Evidence map›Paper›PMID 41335412›Full record

ArticleRheumatology (Oxford, England)2026

Frequency of difficult-to-manage and treatment-refractory axial SpA: insights from the German RABBIT-SpA register using recent ASAS definitions.

Fabian Proft, Stephanie Lembke, Anja Weiß, Herbert Kellner, Xenofon Baraliakos, Denis Poddubnyy, Anne C Regierer

Abstract readMulticenter Study
In one paragraph

Article in Rheumatology (Oxford, England), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Observational
  2. Review
  3. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Fabian ProftDepartment of Gastroenterology, Infectiology and Rheumatology (including Nutrition Medicine), Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.ORCID 0000-0003-4306-033X
Stephanie LembkeGerman Rheumatology Research Center (DRFZ Berlin), Epidemiology and Health Services Research, Berlin, Germany.ORCID 0000-0003-0426-0312
Anja WeißGerman Rheumatology Research Center (DRFZ Berlin), Epidemiology and Health Services Research, Berlin, Germany.ORCID 0000-0003-2069-2190
Herbert KellnerPrivate Practice for Rheumatology und Gastroenterology, Munich, Germany.
Xenofon BaraliakosRuhr Universität, Bochum, Germany.ORCID 0000-0002-9475-9362
Denis PoddubnyyDepartment of Gastroenterology, Infectiology and Rheumatology (including Nutrition Medicine), Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.ORCID 0000-0002-4537-6015
Anne C RegiererGerman Rheumatology Research Center (DRFZ Berlin), Epidemiology and Health Services Research, Berlin, Germany.ORCID 0000-0003-2456-4049

Funding

AbbVieAmgenBiocon BiologicsBiogenCelltrionJanssen-CilagLillyNovartisPfizerRABBIT-SpAUCB
6 · The paper itself

Abstract

objectivesTo determine the frequency of axial SpA (axSpA) patients fulfilling the recently proposed Assessment of SpondyloArthritis International Society (ASAS) definitions for difficult-to-manage (D2M) and treatment-refractory (TR) axSpA, and to characterize these patients at initiation of their first advanced therapy.

methodsData were derived from the ongoing prospective, multicentre, longitudinal German RABBIT-SpA registry. Patients were eligible if they were biologic and targeted synthetic (b/ts) DMARD-naïve, had initiated a b/tsDMARD and had ≥12 months of follow-up. ASAS definitions were applied to identify cases of D2M and TR.

resultsOf 1850 patients with axSpA, 881 (48%) were b/tsDMARD-naïve at the start of observation. A total of 75/881 patients (8.5%) fulfilled the ASAS criteria for D2M and 22/881 (2.5%) additionally met the criteria for TR. At baseline, D2M patients were more frequently female, more often HLA-B27-negative, and more commonly presented with arthritis and enthesitis compared with not-D2M (nD2M) patients. In addition, they exhibited fewer objective inflammatory markers such as elevated CRP or MRI lesions. Opioid use was higher across D2M patients compared with nD2M patients. In the TR group compared with the D2M/nTR, the proportion of female and of obesity was lower. Even at initiation of first-line b/tsDMARD, these patients showed more frequently signs of inflammation, including sacroiliac/spinal MRI lesions and elevated CRP, while peripheral arthritis was less frequent.

conclusionApplying the ASAS definitions in a large real-world cohort identified clinically relevant subgroups with D2M and TR. These findings support their clinical utility and highlight the need for phenotype-specific management strategies.

Indexed as

Antirheumatic AgentsAxial SpondyloarthritisAdultBiological ProductsFemaleGermanyHumansMaleMiddle AgedProspective StudiesRegistriesAntirheumatic AgentsBiological Productsaxial spondyloarthritisbiologic therapydifficult-to-manage axSpAobservational studypatient-reported outcomesreal-world datatreatment failuretreatment-refractory axSpA

Identifiers

PMID41335412
PMCPMC12822491

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.