Efficacy and Safety of Secukinumab in Enthesitis-Related Arthritis: A Retrospective Study in China

Enthesitis-related arthritis (ERA) is a form of chronic inflammatory arthritis. Even when administered with a combination of non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), and biologics, some patients remain in an active disease state. Antecedent studies have revealed that interleukin-17 (IL-17) plays an important role in the pathogenesis of ERA and have demonstrated the efficacy of IL-17 inhibitors. This real-world, retrospective study aimed to assess the efficacy and safety of secukinumab in patients with ERA.

This was a retrospective, single-center cohort study of 31 Chinese patients who had been diagnosed with ERA and treated with secukinumab for at least 3 months. The primary outcomes were the proportion of patients achieving JIA ACR 30/50/70/90/100 response criteria and ACR inactive disease, as well as the change in Juvenile Spondyloarthritis Disease Activity (JSpADA) Index from baseline. Secondary outcomes included changes in the number of joints with active arthritis and enthesitis, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Outcomes were assessed every 3 months after secukinumab initiation. The Wilcoxon signed-rank test and paired t-test were used to analyze the data.

Male predominance (24/31, 77.4%), late disease onset, HLA-B27 positivity (13/31, 41.9%), and enthesitis (10/31, 32.3%) were the key characteristics of our cohort. The median follow-up duration was 0.9 years (ranging from 0.4 to 2.7 years). At the last follow-up, ACR 30/50/70/90/100 response rates were 87% (27/31), 68% (21/31), 65% (20/31), 32.3% (10/31) and 12.9% (4/31); 25.8% (8/31) of patients achieved ACR inactive disease. JSpADA scores decreased from baseline (median 5.0, IQR: 3.5-5.0) to month 3 (median 3.5, IQR: 2.5-4.0; median difference = 1.25, Z = -4.26, p < 0.001, 95% CI: 0.8 to 2.0), to month 6 to 3.0 (IQR: 2.0-4.0; median difference = 1.5, Z = -3.85, p < 0.001, 95% CI: 1.0 to 2.3), month 9 to 3.0 (IQR: 1.0-3.0; median difference = 2.3, Z = -3.09, p = 0.002, 95% CI: 1.5 to -3.0) and month 12 to 2.5 (IQR: 1.0-3.0; median difference = 2.25, Z = -2.95, p = 0.003, 95% CI: 1.5 to 3.3). The mean active joint count decreased from 9.3 ± 0.7 at baseline to 3.3 ± 0.5 at 12 months. Normalization of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) was observed.

In this retrospective, single-center study, secukinumab appears to be associated with improvement in arthritis and disease activity in Chinese children with ERA. Further studies are needed to investigate the correlation between IL-17 and ERA.