Adherence to therapy of ixekizumab and secukinumab in psoriatic arthritis patients using first- or second-line IL-17A inhibitor treatment: a Danish population-based cohort study

To assess the effectiveness and tolerability of first- and second-line interleukin (IL)-17A inhibitor treatment in patients with psoriatic arthritis (PsA) from 2014 to 2021, using data from the Danish Rheumatology Registry (DANBIO) by investigating adherence to therapy.PsA patients recorded in DANBIO who received a first- or second-line IL-17A inhibitor treatment were included in this study. All patients included had previously received ≥1 TNFi treatment. Baseline characteristics were analyzed in subgroups: first-line IL-17A inhibitor treatment and second-line IL-17A inhibitor treatment. adherence to therapy of first- or second-line IL-17A inhibitor treatments were reported as Kaplan-Meier plots.534 patients were included in the study; first-line switchers: 534 (secukinumab: 510, ixekizumab: 24), second-line switchers: 102 (secukinumab: 35, ixekizumab: 67). Baseline characteristics showed a similar Health Assessment questionnaire (HAQ) and Visual Analogue Scale (VAS) pain. VAS global, Disease Assessment Score-28CRP and previous number of bDMARD treatments are similar with a greater value for second-line switchers. First-line ixekizumab treated patients present a younger age, greater percentage of females, a lower disease duration and a lower CRP value. Concomitant MTX use was greater for the first-line secukinumab treated patients. First- and second-line switchers had a similar adherence to therapy. Second-line secukinumab and second-line ixekizumab switchers showed a similar adherence to treatment.PsA patients receiving first- or second-line IL-17A inhibitors showed homogeneous baseline characteristics and similar adherence to therapy. Treatment failure of the first IL-17A inhibitor treatment should not preclude a second-line IL-17A inhibitor treatment.