Retention rate and effectiveness of secukinumab vs TNF inhibitor in ankylosing spondylitis patients with prior TNF inhibitor exposure

Objectives: The choice of second-line biologics for AS patients previously treated with a TNF inhibitor (TNFi) remains unclear. Here, we compared drug retention and clinical efficacy between AS patients who switched biologics to secukinumab and those who switched to a different TNFi. Methods: AS patients enrolled in the Korean College of Rheumatology BIOlogics registry were included, and patients with non-radiographic axial spondyloarthritis were excluded. Patients with previous TNFi exposure were divided into the secukinumab group and the TNFi switching group. Drug retention and clinical efficacy [BASDAI50, Assessment of Spondylo-Arthritis International Society (ASAS)20, ASAS40, AS disease activity score (ASDAS) <2.1, ASDAS clinically important improvement and ASDAS major improvement] were assessed at the 1 year follow-up. Propensity score (PS)-matched and covariate-adjusted logistic regression analyses were performed. Results: Two hundred and forty-six had available 1 year follow-up data. Secukinumab as third- or later-line biologic was more frequent than alternative TNFi (54% vs 14%). PS-matched and multiple covariate-adjusted analyses showed that the odds ratio (OR) for drug discontinuation was comparable between the secukinumab and TNFi switching groups [OR 1.136 (95% CI 0.843, 1.531) and 1.000 (95% CI 0.433-2.308), respectively]. The proportion of patients who achieved BASDAI50 was also comparable between the two groups [OR 0.833 (95% CI 0.481, 1.441) in PS-matched analysis]. Other clinical efficacy parameters were also comparable. In the subgroup analysis of AS patients with previous TNFi discontinuation due to ineffectiveness, all clinical efficacy parameters were comparable between the two groups. Conclusion: In AS patients with previous exposure to a TNFi, switching biologics to secukinumab and switching to an alternative TNFi resulted in comparable drug retention and clinical efficacy.