Drug switching in patients with psoriatic arthritis treated with tumor necrosis factor inhibitor.

Background Psoriatic arthritis (PsA) is a chronic inflammatory arthritis, characterized by different clinical manifestations and associated comorbidities that requires targeted treatment. Therapy with Tumor necrosis factor inhibitor (TNFi) represents one of first therapeutic choices. However, PsA patients can experience TNFi failure, lack of efficacy, or adverse events. Although rheumatologists are now able to choose between several drugs, there is a lack of standard patient profiles or detailed treatment algorithms that can be followed when patients need to switch their therapy regimens. Objectives To evaluate the switching treatments regardless the cause in patients with PsA treated with TNFi as first biologic agent. Methods Retrospective longitudinal observational study. Subjects: Cohort of patients attended in the outpatient rheumatology clinic from January 2006 to December 2021, and followed up to June 2022, diagnosed with PsA according to ICD-10 code and on treatment with TNFi. Main outcome : Therapy regimens switching. Covariables: sociodemographic and clinics. Statistical analysis: Descriptive analysis of the switching therapy, global and stratified by treatment courses. Results 125 patients with a diagnosis of PsA and on treatment with TNFi were included, 52% were female, the mean age was 47.87 ± 13.29 years. 94 (75.20%) patients had a history psoriasis at baseline and 95 patients (76%) presented peripheral arthritis and 21 (16.80%) referred inflammatory low back pain as a main clinical domain, 50% of the patients presented at least three PsA domains. 232 courses of treatment were recorded throughout follow-up. As a whole, TNFi was the most used drug with 184 (79.31%) courses, adalimumab 78 (42.39), flowed by interleukin-17 inhibitors (IL-17i) with 30 (12.93%) courses of treatment. 82 (65.60%) patients were on concomitant treatment with conventional DMARDs. From the 125 patients, 49 recorded a switching to a second therapy regimen (32 switched to a second TNFi and 17 to another class of drugs, mainly IL-17i). Then, 28 presented a third change (16 to a different TNFi and 12 switched to another class of drugs) and finally 14 patients had a fourth switching (8 patients received a drug other than TNFi). TNFi switching data expressed in course of treatment is shown in Table 1. Switching after TNFi exposure was mainly due to lack of efficacy with 90 (84.11%) courses of treatment, followed by adverse events with 11 (10.28%). Conclusion In our study, although most of the TNFi switching was to a different TNFi, we observed a number of PsA patients receiving another class of drugs after TNFi exposure, and this action increased over the consequent treatment cycles. Table 1. Courses of switching treatment in PsA patients treated with TNFi. Total Courses of treatment N (%) Frist cycle Courses of treatment N (%) Second cycle Courses of treatment N (%) Third cycle Courses of treatment N (%) Abatacept 2 (0.86) 0 0 0 Interleukin-17 inhibitors 30 (12.93) 0 3(5.26) 27(54) Ustekinumab 4 (1.73) 0 0 4 (1.73) Guselkumab 4 (1.73) 0 0 4 (1.73) JAK inhibitors 8 (3.45) 0 0 8 (3.45) Tumor necrosis factor inhibitors 184 (79.31) 125 (67.93) 54 (29.35) 5 (2.72) Total 232 (100) 125 (53.88) 57 (24.57) 50 (21.55) REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests None Declared.