The Retention Rate and Safety of Secukinumab as a First-Line Biologic Agent in Axial Spondyloarthritis Compared to a First Tumor Necrosis Factor (TNF) Inhibitor: A Real-World, Longitudinal Study.

Background and objective Secukinumab (SECU) is a biologic disease-modifying antirheumatic drug (bDMARD) that has demonstrated effectiveness against axial spondyloarthritis (ax-SpA). However, in clinical practice, secukinumab is most commonly used as a second-line treatment after failure of or intolerance to tumor necrosis factor inhibitors (TNFi). In this study, we aimed to compare the two-year drug retention between secukinumab and TNFi in biologic-naïve patients with ax-SpA, to estimate the remission/low disease activity (LDA) rates in both groups and assess the safety profiles. Methods This was a longitudinal observational study involving patients with ax-SpA who were biologic-naïve and were receiving SECU or TNFi between December 2019 and December 2021. The two-year therapeutic retention rate in both groups was determined. Remission and LDA rates obtained at 24 months according to the Ankylosing Spondylitis Disease Activity Score based on C-reactive protein (ASDAS-CRP) scale, as well as the safety profile, were compared between the two groups. Results Seventy-five patients were included in the study. Of them, 34.6% received SECU, while 65.3% received TNFi; 85.3% were males. The mean age was 37.8 ±9 years, the mean disease duration was 10.2 ±6.1 years, and the initial ASDAS-CRP was 3.5 ±0.8. At 24 months; the therapeutic retention rate was 70% for SECU and 66% for TNFi. The reasons for discontinuation were inefficacy (SECU: 11.5%, TNFi: 20.4%, p=0.33), side effects (SECU: 0, TNFi: 4.1%, p=0.29), and socioeconomic conditions (SECU: 15.5%, TNFi: 10.2%, p=0.51). The rate of patients achieving remission and LDA was comparable between the two groups: (remission - SECU: 23.1%, TNFi: 24.5%, p=0.92; LDA - SECU: 73.1%, TNFi: 73.5%, p=0.16). There was no statistically significant difference in the safety profile. Conclusions Our findings suggest that the effectiveness and safety of secukinumab for ax-SpA in biologic-naïve patients are comparable to those of TNFi.