Ixekizumab Survival in Heavily Pretreated Patients with Psoriasis: A Two-year Single-centre Retrospective Study

The long-term effect of intra-anti-interleukin-17-class switch on drug survival is unclear. The aim of this study was to evaluate the efficacy and long-term survival of ixekizumab in bio-experienced psoriatic patients with and without previous exposure to anti-interleukin-17 treatment. Retrospective search of a tertiary medical centre database for 2017 to 2019 yielded 73 patients treated with ixekizumab: 50 previously exposed to secukinumab and 23 anti-interleukin-17-naïve. Median baseline Psoriasis Area Severity Index (PASI) was 23.0. Median number of received biologics was 4. Mean drug survival was 16.4 and 16.8 months in the anti-interleukin-17-exposed and naïve groups, respectively (p = 0.878). There was no between-group difference in proportion of patients achieving ≥ 75 PASI response. At study end, 25 anti-interleukin-17-exposed patients (50.0%) and 17 anti-interleukin-17-naïve patients (73.9%) were still on ixekizumab. The use of multiple previous biologic treatments was associated with substantially reduced ixekizumab survival. In conclusion, previous anti-interleukin-17-exposure was associated with an initially favourable response and did not further reduce ixekizumab survival.