Treatment response and drug retention rates in 24 195 biologic-naïve patients with axial spondyloarthritis initiating TNFi treatment: routine care data from 12 registries in the EuroSpA collaboration

Genetics and the axial spondyloarthritis spectrum

The axial SpAs (axSpAs) are clearly clinically a heterogeneous set of diseases with markedly varying extra-articular features. These diseases are all highly heritable and have overlapping but differing genetic origins. Shared features include association with HLA class I alleles and genes of the IL-23 pathway, among other things. Significant differences do exist however, both in the genetic loci involved and at specific loci in the individual genetic variants associated with each disease. These similarities and differences are of great interest in regards to disease pathogenesis and treatment development, although individually they are too small in effect to be of prognostic or diagnostic value. Polygenic risk scores, which capture a high proportion of the genetic variation between disorders, have been shown to have clinically useful discriminatory capacity in axSpA. This suggests they have the potential to enable improved disease classification, incorporating basic pathogenic features such as genomics, and ultimately benefitting clinical care. The aim of this article is to review the genetic characteristics of the spectrum of axSpAs and to discuss how this influences our understanding of the disease pathogenesis and the clinical implications of this understanding.

Impact of discordance between patient's and evaluator's global assessment on treatment outcomes in 14 868 patients with spondyloarthritis

OBJECTIVES

To assess the impact of 'patient's minus evaluator's global assessment of disease activity' (ΔPEG) at treatment initiation on retention and remission rates of TNF inhibitors (TNFi) in psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) patients across Europe.

METHODS

Real-life data from PsA and axSpA patients starting their first TNFi from 11 countries in the European Spondyloarthritis Research Collaboration Network were pooled. Retention rates were compared by Kaplan-Meier analyses with log-rank test and by Cox regression, and remission rates by χ2 test and by logistic regression across quartiles of baseline ΔPEG, separately in female and male PsA and axSpA patients.

RESULTS

We included 14 868 spondyloarthritis (5855 PsA, 9013 axSpA) patients. Baseline ΔPEG was negatively associated with 6/12/24-months' TNFi retention rates in female and male PsA and axSpA patients (P <0.001), with 6/12/24-months' BASDAI < 2 (P ≤0.002) and ASDAS < 1.3 (P ≤0.005) in axSpA patients, and with DAS28CRP(4)<2.6 (P ≤0.04) and DAPSA28 ≤ 4 (P ≤0.01), but not DAS28CRP(3)<2.6 (P ≥0.13) in PsA patients, with few exceptions on remission rates. Retention and remission rates were overall lower in female than male patients.

CONCLUSION

High baseline patient's compared with evaluator's global assessment was associated with lower 6/12/24-months' remission as well as retention rates of first TNFi in both PsA and axSpA patients. These results highlight the importance of discordance between patient's and evaluator's perspective on disease outcomes.

Associations of Platelet Count with Inflammation and Response to Anti-TNF-α Therapy in Patients with Ankylosing Spondylitis

Background: Increased platelet count has been reported in ankylosing spondylitis (AS) patients, but its clinical significance is still largely elusive. The objective of this study was to evaluate the clinical role of platelet count in AS patients, especially its impact on treatment outcomes.

Methods: A case-control study containing 35 AS patients receiving anti-tumor necrosis factor-α (anti-TNF-α) therapy and 45 healthy controls was performed, and AS patients were followed at least 6 months after anti-TNF-α therapy. A systematic review and meta-analysis of studies containing relevant data on outcomes of interest was also performed.

Results: AS patients had significantly higher platelet count than controls (p = 0.0001), and the significantly increased platelet count in AS patients was confirmed in a meta-analysis of 14 studies involving 1,223 AS patients and 913 controls (mean difference = 39.61, 95% CI 27.89–51.34, p < 0.001). Besides, platelet count was significantly correlated with ESR (p < 0.001) and was moderately correlated with ASDAS-CRP score (p = 0.002). Moreover, anti-TNF-α therapy could reduce platelet count in AS patients at the first month and the effect was maintained through the treatment duration. In the prospective follow-up study of those 35 AS patients, those responders to anti-TNF-α therapy had significantly lower platelet count than nonresponders (p = 0.015). Logistic regression analysis suggested that lower platelet count was associated with higher possibility of achieving good response to anti-TNF-α therapy in AS patients (odds ratio = 2.26; 95% CI = 1.06–4.82; p = 0.035).

Conclusion: This study suggested that platelet count was associated with inflammation severity and treatment outcomes in AS patients, and elevated platelet count was a promising biomarker of poorer response to anti-TNF-α therapy. The findings above need to be validated in more future studies.

Non-radiographic axial spondyloarthritis

Non-radiographic axial spondyloarthritis (nr-axSpA) is a subgroup of axial spondyloarthritis (axSpA) without fulfilling the modified New York criteria of sacroiliac joint radiographs for ankylosing spondylitis (AS). AS and nr-axSpA share various demographic and clinical features and disease burden, although sex and objective inflammatory findings such as elevated serum C-reactive protein level are slightly different between AS and nr-axSpA. Recently, diagnostic guidance for nr-axSpA in Japan was proposed for epidemiological studies of a population with a low prevalence of HLA-B27 positivity and the use of molecular targeted agents suitable for the unique medical care system in Japan. A biological agent targeting interleukin-17 was approved for nr-axSpA by the Pharmaceutical and Medical Devices Agency (PMDA) in August 2020. Some other biological agents will be also available for Japanese patients with nr-axSpA in the near future.

Retention Rate and Efficacy of the Biosimilar CT-P13 Versus Reference Infliximab in Patients with Ankylosing Spondylitis: A Propensity Score-Matched Analysis from the Korean College of Rheumatology Biologics Registry

Background

Long-term, real-world data are required to support the use of CT-P13 in chronic conditions such as ankylosing spondylitis. However, real-world evidence may be influenced by selection bias, which can confound outcomes. The aim of the current analysis was to confirm the long-term comparability of CT-P13 and reference infliximab treatment in patients with ankylosing spondylitis, using propensity score matching to adjust for baseline differences between groups.

Methods

A propensity score–matching analysis was conducted on data from patients with ankylosing spondylitis in the Korean College of Rheumatology Biologics registry who received CT-P13 or reference infliximab. Drug retention, reasons for biologic therapy changes or discontinuation, and efficacy parameters were analyzed overall and by treatment line with up to 4 years of follow-up. Adverse events were recorded for each treatment group.

Results

Propensity score matching was effective in matching 124 CT-P13–treated and 124 reference infliximab-treated patients. Median treatment duration and drug retention were similar between CT-P13 and reference infliximab. Three-year retention rates (95% confidence interval [CI]) were 64.2% (53.5–73.0) for CT-P13 and 55.6% (42.9–66.6) for reference infliximab. Overall, 17.1% (CT-P13) and 29.3% (reference infliximab) of patients discontinued biologic therapy, and 20.0% (CT-P13) and 15.2% (reference infliximab) changed biologic therapy. Efficacy assessments were generally similar between groups; both treatments were well tolerated.

Conclusions

Propensity score–matching analysis confirmed that CT-P13 treatment was not associated with significant differences in drug retention, treatment duration, most efficacy parameters, or safety versus reference infliximab in Korean patients with ankylosing spondylitis, building evidence for the long-term comparability of these treatments.

Trial registration

ClinicalTrials.gov identifier: NCT01965132.

Electronic supplementary material

The online version of this article (10.1007/s40259-020-00432-z) contains supplementary material, which is available to authorized users.

Response to lower dose TNF inhibitors in axial spondyloarthritis; a real-world multicentre observational study

OBJECTIVE

Dose optimization of TNF inhibitors in axial spondyloarthritis (axSpA) is attractive, but it is unclear for which patients this approach might be appropriate.

METHODS

Seventy-one patients with axSpA, from six UK centres, were identified who had reduced their dose of TNF inhibitor after being considered to be stable responders. All completed a questionnaire concerning their approach to and experience of dose reduction. Data on patient characteristics, metrology and CRP were retrieved retrospectively from patient records.

RESULTS

Over 2 years of observation, 60 (84.5%) remained (REM) on reduced-dose medication and 11 (15.5%) reverted (REV) to the original dose. The overall mean dose reduction was 39% for REM patients and 44% for REV patients. Both groups initially responded in a similar manner to treatment, but the data showed a trend that younger women were more likely to revert. Neither BMI nor smoking was associated with continued low-dose responsiveness. Eight of the 11 REV patients reverted by 6 months. None reached criteria of secondary drug failure, and all regained control after increasing back to the original dose. Most patients in both groups reached the decision to reduce the dose jointly with clinicians. A preference for taking the reduced dose was not associated with low-dose drug survival.

CONCLUSION

Many patients with axSpA remain well symptomatically after stepping down the dose of TNF inhibitor, but young women are less likely to do well on a reduced dose. Dose reduction should be one element of the management of patients with axSpA.