0533: Remission in Axial Spondyloarthritis: Is There a Difference Between NSAIDs and b/tsDMARDs in Daily Practice?

Francesco Natalucci¹, Pauline KRUG², Angela DE SOUSA LEITE², Tatiana Sokolova³, Patrick Durez⁴, Maria S. Stoenoiu² and Adrien NZEUSSEU TOUKAP⁵, ¹UCLouvain University, Sermoneta, Italy, ²Cliniques Universitaires Saint-Luc, Brussels, Belgium, ³Université Catholique de Louvain, Brussels, Belgium, ⁴UCLouvain, Brussels, Belgium, ⁵Cliniques universitaires Saint-Luc, St.-Lambrechts-Woluwe, Belgium

Background/Purpose: Randomized-controlled trials (RCTs) done in axial spondyloarthritis (axSpA) patients have shown that remission in axSpA (including nonradiographic axSpA) patients treated without b/tsDMARDs (TNFα blockers, IL-17A blockers, JAK inhibitors)(BIOL) occurs infrequently. Few are known about remission rate (RR) with large cohort in daily clinical practice.

The purpose of this study was to assess the remission rate (RR) in axSpA patients in the real life, and to compare the RR in axSpA patients on NSAIDs to RR for those on BIOL.

Methods: This cross-sectional study reviewed clinical data from a single center from 01/2013 to 01/2023. Last visit available for clinical assessment was evaluated. Disease activity was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and the Ankylosing Spondylitis Disease Activity Score (ASDAS) using the C-reactive protein. Remission was defined as BASDAI < 4 and ASDAS < 1,3.

Results: Data from 873 axSpA patients were reviewed. 529 were men (60.3 %). In the entire cohort, 653 BASDAI and 409 ASDAS were recorded. The RR according to the BASDAI was 46.7% (n =305), and 20.3 % for the ASDAS (n = 83). To look for the treatment-related RR, we stratified by the treatment (NSAIDs vs Biologics). We had 441 patients on NSAIDs (250 men, 56.7 %) and 432 on BIOL (279 men, 64.6 %). 287 BASDAI were available for NSAIDs and 366 for BIOL. 132 patients on NSAIDs (46 %) and 173 on BIOL (47.3%) were in remission for BASDAI. Regarding ASDAS (table below), data from 158 patients on NSAIDs and 251 on BIOL were available. Out of them, 34 (21.5 %) and 49 (19.5 %) were in remission for NSAIDs and BIOL respectively. Chi-square test: p = NS.

Table: Distribution of ASDAS values in both groups.

	ASDAS < 1.3	ASDAS ≥ 1.3 < 2.1	ASDAS ≥ 2.1 ≤3.5	ASDAS > 3.5
NSAIDs (n = 158)	N = 34 (21.5%)	N = 35 (22.2%)	N = 60 (38%)	N = 29 (18.4%)
BIOL (n = 251)	N = 49 (19.5%)	N = 58 (23.1%)	N = 93 (37.1%)	N = 51 (20.3%)

Conclusion: Based on the ASDAS, The overall RR in our axSpA cohort was around 20%, even in the NSAIDs group. When we added patients on low disease activity (LDA) according to the ASDAS score, the overall proportion of patients with inactive disease or LDA was quite the same in both groups and slightly above 40 %. In daily practice, we should probably better define the remission in axSpA.


F. Natalucci: None; P. KRUG: None; A. DE SOUSA LEITE: None; T. Sokolova: None; P. Durez: None; M. Stoenoiu: None; A. NZEUSSEU TOUKAP: None.