Disease modification in axial spondyloarthritis - still a controversy?

PURPOSE OF REVIEW

This review evaluates recent advancements in disease-modifying therapies for axial spondyloarthritis (axSpA).

RECENT FINDINGS

A recent study could not demonstrate an additional effect of NSAID therapy on golimumab [Tumor Necrosis Factor-α inhibitor (TNFi)] on structural progression; however, this might be due to the fact that the study was underpowered. While DMARDs have shown promise in suppressing inflammation, their impact on structural progression remains uncertain. A well powered trial showed no difference in spinal progression between secukinumab [Interleukin17A inhibitor (IL17Ai)] and adalimumab-biosimilar (TNFi). Preliminary data on Janus kinase inhibitors (JAKi) focus on MRI findings but lack evidence on radiographic spinal progression. While some studies suggest promising outcomes, others reveal limitations and inconclusive findings.

SUMMARY

Recent studies explore the effectiveness of NSAIDs, biological disease-modifying antirheumatic drugs like TNFi and IL-17i, as well as JAK inhibitors in axSpA. Conflicting evidence surrounds these therapies' ability to impede structural progression, with challenges in study design and interpretation. Moreover, changes in demographics and treatment methods underscore the importance of examining trends over time when assessing disease outcomes. Ultimately, ongoing research could benefit from new imaging tools when evaluating therapeutic strategies for modifying disease progression in axSpA.

Effect of Secukinumab Versus Adalimumab Biosimilar on Radiographic Progression in Patients With Radiographic Axial Spondyloarthritis: Results From a Head-to-Head Randomized Phase IIIb Study

OBJECTIVE

Spinal radiographic progression is an important outcome in radiographic axial spondyloarthritis (SpA). The objective of the phase IIIb SURPASS study was to compare spinal radiographic progression in patients with radiographic axial SpA treated with secukinumab (interleukin-17A inhibitor) versus adalimumab biosimilar (Sandoz adalimumab [SDZ-ADL]; tumor necrosis factor inhibitor).

METHODS

Biologic-naive patients with active radiographic axial SpA, at high risk of radiographic progression (high-sensitivity C-reactive protein [hsCRP] ≥5 mg/L and/or ≥1 syndesmophyte[s] on spinal radiographs), were randomized (1:1:1) to secukinumab (150/300 mg) or SDZ-ADL (40 mg). The proportion of patients with no radiographic progression (change from baseline [CFB] in modified Stoke Ankylosing Spondylitis Spinal Score [mSASSS] ≤0.5) on secukinumab versus SDZ-ADL at week 104 (primary endpoint), mean CFB-mSASSS, proportion of patients with ≥1 syndesmophyte(s) at baseline with no new syndesmophyte(s), and safety were evaluated.

RESULTS

Overall, 859 patients (78.5% male, mSASSS 16.6, Bath Ankylosing Spondylitis Disease Activity Index 7.1, hsCRP 20.4 mg/L, and 73.0% with ≥1 syndesmophyte[s]) received secukinumab 150 mg (n = 287), secukinumab 300 mg (n = 286), or SDZ-ADL (n = 286). At week 104, the proportion of patients with no radiographic progression was 66.1%, 66.9%, and 65.6% (P = not significant, both secukinumab doses) and mean CFB-mSASSS was 0.54, 0.55, and 0.72 in secukinumab 150 mg, secukinumab 300 mg, and SDZ-ADL arms, respectively. Overall, 56.9%, 53.8%, and 53.3% of patients on secukinumab 150 mg, secukinumab 300 mg, and SDZ-ADL, respectively, with ≥1 syndesmophyte(s) at baseline did not develop new syndesmophyte(s) by week 104. There were no unexpected safety findings.

CONCLUSION

Spinal radiographic progression over two years was low with no significant difference between secukinumab and SDZ-ADL arms. The safety of both treatments was consistent with previous reports.

The Role of Early Treatment in the Management of Axial Spondyloarthritis: Challenges and Opportunities

Axial spondyloarthritis (axSpA) is a chronic, inflammatory rheumatic disease that primarily affects the axial skeleton, often inflicting severe pain, diminished mobility, and a compromised quality of life. The advent of Assessment of SpondyloArthritis international Society (ASAS) classification criteria for spondyloarthritis (SpA) have enabled the classification of patients with axSpA in the non-radiographic stage but poorly perform if mistakenly used for diagnostic purposes. Despite notable progress in early diagnosis facilitated by referral strategies and extensive magnetic resonance imaging (MRI) utilization, diagnostic delays persist as a concerning issue. This underscores the urgency to narrow the diagnostic gap and highlights the critical role of early diagnosis in mitigating the long-term structural damage associated with this condition. Research into the impact of non-steroidal anti-inflammatory drugs (NSAIDs) and biologic disease-modifying antirheumatic drugs (bDMARDs) on inflammatory symptoms and radiographic progression has been extensive. A compelling body of evidence suggests that early intervention leads to superior disease outcomes. However, most of these studies have centered on patients with established diseases rather than those in the early stages. Consequently, findings from studies on early pharmacological intervention remain inconclusive, and the potential for modifying the disease trajectory is still debatable. Without precise data from clinical trials, insights from basic science regarding the pathogenic mechanisms might point toward potential targets that warrant early intervention in the disease process. This review underscores the urgency of early diagnosis and intervention in axSpA, highlighting ongoing research gaps and the need for further exploration to improve patient outcomes.

Osteoimmunology of Spondyloarthritis

The mechanisms underlying the development of bone damage in the context of spondyloarthritis (SpA) are not completely understood. To date, a considerable amount of evidence indicates that several developmental pathways are crucially involved in osteoimmunology. The present review explores the biological mechanisms underlying the relationship between inflammatory dysregulation, structural progression, and osteoporosis in this diverse family of conditions. We summarize the current knowledge of bone biology and balance and the foundations of bone regulation, including bone morphogenetic protein, the Wnt pathway, and Hedgehog signaling, as well as the role of cytokines in the development of bone damage in SpA. Other areas surveyed include the pathobiology of bone damage and systemic bone loss (osteoporosis) in SpA and the effects of pharmacological treatment on focal bone damage. Lastly, we present data relative to a survey of bone metabolic assessment in SpA from Italian bone specialist rheumatology centers. The results confirm that most of the attention to bone health is given to postmenopausal subjects and that the aspect of metabolic bone health may still be underrepresented. In our opinion, it may be the time for a call to action to increase the interest in and focus on the diagnosis and management of SpA.

Disease activity-guided tapering of biologics in patients with inflammatory arthritis: a pragmatic, randomized, open-label, equivalence trial

OBJECTIVE

To evaluate whether disease activity-guided tapering of biologics compared to continuation as usual care enables a substantial dose reduction while disease activity remains equivalent.

METHOD

In this pragmatic, randomized, open-label, equivalence trial, adults with rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis in low disease activity on stable-dose biologics for ≥ 12 months were randomized 2:1 into either the tapering group, i.e. disease activity-guided prolongation of the biologic dosing interval until flare or withdrawal, or the control group, i.e. maintaince of baseline biologics with a possible small interval increase at the patients request. The co-primary outcome in the intention-to-treat population was met if superiority in ≥ 50% biologic reduction at 18 months was demonstrated and disease activity was equivalent (equivalence margins ± 0.5).

RESULTS

Ninety-five patients were randomized to tapering and 47 to control, of whom 37% (35/95) versus 2% (1/47) achieved ≥ 50% biologic reduction at 18 months. The risk difference was statistically significant [35%, 95% confidence interval (CI) 24%-45%], while disease activity remained equivalent [mean difference 0.05, 95% CI -0.12-0.29]. A statistically significant flare risk was observed [tapering 41% (39/95) vs control 21% (10/47), risk difference 20%, 95% CI 4%-35%]; but, only 1% (1/95) and 6% (3/47) had persistent flare and needed to switch to another biological drug.

CONCLUSIONS

Disease activity-guided tapering of biologics in patients with inflammatory arthritis enabled one-third to achieve ≥ 50% biologic reduction, while disease activity between groups remained equivalent. Flares were more frequent in the tapering group but were managed with rescue therapy.

Axial involvement in enthesitis-related arthritis: results from a single-center cohort

BACKGROUND

Axial involvement in children with enthesitis-related arthritis (ERA) has characteristics that differ from those of peripheral involvement. This study characterized their clinical characteristics and treatment.

METHODS

Patients with ERA at the Children's Hospital of Nanjing Medical University between January 2018 and December 2020 were included. The ERA cohort was divided into two based on the presence or absence of axial joint involvement. Demographic characteristics, clinical features, and treatments were described and compared.

RESULTS

In total, 105 children with ERA were enrolled (axial ERA, n = 57; peripheral ERA, n = 48). The age at disease onset of the axial group tended to be higher (11.93 ± 1.72 vs. 11.09 ± 1.91 years) and the diagnosis delay was bigger in patients with axial ERA (10.26 ± 11.66 months vs. 5.13 ± 7.92 months). The inflammatory marker levels were significantly higher in patients with axial. There were no differences in HLA-B27 positivity between the groups (34 [59.65%] vs. 28 [58.33%], P > 0.05). Hip involvement was more frequent in the axial group (52.63% vs 27.08%; X² = 7.033). A total of 38 (66.67%) and 10 (20.83%) patients with axial and peripheral ERA, respectively, were treated with biological disease-modifying anti-rheumatic drugs (DMARDs) at diagnosis. The administration of biologics increased gradually in the axial ERA group, peaking at 18 months and decreasing thereafter, whereas that in the peripheral ERA group peaked at 6 months and began to decline thereafter.

CONCLUSIONS

Axial ERA is a persistent active disease and requires a more aggressive treatment. Classification and early recognition of axial involvement may help with timely diagnosis and appropriate management.

Treat-to-target dose reduction and withdrawal strategy of TNF inhibitors in psoriatic arthritis and axial spondyloarthritis: a randomised controlled non-inferiority trial

OBJECTIVES

Tumour necrosis factor inhibitors (TNFi) are effective in psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), but are associated with a small (0.6%) increase in serious infection risk, patient burden due to need for self-injection and high costs. Treat-to-target (T2T) tapering might ameliorate these drawbacks, but high-quality evidence on T2T tapering strategies is lacking in PsA and axSpA.

METHODS

We performed a pragmatic open-label, monocentre, randomised controlled non-inferiority (NI) trial on T2T tapering of TNFi. Patients with PsA and axSpA using a TNFi with ≥6 months stable low disease activity (LDA) were included. Patients were randomised 2:1 to disease activity-guided T2T with or without tapering until withdrawal and followed-up to 12 months. Primary endpoint was the difference in proportion of patients having LDA at 12 months between groups, compared with a prespecified NI margin of 20%, estimated using a Bayesian prior.

RESULTS

122 patients (64 PsA and 58 axSpA) were randomised to a T2T strategy with (N=81) or without tapering (N=41). The proportion of patients in LDA at 12 months was 69% for the tapering and 73% for the no-tapering group: adjusted difference 5% (Bayesian 95% credible interval: -10% to 19%) which confirms NI considering the NI margin of 20%. The mean percentage of daily defined dose was 53% for the tapering and 91% for the no-tapering group at month 12.

CONCLUSIONS

A T2T TNFi strategy with tapering attempt is non-inferior to a T2T strategy without tapering with regard to the proportion of patients still in LDA at 12 months, and results in a substantial reduction of TNFi use.

TRIAL REGISTRATION NUMBER

NL 6771.

Effects of targeted therapies on bone in rheumatic and musculoskeletal diseases

Generalized bone loss (osteoporosis) and fragility fractures can occur in rheumatic and musculoskeletal diseases including rheumatoid arthritis and spondyloarthritis (SpA; including ankylosing spondylitis and psoriatic arthritis). In addition, rheumatoid arthritis can involve localized, periarticular bone erosion and, in SpA, local (pathological) bone formation can occur. The RANK-RANKL-osteoprotegerin axis and the Wnt-β-catenin signalling pathway (along with its inhibitors sclerostin and Dickkopf 1) have been implicated in inflammatory bone loss and formation, respectively. Targeted therapies including biologic DMARDs and Janus kinase (JAK) inhibitors can stabilize bone turnover and inhibit radiographic joint damage, and potentially also prevent generalized bone loss. Targeted therapies interfere at various points in the mechanisms of local and generalized bone changes in systemic rheumatic diseases, and they effect biomarkers of bone resorption and formation, bone mass and risk of fragility fractures. Studies on the effects of targeted therapies on rates of fragility fracture are scarce. The efficacy of biologic DMARDs for arresting bone formation in axial SpA is debated. Improved understanding of the most relevant therapeutic targets and identification of important targeted therapies could lead to the preservation of bone in inflammatory rheumatic and musculoskeletal diseases.

Sustained low disease activity measured by ASDAS slow radiographic spinal progression in axial spondyloarthritis patients treated with TNF-inhibitors: data from REGISPONSERBIO

Background

To evaluate the influence of the disease activity on radiographic progression in axial spondyloarthritis (axSpA) patients treated with TNF inhibitors (TNFi).

Methods

The study included 101 axSpA patients from the Spanish Register of Biological Therapy in Spondyloarthritides (REGISPONSERBIO), which had clinical data and radiographic assessment available. Patients were classified into 2 groups based on the duration of TNFi treatment at baseline: (i) long-term treatment (≥4 years) and (ii) no long-term treatment (< 4 years). Radiographs were scored by two readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) with known chronology. Disease activity differences between patients’ groups at each time point were assessed using a linear mixed-effect model.

Results

Radiographic progression was defined as an increase in ≥2 mSASSS units. At inclusion, approximately half of the patients (45.5%) were receiving long-term treatment with TNFi (≥4 years). In this group of subjects, a significant difference in averaged Ankylosing Spondylitis disease Activity Score (ASDAS) across follow-up was found between progressors and non-progressors (2.33 vs 1.76, p=0.027, respectively). In patients not under long-term TNFi treatment (54.5%) though, no significant ASDAS differences were observed between progressors and non-progressors until the third year of follow-up. Furthermore, no significant differences were found in progression status, when disease activity was measured by Bath Ankylosing spondylitis Disease Activity Index (BASDAI) and C reactive protein (CRP).

Conclusions

Patients on long-term TNFi treatment with a mean sustained low disease activity measures by ASDAS presented lower radiographic progression than those with active disease.

Dual Blockade of TNF and IL-17A Inhibits Inflammation and Structural Damage in a Rat Model of Spondyloarthritis

The tumor necrosis factor (TNF) and IL-23/IL-17 axes are the main therapeutic targets in spondyloarthritis. Despite the clinical efficacy of blocking either pathway, monotherapy does not induce remission in all patients and its effect on new bone formation remains unclear. We aimed to study the effect of TNF and IL-17A dual inhibition on clinical disease and structural damage using the HLA-B27/human β2-microglobulin transgenic rat model of SpA. Immunized rats were randomized according to arthritis severity, 1 week after arthritis incidence reached 50%, to be treated twice weekly for a period of 5 weeks with either a dual blockade therapy of an anti-TNF antibody and an anti-IL-17A antibody, a single therapy of either antibody, or PBS as vehicle control. Treatment-blinded observers assessed inflammation and structural damage clinically, histologically and by micro-CT imaging. Both single therapies as well as TNF and IL-17A dual blockade therapy reduced clinical spondylitis and peripheral arthritis effectively and similarly. Clinical improvement was confirmed for all treatments by a reduction of histological inflammation and pannus formation (p < 0.05) at the caudal spine. All treatments showed an improvement of structural changes at the axial and peripheral joints on micro-CT imaging, with a significant decrease for roughness (p < 0.05), which reflects both erosion and new bone formation, at the level of the caudal spine. The effect of dual blockade therapy on new bone formation was more prominent at the axial than the peripheral level. Collectively, our study showed that dual blockade therapy significantly reduces inflammation and structural changes, including new bone formation. However, we could not confirm a more pronounced effect of dual inhibition compared to single inhibition.

Axial spondyloarthritis

Axial spondyloarthritis (axSpA) encompasses both radiographic and non-radiographic axSpA. It is a chronic inflammatory disease with a predilection for involving the axial skeleton. The most common presenting symptoms are chronic back pain and spinal stiffness but peripheral and extra-musculoskeletal manifestations occur also frequently. The diagnosis of axSpA relies on the recognition of a clinical pattern of the disease, based on clinical, laboratory and imaging features. The Assessment in SpondyloArthritis international Society classification criteria for axSpA are valid and well implemented for research purposes. Sustained disease activity, measured by validated tools such as the Ankylosing Spondylitis Disease Activity Score, leads to irreversible structural damage and poor functioning and therefore should be abrogated. As part of the management algorithm, non-steroidal anti-inflammatory drugs remain as the first line of pharmacological treatment besides physiotherapy. As a second line, tumour necrosis factor inhibitor and interleukin-17 inhibitor are available but recently Janus kinase inhibitors have also shown efficacy in improving symptoms of the disease.

Biological DMARDs and disease modification in axial spondyloarthritis: a review through the lens of causal inference

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterised by inflammation predominantly involving the spine and the sacroiliac joints. In some patients, axial inflammation leads to irreversible structural damage that in the spine is usually quantified by the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Available therapeutic options include biological disease-modifying antirheumatic drugs (bDMARDs), which have been proven effective in suppressing inflammation in several randomised controlled trials (RCT), the gold standard for evaluating causal treatment effects. RCTs are, however, unfeasible for testing structural effects in axSpA mainly due to the low sensitivity to change of the mSASSS. The available literature therefore mainly includes observational research, which poses serious challenges to the determination of causality. Here, we review the studies testing the effect of bDMARDs on spinal radiographic progression, making use of the principles of causal inference. By exploring the assumptions of causality under counterfactual reasoning (exchangeability, positivity and consistency), we distinguish between studies that likely have reported confounded treatment effects and studies that, on the basis of their design, have more likely reported causal treatment effects. We conclude that bDMARDs might, indirectly, interfere with spinal radiographic progression in axSpA by their effect on inflammation. Innovations in imaging are expected, so that placebo-controlled trials can in the future become a reality. In the meantime, causal inference analysis using observational data may contribute to a better understanding of whether disease modification is possible in axSpA.

Tumor Necrosis Factor Inhibitors Reduce Spinal Radiographic Progression in Patients With Radiographic Axial Spondyloarthritis: A Longitudinal Analysis From the Alberta Prospective Cohort

Objective

To investigate whether tumor necrosis factor inhibitors (TNFi) impact spinal radiographic progression in patients with axial spondyloarthritis (SpA) and whether this is coupled to their effect on inflammation.

Methods

Patients with axial SpA fulfilling the modified New York criteria were included in a prospective cohort (the ALBERTA Follow Up Research Cohort in Ankylosing Spondylitis Treatment). Spine radiographs, performed every 2 years for up to 10 years, were scored by 2 central readers, using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The indirect effect of TNFi on mSASSS was evaluated with generalized estimating equations by testing the interaction between TNFi and Ankylosing Spondylitis Disease Activity Score (ASDAS) at the start of each 2‐year interval (t). If significant, the association between ASDAS at t and mSASSS at the end of the interval (t+1) was assessed in 1) patients treated with TNFi at all visits, 2) patients treated with TNFi at some visits, and 3) patients who were never treated with TNFi. In addition, the association between TNFi at t and mSASSS at t+1 (adjusting for ASDAS at t) was also tested (direct effect).

Results

In total, 314 patients were included. A gradient was seen for the effect of ASDAS at t on mSASSS at t+1 (interaction P = 0.10), with a higher progression in patients never treated with TNFi (β = 0.41 [95% confidence interval (95% CI) 0.13, 0.68]) compared to those continuously treated (β = 0.16 [95% CI 0.00, 0.31]) (indirect effect). However, TNFi also directly slowed progression, as treated patients had on average an mSASSS 0.85 units lower at t+1 compared to untreated patients (β = −0.85 [95% CI −1.35, −0.35]).

Conclusion

Our findings indicate that TNFi reduce spinal radiographic progression in patients with radiographic axial SpA, which might be partially uncoupled from their effects on inflammation as measured by the ASDAS.

Juvenile Spondyloarthritis: What More Do We Know About HLA-B27, Enthesitis, and New Bone Formation?

Juvenile spondyloarthritis (JSpA) refers to a diverse spectrum of immune-mediated inflammatory arthritides whose onset occurs in late childhood and adolescence. Like its adult counterpart, JSpA is typified by a strong association with human leukocyte antigen-B27 (HLA-B27) and potential axial involvement, while lacking rheumatoid factor (RF) and distinguishing autoantibodies. A characteristic manifestation of JSpA is enthesitis (inflammation of insertion sites of tendons, ligaments, joint capsules or fascia to bone), which is commonly accompanied by bone resorption and new bone formation at affected sites. In this Review, advances in the role of HLA-B27, enthesitis and its associated osteoproliferation in JSpA pathophysiology and treatment options will be discussed. A deeper appreciation of how these elements contribute to the JSpA disease mechanism will better inform diagnosis, prognosis and therapy, which in turn translates to an improved quality of life for patients.

Treatment strategies in axial spondyloarthritis: what, when and how?

There have been major advances in the management of axial spondyloarthritis (axSpA) with the introduction of effective biologic agents targeting TNF and IL-17A. Clinicians now have more choice but, despite treatment recommendations, are still faced with significant uncertainty when deciding on the optimal treatment strategy for an individual patient in clinical practice. Management of axSpA typically requires both non-pharmacological and pharmacological interventions. NSAIDs remain the first line drug therapies for axSpA with proven efficacy for symptomatic management but uncertainty remains regarding their optimal long-term use relating to radiographic progression and safety in axSpA. To-date there are no head-to-head trials of biologics in axSpA. Clinicians need to consider other factors, including extra-articular manifestations, comorbidities, safety and radiographic progression when deciding on which biologic to recommend for an individual patient. This article will explore the evidence relating to these factors and highlight areas of unmet need.

Recognizing Axial Spondyloarthritis: A Guide for Primary Care

Axial spondyloarthritis (axSpA) is an important cause of chronic low back pain and affects approximately 1% of the US population. The back pain associated with axSpA has a characteristic pattern referred to as inflammatory back pain (IBP). Features of IBP include insidious onset before age 45 years, association with morning stiffness, improvement with exercise but not rest, alternating buttock pain, and good response to treatment with nonsteroidal anti-inflammatory drugs. In patients with IBP, it is essential to look for other features associated with spondyloarthritis (SpA), such as enthesitis, dactylitis, peripheral arthritis, extra-articular manifestations (eg, psoriasis, uveitis, or inflammatory bowel disease), human leukocyte antigen B27 positivity, and a family history of SpA. Axial SpA is underrecognized, and a delay of several years between symptom onset and diagnosis is common. However, with new and effective therapies available for the treatment of active axSpA, early recognition and diagnosis are of critical importance. For this narrative review, we conducted a literature search of English-language articles using PubMed. Individual searches were performed to identify potential articles of interest related to axSpA (search terms: ["axSpA" OR "axial SpA" OR "axial spondyloarthritis" OR "ankylosing spondylitis"]) in combination with terms related to IBP ("inflammatory back pain" OR "IBP" OR "chronic back pain" OR "CBP" OR "lower back pain" OR "LBP"), diagnosis (["diagn∗" OR "classification"] AND ["criteria" OR "recommend∗" OR "guidelines"]), and referral ("refer∗"). No date range was formally selected, as we were interested in providing an overview of the evolution of these concepts in clinical practice. We supplemented the review with insights based on our clinical expertise. Patients with chronic back pain should be screened for IBP and other SpA features; suspicion for axSpA should trigger referral to a rheumatologist for further evaluation.

Trabecular bone loss contributes to radiographic spinal progression in patients with axial spondyloarthritis

OBJECTIVES

To investigate the longitudinal relationship between trabecular bone loss and spinal progression in axial spondyloarthritis (axSpA).

METHODS

Patients enrolled in the Incheon Saint Mary's axSpA prospective observational cohort were evaluated. The number of syndesmophytes was assessed by two trained readers at baseline and at 2 and 4 years follow-up. Trabecular bone loss was assessed using the trabecular bone score (TBS). Disease activity measures included the BASDAI, ASDAS, CRP, and ESR. The relationship between trabecular bone loss and radiographic damage was investigated using generalized estimating equation models with 2 year time lags.

RESULTS

Of the 245 patients included (80% males; mean (SD) age, 37 (12) years), 26 (11%) had mild trabecular bone loss (1.23-1.31) and 25 (10%) had severe trabecular bone loss (≤1.23) at baseline. Trabecular bone loss was associated with longitudinal radiographic spinal progression. Those with severe trabecular bone loss at baseline had an average 0.42 more syndesmophytes/2 years than those with normal TBS. Multivariate analysis revealed that severe trabecular bone loss compared with normal TBS resulted in an additional 0.4 syndesmophytes over 2 years. Adjusting for significant clinical factors revealed that both mild and severe trabecular bone loss were independent risk factors for new syndesmophyte formation over the next 2 years (OR [95% CI] = 2.4 [1.1-5.1]) and OR [95% CI] = 4.0 [1.6-9.7], respectively).

CONCLUSIONS

Trabecular bone loss is longitudinally associated with spinal progression of axSpA. The more severe the trabecular bone loss, the stronger the effect on the progression of the spine.

Biologic therapy and spinal radiographic progression in patients with axial spondyloarthritis: A structured literature review

We aimed to perform a structured literature review of spinal radiographic progression, as assessed by the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), in patients with ankylosing spondylitis (AS) or nonradiographic axial spondyloarthritis (nr-axSpA) treated with biologic therapy. Searches were limited to English language manuscripts published in the 11 years prior to 9 July 2019. Randomized controlled trials, open-label extensions (OLEs) and observational studies reporting mSASSS progression in patients with AS or nr-axSpA treated with biologics were eligible for inclusion. Bias was assessed using the methodological index for nonrandomized studies (MINORS) tool. Among the 322 studies identified in the literature search, 23 (11 OLEs and 12 cohort studies) met the eligibility criteria and were selected for inclusion. Most studies reported mSASSS progression in patients with AS receiving tumor necrosis factor inhibitor (TNFi) treatment. One study reported mSASSS progression in patients with AS treated with secukinumab, an interleukin-17A inhibitor. The mean (range) MINORS score was 11.3 (7-15) for the 15 noncomparative studies and 15 (12-22) for the 8 comparative studies. Although results of the individual studies were variable, mSASSS progression in patients with AS was generally minimal and slow with long-term TNFi therapy. Moreover, odds ratios for the likelihood of mSASSS progression with/without TNFi favoured TNFi therapy in several of the cohort studies. The rate of mSASSS progression following continuous secukinumab treatment was low and remained stable over 4 years. Of two studies reporting progression in patients with nr-axSpA treated with TNFis, one showed no mSASSS progression; however, the lack of control limited comparative conclusions.