 36-week maintenance period. From Week 16, all patients received subcutaneous BKZ 160 mg every 4 weeks.

RESULTS

Improvements versus placebo in Assessment of SpondyloArthritis International Society ≥40% response (primary endpoint), Ankylosing Spondylitis Disease Activity Score, high-sensitivity C-reactive protein levels and MRI inflammation of the sacroiliac joints/spine at Week 16 were sustained to Week 52 in BKZ-randomised patients. At Week 52, responses of patients switching from placebo to BKZ at Week 16 were comparable to BKZ-randomised patients. At Week 52, ≥1 treatment-emergent adverse events (TEAEs) were reported in 183 (75.0%) and 249 (75.5%) patients with nr-axSpA and r-axSpA, respectively. Serious TEAEs occurred in 9 (3.7%) patients with nr-axSpA and 20 (6.1%) patients with r-axSpA. Oral candidiasis was the most frequent fungal infection (nr-axSpA: 18 (7.4%); r-axSpA: 20 (6.1%)). Uveitis occurred in three (1.2%) and seven (2.1%) patients with nr-axSpA and r-axSpA, and inflammatory bowel disease in two (0.8%) and three (0.9%).

CONCLUSIONS

At Week 52, dual inhibition of IL-17A and IL-17F with BKZ resulted in sustained efficacy across the axSpA spectrum; the safety profile was consistent with the known safety of BKZ.

TRIAL REGISTRATION NUMBER

NCT03928704; NCT03928743.

A strategy towards disentangling treatment refractory from misdiagnosed axial Spondyloarthritis

Axial spondyloarthritis (axSpA) encompasses radiographic axial SpA (r-axSpA), formally designated as ankylosing spondylitis (AS) and non-radiographic axial SpA (nr-axSpA). The advent of MRI permitted the description of the "pre-radiographic" (nr-AxSpA) stage characterized by bone marrow oedema lesions, histologically an osteitis, not yet visible on X-rays. Most subjects with a diagnosis of nr-axSpA do not progress to r-axSpA and the risk of misdiagnosis of nr-axSpA is considerable because back pain related to malalignment, degenerative conditions or biomechanical stress including intense exercise may lead to positive MRI scans. Even when nr-axSpA or r-axSpA are accurately diagnosed only about 40-50% achieve the ASAS40 responses with licensed therapies. It is likely that spinal enthesitis/osteitis leading to structural damage and associated damage contributes to post inflammatory disc territory secondary pain responses. Things are complicated as the concept of refractory axSpA itself is not well defined since there is no gold standard test to capture the full burden of inflammatory disease and, in any event, MRI has not been systematically applied. Nevertheless, there is sufficient evidence to borrow from the refractory rheumatoid arthritis field to propose two types of refractory axial SpA- a persistent inflammatory refractory ax-SpA (PIRaxSpA) and non-inflammatory refractory ax-SpA (NIRaxSpA). Both axSpA refractoriness and misdiagnosis need careful considerations when evaluating treatment failure. The immunological basis for axSpA immunotherapeutics non-responses is still rudimentary beyond the knowledge of HLA-B27 positivity status, CRP elevation, and MRI bone oedema that represents osteitis being equated with responder status.

Probability of the 10-year Risk of Hip and Major Osteoporotic Fracture in Non-radiographic Axial Spondyloarthritis

BACKGROUND

Fracture risk in non-radiographic spondyloarthritis is underestimated. A reliable tool such as the Fracture Risk Assessment tool (FRAX) may assess this risk probability. This study aimed to assess the fracture risk by the FRAX score in patients with nr-axSpA and to determine factors associated with high fracture risk.

METHODS

We conducted a retrospective study of nr-axSpA patients meeting the Assessment of SpondyloArthritis International Society (ASAS) classification criteria for spondyloarthritis. All patients had Bone Mineral Density (BMD) by dual-energy X-ray absorptiometry (DEXA). The 10- year probability of major osteoporotic fracture (MOF) and hip fracture (HF) was calculated using the Fracture Risk Assessment Tool (FRAX).

RESULTS

Among 40 patients with nr-axSpA, 27 were women (67.5%). Their mean age was 43.7 ± 12.1 years. The mean disease duration was 3.15 ± 2.7 years. Eighteen patients (45%) had osteopenia, and 12 patients (30%) had osteoporosis. The median HF FRAX was 0% [0-1.2]. The median MOF FRAX was 0.5% [0.3-1.8]. MOF FRAX was positively correlated with age (p = 0.002), disease onset age (p = 0.006), disease duration (p = 0.024), and the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) (p < 0.0001), and negatively correlated with daily calcium intake (p < 0.0001). HF FRAX was positively correlated with mSASSS (p < 0.0001) and negatively correlated with daily calcium intake (p = 0.005).

CONCLUSION

Our study confirmed the frequency of bone loss during nr-axSpA and showed that osteoporotic risk fracture was related not only to traditional risk factors for osteoporosis but also to disease-related factors.

[Concept and understanding of non-radiographic axial spondyloarthritis]

Since the publication of the classification criteria for axial spondyloarthritis (axSpA) by Assessment of SpondyloArthritis international Society (ASAS), a new disease concept "non-radiographic axial spondyloarthritis (nr-axSpA)" has emerged. Some domestic experts in China have translated it as "radiologically negative" axSpA, but it can easily lead to misunderstandings literally, as not all patients with nr-axSpA are completely free from radiological abnormalities. This article briefly describes the evolution of the concept of axSpA, proposes to translate the term of nr-axSpA directly rather than "radiologically negative" axSpA, compares the differences and similarities between nr-axSpA and radiologically negative axSpA, delineates the relationship between nr-axSpA and early ankylosing spondylitis, and points out not all the patients who meet the ASAS classification criteria for nr-axSpA are genuine patients with axSpA, because of the relatively low specificity of the ASAS classification criteria. Five common scenarios easily leading to misdiagnosis of nr-axSpA are exampled to remind domestic colleagues.

Efficacy and safety of golimumab in patients with non-radiographic axial spondyloarthritis: a withdrawal and retreatment study (GO-BACK)

OBJECTIVES

The GO-BACK study was designed to evaluate the efficacy and safety of golimumab (GLM) treatment withdrawal in adults with non-radiographic axial spondyloarthritis (nr-axSpA) who demonstrate inactive disease during a 10-month open-label (OL) GLM run-in.

METHODS

Eligible participants received OL GLM in period 1. In period 2, participants who achieved inactive disease were randomized 1:1:1 to receive double-blind (DB) treatment with monthly placebo (PBO, treatment withdrawal) or continued GLM treatment given monthly (GLM QMT) or every 2 months (GLM Q2MT). Participants who did not have a disease flare continued DB treatment for ∼12 months. Participants with a disease flare discontinued DB treatment and resumed monthly OL GLM. Primary endpoint compared the proportion of participants without a disease flare in the continued GLM treatment groups (QMT or Q2MT) vs PBO in a multiplicity-controlled, step-down fashion. Safety follow-up continued for ∼3 months after last treatment.

RESULTS

A total of 188 patients, out of the 323 enrolled, were eligible for participation in period 2. Both GLM QMT and GLM Q2MT were superior to treatment withdrawal (PBO) in preventing disease flare (P < 0.001), with a treatment-difference vs PBO of 50.4% and 34.4% for the GLM QMT and GLM Q2MT groups, respectively. The time-to-first flare was significantly longer (log-rank P < 0.0001) with GLM treatment compared with PBO. Of 53 participants (in Q2MT or PBO) who had a confirmed disease flare, 51 (96.2%) attained a clinical response within 3 months of restarting OL GLM. Adverse events were consistent with the known GLM safety profile.

CONCLUSION

Among participants with active nr-axSpA who attained inactive disease after 10 months of GLM treatment, continued GLM treatment is well tolerated and provides superior protection against disease flares compared with GLM withdrawal. (EudraCT: 2015-004020-65, registered on 30 March 2022; NCT: 03253796, registered on 18 August 2017.).

Clinical Relevance of Axial Radiographic Damage in Axial Spondyloarthritis: Evaluation of Functional Consequences by an Objective Electronic Device

OBJECTIVE

Axial spondyloarthritis (axSpA) is associated with decreased function and mobility of patients as a result of inflammation and radiographic damage. The Epionics SPINE device (ES), an electronic device that objectively measures spinal mobility, including range of motion (RoM) and speed (ie, range of kinematics [RoK]) of movement, has been clinically validated in axSpA. We investigated the performance of the ES relative to radiographic damage in the axial skeleton of patients with axSpA.

METHODS

A total of 103 patients with axSpA, 31 with nonradiographic axSpA (nr-axSpA) and 72 with radiographic axSpA (r-axSpA), were consecutively examined. Conventional radiographs of the spine (including presence, number, and location of syndesmophytes) and the sacroiliac joints (SIJs; rated by the modified New York criteria) were analyzed with the ES. Function and mobility were assessed using analyses of covariance and Spearman correlation.

RESULTS

The number of syndesmophytes correlated positively with Bath Ankylosing Spondylitis Metrology Index scores (r 0.38, P = 0.02) and correlated negatively with chest expansion (r -0.39, P = 0.02) and ES measurements (-0.53 ≤ r ≤ -0.34, all P < 0.03), except for RoM and RoK regarding rotation and RoK for extension of the lumbar and thoracic spines. In the radiographic evaluation of the SIJs, the extent of damage correlated negatively with ES scores and metric measurements (-0.49 ≤ r ≤ -0.33, all P < 0.001). Patients with r-axSpA, as compared to those with nr-axSpA, showed significantly worse ES scores for RoM, RoK, and chest expansion.

CONCLUSION

The ES scores, in accordance with mobility measurements, correlated well with the presence and extent of radiographic damage in the spine and the SIJs. As expected, patients with r-axSpA had more severe impairments than those with nr-axSpA.

Clinical significance of possible HLA biomarkers in axial spondyloarthritis beyond HLA-B27 positivity

The aim of this study is to compare four forms of axial spondyloarthritis (axSpA): non-radiographic axial spondyloarthritis (nr-axSpA), ankylosing spondylitis (AS), non-radiographic axial psoriatic arthritis (nr-axPsA) and radiographic axial psoriatic arthritis (r-axPsA). In a cross-sectional retrospective study, gender difference, human leukocyte antigen (HLA) typing, laboratory C-reactive protein (CRP) and erythrocyte sedimentation (SE) values, and radiographic and magnetic resonance scans were analyzed. One hundred and thirty-seven patients were included in the study: 45 AS, 51 nr-axSpA, 32 r-axPsA and 9 nr-axPsA; 74 women and 63 men. Most of the gender, laboratory and radiological findings confirmed the results of previously conducted studies about each group of the investigated axSpA. The key findings of our study are the newly detected findings of HLA typing beyond HLA-27 positivity: HLA-DR16 in AS, HLA-DR11 in nr-axSpA, HLA-B13, HLA-B57, HLA-Cw12 and HLA-DR7 in r-axPsA, and HLA-B18 in nr-axPsA. Our study also confirmed some of the results of previously conducted studies on predominant genes of HLA typing in axSpA: HLA-B27 in AS, HLA-B39 and HLA-Cw6 in r-axPsA, and HLA-Cw7 in nr-axPsA. Important conclusions about the nr-axPsA group cannot be drawn because of the very small number of subjects included in this group of axSpA. Our results suggest that the newly detected HLA typing findings beyond HLA-B27 positivity could be possible biomarkers of early detection of axSpA, but further studies on larger samples are needed.

A comparison of the clinical characteristics and quality of life of male and female patients with non-radiographic axial spondyloarthritis

OBJECTIVE

The aim of this study was to compare the clinical characteristics and quality of life of male and female patients with non-radiographic axial spondyloarthritis (nraxSpA) to determine the differences and similarities.

PATIENTS AND METHODS

The study included 100 patients, comprising 50 males and 50 females, aged 18-65 years, who presented at the Rheumatology Clinic and were diagnosed with nr-axSpA according to the Assessment of Spondyloarthritis International Society (ASAS) criteria. The data of patient age, gender, body mass index, disease duration, and drugs used were recorded. Disease activity was evaluated with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), mobility with the Bath Ankylosing Spondylitis Metrology Index (BASMI), functional status with the Bath Ankylosing Spondylitis Functional Index (BASFI), enthesitis with the Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), and quality of life with the Ankylosing Spondylitis Quality of Life (ASQoL). The patients with nr- axSpA were separated into groups as male and female, and the demographic and clinical data were compared.

RESULTS

The mean age of female patients was determined to be statistically significantly higher than that of the male patients (39.04 ± 0.70 vs. 34.28 ± 9.26 years, p:0.014). A statistically greater number of male patients were smokers (p:0.007). The disease duration and time since diagnosis were determined to be significantly longer in females than in males (p:0.029, p:0.004). Peripheral arthritis was determined at a significantly higher rate in females (p < 0.001). The MASES score was 2.66 ± 3.46 in females and 0.52 ± 1.03 in males, and the difference was statistically significant (p < 0.001). The BASDAI score was significantly higher in females (3.74 ± 2.35) than in males (2.88 ± 1.95) (p:0.05). No statistically significant difference was determined between the two groups in respect of BASFI, BASMI, ASQoL, and other parameters.

CONCLUSION

The results showed older age, longer disease duration and time to diagnosis, higher rates of peripheral arthritis, and higher MASES and BASDAI scores in the female patients. Thus, there are some differences between male and female patients. Further studies should determine what kind of changes these differences will make in the clinical status, follow-up and treatment of patients.

A mixed methods study to uncover impediments to accurate diagnosis of nonradiographic axial spondyloarthritis in the USA

INTRODUCTION/OBJECTIVES

Delayed diagnosis of axial spondyloarthritis (axSpA) is well documented; little is known about the diagnostic journey and impediments for US patients with nonradiographic axSpA (nr-axSpA). It is hypothesized that impediments are varied and exist at both the healthcare provider (HCP) and patient levels. This study aims to understand patient experiences and contributors to delayed nr-axSpA diagnosis in the USA.

METHOD

Interviews of adults with rheumatologist-diagnosed nr-axSpA, recruited through Spondylitis Association of America outreach and patient panels, and of rheumatologists, explored the diagnostic journey and diagnostic barriers. Emerging themes were further explored in an online patient survey. A multiple logistic regression analysis evaluated the main outcome variable, factors affecting time to nr-axSpA diagnosis.

RESULTS

Interviews were conducted with 25 patients and 16 rheumatologists. Survey responses from 186 eligible patients revealed median time from symptom onset to diagnosis of nr-axSpA was 3.25 years. Delayed diagnosis was significantly more likely for women and people in rural areas. Most patients consulted ≥4 different types of HCPs before a rheumatologist and ≥2 rheumatologists before diagnosis. Impediments to timely diagnosis included insidious chronic pain; episodic symptom patterns attributed to activity; symptoms other than chronic lumbosacral back pain requiring medical consultation; and unfamiliarity with and misperceptions about nr-axSpA among HCPs, radiologists, and rheumatologists.

CONCLUSIONS

Delayed nr-axSpA diagnosis is common and reflects HCP knowledge gaps and frequent patient presentation with dominant nonaxial symptoms. Targeted HCP education, research into early disease patterns, and interventions sensitive to the broader spectrum of nr-axSpA manifestations are needed to improve timely diagnosis. Key Points • Patients with nr-axSpA often see multiple types of HCPs, and multiple rheumatologists, before receiving a diagnosis. • Both patients and HCPs are unfamiliar with nr-axSpA and its symptoms, lacking understanding that nr-axSpA can occur in young people, females, and those presenting with normal x-rays. • Disease recognition by nonrheumatology HCPs is key for early referral. • Education on cardinal features, epidemiology, burden, and benefits of timely nr-axSpA diagnosis is warranted for HCPs who commonly manage back pain.

Advances in pharmacotherapies for axial spondyloarthritis

INTRODUCTION

Axial spondyloarthritis (axSpA) refers to an inflammatory rheumatic disease that mainly affects the axial skeleton and leads to progressive radiographic changes of the sacroiliac joints and spine. axSpA is currently subdivided into the radiographic (r-axSpA) and non-radiographic (nr-axSpA) form. Both forms are associated with musculoskeletal pain, restriction of spinal mobility, specific extra-musculoskeletal manifestations, and overall, altered quality of life. The therapeutic management of axSpA is currently well standardized.

AREAS COVERED

We reviewed available literature (by using PubMed search) on non-pharmacological and pharmacological treatment options that may be used in axSpA, including r-axSpA and nr-axSpA, as well as the role of non-steroidal anti-inflammatory drugs (NSAIDs), biological agents including TNFalpha (TNFi) and IL-17 (IL-17i) inhibitors. New treatment options such as Janus kinase inhibitors are also reviewed.

EXPERT OPINION

NSAIDs remain the mainstay of initial therapy, and subsequently, biological agents (TNFi and IL-17i) may be envisaged. Four TNFi are licensed for the treatment of both r-axSpA and nr-axSpA, while IL-17i are approved in each indication. The choice between a TNFi and an IL-17i is mainly guided by the presence of extra-articular manifestations. JAKi were more recently introduced for the treatment of r-axSpA, but their use is restricted to specific patients with a safe cardiovascular profile.

Disease course of non-radiographic axial spondyloarthritis: Data from a long-term retrospective observational cohort

BACKGROUND

Disease course of non-radiographic axial spondyloarthritis (axSpA) has been extensively studied in non-Asian population; however, there are limited data in Asian population. This study aimed to evaluate the long-term disease course of non-radiographic axSpA in Asian patients and identify factors associated with progression to radiographic axSpA.

METHODS

In this retrospective observational cohort study, 56 Korean patients newly diagnosed with non-radiographic axSpA between 2006 and 2015 were included. All patients fulfilled the Assessment of SpondyloArthritis international Society classification criteria for axSpA, and did not fulfil the radiological criterion of the 1984 modified New York criteria. Disease course was assessed by the rate of progression to radiographic axSpA. Factors associated with the risk of progression to radiographic axSpA were assessed using multivariable Cox proportional hazard regression analysis.

RESULTS

The mean age at baseline was 31.4±13.3 years, and 37 (66.1%) patients were men. Over a mean observation period of 8.4±3.7 years, 28 (50.0%) patients progressed to radiographic axSpA. In multivariable Cox proportional hazard regression analysis, the presence of syndesmophytes at diagnosis (adjusted hazard ratio [HR]: 4.50, 95% confidence interval [CI]: 1.54-13.15, p = 0.006) and active sacroiliitis on magnetic resonance imaging (MRI) at diagnosis (adjusted HR: 5.88, 95% CI: 2.05-16.82, p = 0.001) were significantly associated with a higher risk of progression to radiographic axSpA, whereas longer exposure to tumor necrosis factor inhibitors (TNFis) was significantly associated with a lower risk of progression to radiographic axSpA (adjusted HR: 0.89, 95% CI: 0.80-0.98, p = 0.022).

CONCLUSION

During long-term follow-up, a substantial proportion of Asian patients with non-radiographic axSpA progressed to radiographic axSpA. The presence of syndesmophytes and active sacroiliitis on MRI at the time of non-radiographic axSpA diagnosis were associated with a higher risk of progression to radiographic axSpA, while longer exposure to TNFis was associated with a lower risk of progression to radiographic axSpA.

Efficacy and safety of bimekizumab in axial spondyloarthritis: results of two parallel phase 3 randomised controlled trials

OBJECTIVES

Axial spondyloarthritis (axSpA) is a complex disease with diverse manifestations, for which new treatment options are warranted. BE MOBILE 1 (non-radiographic (nr)-axSpA) and BE MOBILE 2 (radiographic axSpA (r-axSpA)) are double-blind, phase 3 trials designed to evaluate efficacy and safety of bimekizumab, a novel dual interleukin (IL)-17A and IL-17F inhibitor, across the axSpA spectrum.

METHODS

In parallel 52-week trials, patients with active disease were randomised 1:1 (nr-axSpA) or 2:1 (r-axSpA) to bimekizumab 160 mg every 4 weeks:placebo. From week 16, all patients received bimekizumab 160 mg every 4 weeks. Primary (Assessment of SpondyloArthritis international Society ≥40% improvement (ASAS40)) and secondary endpoints were assessed at week 16. Here, efficacy and treatment-emergent adverse events (TEAEs) are reported up to week 24.

RESULTS

254 patients with nr-axSpA and 332 with r-axSpA were randomised. At week 16, primary (ASAS40, nr-axSpA: 47.7% bimekizumab vs 21.4% placebo; r-axSpA: 44.8% vs 22.5%; p<0.001) and all ranked secondary endpoints were met in both trials. ASAS40 responses were similar across TNFi-naïve and TNFi-inadequate responder patients. Improvements were observed in Ankylosing Spondylitis Disease Activity Score (ASDAS) states and objective measures of inflammation, including high-sensitivity C-reactive protein (hs-CRP) and MRI of the sacroiliac joints and spine. Most frequent TEAEs with bimekizumab (>3%) included nasopharyngitis, upper respiratory tract infection, pharyngitis, diarrhoea, headache and oral candidiasis. More fungal infections (all localised) were observed with bimekizumab vs placebo; no major adverse cardiovascular events (MACE) or active tuberculosis were reported. Incidence of uveitis and adjudicated inflammatory bowel disease was low.

CONCLUSIONS

Dual inhibition of IL-17A and IL-17F with bimekizumab resulted in significant and rapid improvements in efficacy outcomes vs placebo and was well tolerated in patients with nr-axSpA and r-axSpA.

Challenges in non-radiographic axial spondyloarthritis

Non-radiographic axial spondyloarthritis (nr-axSpA) is part of the spectrum or continuum of axSpA and is characterized by the absence of definite structural damage in the sacroiliac joints. The introduction of the concept of axSpA with two - non-radiographic and radiographic - stages stimulated activities related to the improvement of early diagnosis and treatment of this disease, but also opened a number of controversial topics in the field. In this article, we are discussing several challenges related to the concept of nr-axSpA, the diagnosis, and the treatment in the historical context and in the light of the recent data.

Effects of ixekizumab treatment on structural changes in the sacroiliac joint: MRI assessments at 16 weeks in patients with non-radiographic axial spondyloarthritis

BACKGROUND

There is limited understanding regarding the inhibition of structural damage in the sacroiliac joint of patients with non-radiographic axial spondyloarthritis. This study evaluated the effect of the interleukin-17A inhibitor ixekizumab versus placebo on structural lesions in the sacroiliac joints as assessed by MRI at week 16 in patients with non-radiographic axial spondyloarthritis from the COAST-X study.

METHODS

COAST-X was a 52-week, randomised, double-blind, placebo-controlled, parallel-group study done at 107 sites in 15 countries in Europe, Asia, North America, and South America. Eligible participants were adults (aged ≥18 years) with active axial spondyloarthritis without definite radiographic sacroiliitis (non-radiographic axial spondyloarthritis), objective signs of inflammation (via MRI or C-reactive protein), and an inadequate response or intolerance to non-steroidal anti-inflammatory drugs. Patients were randomly allocated to placebo or double-blind ixekizumab 80 mg every 4 weeks (Q4W) or 2 weeks (Q2W), with an 80 mg or 160 mg starting dose. We report a post-hoc analysis of 266 patients with available MRI scans from baseline and week 16. MRI scans were scored using the Spondyloarthritis Research Consortium of Canada (SPARCC) sacroiliac joint structural score (SSS) method independently by two masked readers. Treatment comparisons used analysis of covariance based on observed cases. Correlations were evaluated among changes in SPARCC SSS for erosion, fat lesions, and backfill, and between changes in SPARCC SSS and sacroiliac joint inflammation scores and clinical measures. COAST-X was registered with ClinicalTrials.gov, NCT02757352.

FINDINGS

Between Aug 2, 2016, and Jan 29, 2018, 303 patients were enrolled to the COAST-X study. 290 (96%) of 303 participants completed the week 16 visit (95 in the ixekizumab Q4W group, 98 in the ixekizumab Q2W group, and 97 in the placebo group), and MRI scans were available for 266 patients at baseline and week 16 (85 in the ixekizumab Q4W group, 91 in the ixekizumab Q2W group, and 90 in the placebo group). Changes from baseline to week 16 in mean SPARCC SSS for erosion were -0·39 for ixekizumab Q4W (p=0·003 vs placebo), -0·40 for ixekizumab Q2W (p=0·002), and 0·16 for placebo; for fat lesions: 0·16 for ixekizumab Q4W (p=0·013), 0·10 for ixekizumab Q2W (p=0·067), and -0·04 for placebo; and for backfill: 0·21 for ixekizumab Q4W (p=0·011), 0·22 for ixekizumab Q2W (p=0·006), and -0·10 for placebo. Ankylosis did not change. Effects of ixekizumab versus placebo on structural changes were most pronounced in patients with baseline inflammation in the sacroiliac joints. Changes from baseline at week 16 in erosion, fat lesions, and backfill were correlated.

INTERPRETATION

Although the clinical relevance is not yet clear, patients with non-radiographic axial spondyloarthritis receiving ixekizumab had significant reductions in erosions and increases in fat lesions and backfill in the sacroiliac joints versus placebo at week 16, suggesting an early repair process with ixekizumab treatment.

FUNDING

Eli Lilly and Company.

Upadacitinib for the treatment of active non-radiographic axial spondyloarthritis (SELECT-AXIS 2): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Upadacitinib, a Janus kinase inhibitor, has been shown to be effective in patients with ankylosing spondylitis. We aimed to assess the efficacy and safety of upadacitinib in non-radiographic axial spondyloarthritis.

METHODS

The SELECT-AXIS 2 non-radiographic axial spondyloarthritis study was a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 113 sites across 23 countries (Argentina, Australia, Belgium, Brazil, Bulgaria, Canada, China, Czech Republic, France, Germany, Hungary, Israel, Japan, Mexico, Poland, Russia, Slovakia, South Korea, Spain, Taiwan, Turkey, Ukraine, and the USA). Eligible adults had active non-radiographic axial spondyloarthritis, with objective signs of inflammation based on MRI or elevated C-reactive protein and an inadequate response to non-steroidal anti-inflammatory drugs. Patients were randomly assigned (1:1) to receive oral upadacitinib 15 mg once daily or placebo using interactive response technology. Random treatment assignment was stratified by MRI inflammation in the sacroiliac joints and screening high-sensitivity C-reactive protein status (MRI-positive and C-reactive protein-positive, MRI-positive and C-reactive protein-negative, and MRI-negative and C-reactive protein-positive) and previous exposure to biologic disease-modifying antirheumatic drugs (yes vs no). Treatment assignment was masked from patients, investigators, study site personnel, and the study sponsor. The primary endpoint was the proportion of patients with an Assessment of SpondyloArthritis international Society 40 (ASAS40) response at week 14. Analyses were performed on the full analysis set of patients, who underwent random allocation and received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT04169373.

FINDINGS

Between Nov 26, 2019, and May 20, 2021, 314 patients with active non-radiographic axial spondyloarthritis were enrolled into the study, and 313 received study drug (156 in the upadacitinib group and 157 in the placebo group); 295 (94%) patients (145 in the upadacitinib group and 150 in the placebo group) received treatment for the full 14 weeks. A significantly higher ASAS40 response rate was achieved with upadacitinib compared with placebo at week 14 (70 [45%] of 156 patients vs 35 [23%] of 157 patients; p<0·0001; treatment difference 22%, 95% CI 12-32). The rate of adverse events up to week 14 was similar in the upadacitinib group (75 [48%] of 156 patients) and placebo group (72 [46%] of 157 patients). Serious adverse events and adverse events leading to discontinuation of study drug occurred in four (3%) of 156 patients in the upadacitinib group and two (1%) of 157 patients in the placebo group. Few patients had serious infections or herpes zoster in either treatment group (each event occurred in two [1%] of 156 patients in the upadacitinib group and one [1%] of 157 patients in the placebo group). Five (3%) of 156 patients in the upadacitinib group had neutropenia; no events of neutropenia occurred in the placebo group. No opportunistic infections, malignancies, major adverse cardiovascular events, venous thromboembolic events, or deaths were reported with upadacitinib treatment.

INTERPRETATION

Upadacitinib significantly improved the signs and symptoms of non-radiographic axial spondyloarthritis compared with placebo at week 14. These findings support the potential of upadacitinib as a new therapeutic option in patients with active non-radiographic axial spondyloarthritis.

FUNDING

AbbVie.

Nonradiographic axial spondyloarthritis: expanding the spectrum of an old disease: A narrative review

Nonradiographic axial spondyloarthritis (nr-axSpA) represents a distinct phenotype within the spectrum of axial spondyloarthritis (axSpA), which is characterized by a range of clinical manifestations. Despite a high disease burden that is comparable to ankylosing spondylitis (also known as radiographic axSpA), there is an unmet need to recognize and effectively manage patients with active nr-axSpA.A targeted literature search was conducted in OVID (MEDLINE and Embase databases) to identify articles on nr-axSpA, including its definition, demographics, epidemiology, burden, diagnosis, clinical presentation, and treatment guidelines.The lack of adequate epidemiological data and incomplete understanding of nr-axSpA among rheumatologists and nonrheumatologists contributes to delayed referrals and diagnosis. This delay results in a substantial burden on patients, physically and psychologically, and the healthcare system. Targeted therapies, such as biologics, including inhibitors of tumor necrosis factor or interleukin-17A, have been approved and utilized for the management of nr-axSpA, and other novel therapeutics with different mechanisms of action are in development. Raising awareness among US internists regarding the prevalence of nr-axSpA, disease burden, clinical presentation, diagnostic tools, and available treatments is important for improved disease management.Future clinical investigations focusing on the development of markers that aid early diagnosis and predict treatment response may also improve the management of nr-axSpA. This review provides an overview of nr-axSpA with the aim of raising awareness of the disease among US internists, with an overarching goal to contribute toward the improved recognition and timely referral of these patients to rheumatologists for diagnosis and management.