Ab0933 Is Primary Failure to an Anti-TNF a Predictor of a New Failure to a Second Anti-TNF in the Treatment of Spondyloarthritis?

Background: TNF alpha inhibitors (anti-TNFα) have demonstrated their efficacy and safety in the treatment of patients with spondyloarthritis (SpA) with high response and survival rates in the first line of treatment (1). Currently, the new recommendations on the treatment of SpA indicate that if a first-line anti-TNFα is ineffective, it can be switched to an anti-IL17 or to another anti-TNFα molecule (1)(2)(3). It seems that this switch to a second anti-TNFα does not decrease the efficacy of such treatment (1)(2)(3). Objectives: To analyze whether presenting a primary failure to a first anti-TNFα is associated with a new failure when initiating a second anti-TNFα molecule. Secondly, to compare the percentage of primary failure to an anti-TNFα vs anti-IL17. Methods: A descriptive, observational and retrospective study was carried out including patients diagnosed with spondyloarthritis under treatment with biologic drugs at the Hospital General Universitario Santa Lucia. Data were collected on the different lines of treatment and the reason for discontinuation, qualifying primary failure as that which occurred in the first three months after starting the biologic drug. Subsequently, a descriptive and statistical analysis was performed using the SPSSv23 program. Results: We obtained 289 patients diagnosed with spondyloarthritis under treatment with biologic drugs. In the first line of treatment, 85% were on an anti-TNFα molecule, 10% on an anti-IL17, 4.8% on an anti-IL12/23 and 0.2% on JAK inhibitor. 27% of patients on treatment with an anti-TNFα suffered a primary failure, making it necessary to initiate a second line of treatment, while this occurred in only 15.4% of individuals on treatment with an anti-IL17, however, these differences were not significant (p=0.227). Of the individuals who had failed to an anti-TNFα, 91% switched to a second anti-TNF, of whom 42% suffered a new primary failure. Thus, whereas with the first anti-TNFα only 27% suffered a primary failure, this percentage rises to 42% in individuals who initiated a second anti-TNF (see Figure 1). However, these differences were not significant, and there was no statistically significant association (p=0.789) between suffering a primary failure to an anti-TNFα and presenting it again when starting a second anti-TNF molecule. Conclusion: Presenting a primary failure to one anti-TNFα molecule does not seem to predict a new failure when starting a second anti-TNFα, the percentage of inefficacy being similar for the first and second anti-TNFα molecule. Second, we found no significant differences in the percentage of primary failure occurring between individuals on anti-IL17 and those on a TNFα inhibitor. REFERENCES: [1] Gratacós et al. Recomendaciones de la Sociedad Española de Reumatología sobre el uso de terapias biológicas en espondiloartritis axial. ReumatolClin.2018;14(6):320–333. [2] Lie E, van der Heijde D, Uhlig T, Mikkelsen K, Rødevand E, Koldingsnes W, Kaufmann C, Kvien TK. Effectiveness of switching between TNF inhibitors in ankylosing spondylitis: data from the NOR-DMARD register. Ann Rheum Dis. 2011 Jan;70(1):157-63. doi: 10.1136/ard.2010.131797. Epub 2010 Nov 9. PMID: 21062852. [3] Dadoun S, Geri G, Paternotte S, Dougados M, Gossec L. Switching between tumour necrosis factor blockers in spondyloarthritis: A retrospective mono centre study of 222patients. ClinExpRheumatol.2011;29:1010–3 Acknowledgements: NIL. Disclosure of Interests: None declared.