Secukinumab for the Treatment of Axial Spondyloarthritis: Long-Term Real-Life Data from Five Italian Referral Centers

Background: This study aimed to evaluate the effectiveness and drug retention rate of secukinumab (SCK) in axial spondyloarthritis (ax-SpA) within a multicentric real-life cohort. Methods: Data from patients with ax-SpA treated with SCK at five Italian centers were collected retrospectively, excluding those with a diagnosis of Psoriatic Arthritis. Evaluations were conducted at baseline and at 3, 6, 12, 18, and 24 months. Assessments included C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), BASDAI, and ASDAS-CRP. Results: Seventy-one ax-SpA patients (57.7% female, mean age: 53.86 ± 12.67 years) were enrolled. Baseline mean BASDAI was 6.2 ± 1.4 and ASDAS-CRP was 2.9 ± 1.3. Significant improvements in BASDAI and ASDAS-CRP were observed over time, with BASDAI reducing to 3.5 ± 1.9 (p < 0.0001) and ASDAS-CRP to 1.7 ± 0.9 (p < 0.0001) at 24 months. The follow-up duration averaged 20.46 ± 13.46 months. By the end of follow-up, 29.5% of patients discontinued SCK. The two-year retention rate was 72%. Dropout risk was higher in patients with fibromyalgia (HR: 2.896, p = 0.026). No significant retention differences were found based on sex, age, enthesitis, radiographic disease, combination with cDMARDs, SCK dosage, or previous bDMARD exposure. Lower ASDAS-CRP at the study’s end was noted in patients without fibromyalgia (1.4 vs. 2.5, p < 0.001). Conclusions: SCK showed rapid and lasting effectiveness for ax-SpA with a favorable retention rate, though fibromyalgia may reduce treatment persistence.