AB0953 PATTERNS OF bDMARDs PRESCRIPTION IN SPONDYLOARTHRITIS AFTER FIRST TNFi FAILURE
Authors: M. Diz Lopes, C. Gomes, I. Santos, T. Beirão, T. Martins-Rocha, M. Bernardes, L. Costa
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Patients with spondyloarthritis (SpA) using tumor necrosis factor inhibitors (TNFi) can have an inadequate response, with discontinuation rates of up to 50-60% in two years [1]. For several years, TNFis were the only biologic disease-modifying anti-rheumatic drugs (bDMARDs) available for SpA and the introduction of IL-17 inhibitors (IL-17i) changed the treatment paradigm [2]. Switching to another mechanism of action (MOA) or cycling to another TNFi after failure of first (1<sup>st</sup>) TNFi is still a debatable topic. <h3>Objectives:</h3> To describe clinical characteristics of patients using TNFi in the 1<sup>st</sup> year of treatment and identify relevant differences between patients who cycled TNFi or switched to MOA after failure of the 1<sup>st</sup> TNFi. <h3>Methods:</h3> We conducted a monocentric retrospective study that included patients with SpA according to ASAS classification criteria registered in Reuma.pt (Rheumatic Diseases Portuguese Register). All patients discontinued their 1<sup>st</sup> TNFi in the 1<sup>st</sup> year of treatment due to inefficacy and were grouped according to their second (2<sup>nd</sup>) bDMARD: TNFi cyclers or MOA switchers. Clinical and demographic data were collected. Statistical analysis included chi-square test for categorical variables and non-parametric tests for continuous variables. <h3>Results:</h3> A total of 44 patients, out of 629, fulfilled the inclusion criteria. Most were female (72,7%) and mean age at diagnosis was 39±11,9 years old. Ankylosing spondylitis was the most common SpA subtype (52,3%), followed by undifferentiated SpA (36,4%) and inflammatory bowel disease associated SpA (11,4%). Peripheral involvement was present in 38,6% patients. Amongst other clinical features, 50% of the patients had enthesitis, 22,7% had psoriasis, two patients had dactylitis and 5 patients had an history of uveitis. Regarding 1<sup>st</sup> TNFi therapy, adalimumab and golimumab were the choice in 36,4% (n= 16) of the patients, respectively. Etanercept (18,2%, n=8), infliximab (6,8%, n=3) and certolizumab (2,3%, n=1) were other 1<sup>st</sup> line therapeutic options. After discontinuation of the 1<sup>st</sup> TNFi, 37 (84,1%) patients cycled to another TNFi and 7 (15,9%) switched MOA. Moreover, 50% (n=22) of the patients started the 2<sup>nd</sup> bDMARD before 2017, which is relevant giving the timeline of IL-17i approval. Within MOA switchers, all patients were prescribed secukinumab (IL-17i). In this group, there was a tendency for longer treatment duration of 1<sup>st</sup> TNFi (10,8 (5,7-12,9) vs 8,8 (6,5-12,4) months) and HLA-B27 positivity (42,9% vs 24,3%), but this was not statistically significant. Patients that switched MOA showed a higher prevalence of psoriasis (57,1% vs 16,2%, p=0,037). Additionally, all patients using secukinumab as a 2<sup>nd</sup> therapeutic option were switched after the year of 2017 (p=0,009, Table 1). When comparing disease activity evaluation between TNFi cyclers and MOA switchers at the time of starting the 1<sup>st</sup> TNFi and before starting the 2<sup>nd</sup> bDMARD, there were no relevant differences. MOA switchers had higher prevalence of very high ASDAS activity levels, but this failed to reach statistical significance (p=0,437, Table 2). <h3>Conclusion:</h3> Patterns of bDMARDs prescription in SpA have been conditioned during several years due to the lack of therapeutic options other than TNFi. Since 2017, novel targets have emerged, and IL-17i have showed efficacy in controlling disease activity. In our study, 50% of the patients started the 2<sup>nd</sup> line bDMARD before 2017, so, as expected, most patients were TNFi cyclers. The presence of psoriasis was the only clinical factor associated with the decision of MOA switching, and this is in line with current evidence of better skin outcomes with IL-17i [2]. <h3>REFERENCES:</h3> [1] Bekele, D.I., et al., <i>Tumor necrosis factor inhibitor (TNFi) persistence and reasons for discontinuation in a predominantly male cohort with axial spondyloarthritis.</i> Rheumatol Int, 2022. 42(11): p. 1925-1937. [2] Ramiro, S., et al., <i>ASAS-EULAR recommendations for the management of axial spondyloarthritis: 2022 update.</i> Ann Rheum Dis, 2023. 82(1): p. 19-34. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>