AB0551 TREATMENT WITH IXEKIZUMAB FOLLOWING SECUKINUMAB FAILURE IN PATIENTS WITH PSORIATIC ARTHRITIS: REAL-LIFE EXPERIENCE FROM A RESISTANT POPULATION

Background: Anti-IL17 agents, such as Secukinumab (SEC) and Ixekizumab (IXE) have been shown to be efficacious for the treatment of psoriasis and PsA12. In the field of psoriasis, there is growing evidence of a successful switching between the two anti-IL-17 agents in case of an insufficient response to one of the treatments3 There is no information on the efficacy of switching between anti IL17 agents in PsA. Objectives: To assess the clinical response to IXE in patients with PsA following SEC failure. Methods: A retrospective observational study was conducted in two rheumatology centers in Israel, including PsA patients with a history of treatment with SEC, further treated with IXE for a minimum of 3 months. Lack of efficacy, loss of efficacy, and side effects over time were reported as a reason for switching to another anti-IL17 agent. The mean difference between the beginning of the follow up period and the different follow up points (6 and 12 months) was tested using a one-sample t-test. Time until treatment failure was estimated using Kaplan–Meier curves, and compared using the log-rank test. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated using the Cox proportional-hazards model to test the association between each variable and the time to treatment failure. Results: The study included 23 PsA patients (11♀/12♂), mean age 58.7 years±13.4 SD. Most patients (n=20, 86%) received 2+ TNFi and 10 patients (43%) received both TNFi and ustekinumab. Median number of biologics prior to SEC was 3 (IQR 2-4). There was a significant improvement in TJC at 6 and 12 months (-2.16 [-4.0, -0.3]; p=0.025 and-1.69 [-3.09, -0.28]; p=0.022, respectively). SJC was significantly improved at 6 months but not at 12 months (-2.68 [-5.3, -0.04]; p= 0.046 and -1.50 [-4.25,1.25]; p=0.26, respectively). CDAI score was significantly improved at 6 months (-10.19, [-16.26, -4.1], p=0.002) and at 12 months (-9.29 [-14.8, -3.71], p=0.003) as was SDAI score (-10.13 [-16.4, -3.8], p=0.003 and -12.2 [-17.1, -7.2], p=0.0002). At six months, PASI50 was achieved by 81% (13 patients), PASI75 was achieved by 63% (10 patients), PASI90 was achieved by 50% (8 patients) and PASI100 by 31% (10 patients). At 12 months, PASI50 and PASI75 was achieved by 57% (8 patients), PASI90 was achieved by 43% (6 patients) and PASI100 by 21% (3 patients). Over time, of the 23 patients treated with IXE, 15 patients (65%) had experienced treatment failure, with a median treatment period of 8 months (IQR 6.5-13.5), of which 4 (17%) had primary treatment failure and 11 patients (48%) secondary treatment failure. Reasons for treatment cessation were: worsening psoriasis (4 patients (27%)), worsening peripheral arthritis (4 patients (27%)), both (7 patients (47%)), worsening of axial disease (2 patients (13%)) and adverse events (1 patient, 6%). Conclusion: patients after failure of multiple biologic treatments experienced significant response of peripheral arthritis and dermatologic disease on IXE after they had previously failed SEC. . However, in this refractory cohort of PsA, the effect was limited on time with 65% failure after a median time of 8 months.Within class switch from SEC to IXE is a plausible therapeutic option in PsA patients following secukinumab failure. References: [1]Mease PJ, McInnes IB, Kirkham B, et al. N Engl J Med. 2015;373(14):1329-1339. [2]Nash P, Kirkham B, Okada M, et al. Lancet Lond Engl. 2017;389(10086):2317-2327. [3]Bokor-Billmann T, Schakel K. J Dermatol Treat. 2019;30(3):216-220 Disclosure of Interests: None declared.