Abstract
BACKGROUND: Older adults are under-represented in clinical trials investigating spondyloarthritis (SpA), limiting the generalizability of efficacy and safety data for this population. In this context, real-world evidence on drug retention and treatment discontinuation is essential to guide long-term therapeutic decisions, particularly for biologic disease-modifying antirheumatic drugs (bDMARDs) and apremilast. OBJECTIVES: This study aimed to assess the 24-month retention rates of bDMARDs and apremilast in patients aged ≥ 60 years with SpA. METHODS: This was a single-center, observational study conducted over 24 months at Azienda Ospedaliero-Universitaria Policlinico "Gaspare Rodolico - San Marco" Catania. Patients aged ≥ 60 years with SpA, classified according to the Assessment of Spondyloarthritis International Society (ASAS) or the ClASsification criteria for Psoriatic ARthritis (CASPAR) criteria, were included if they initiated bDMARD or apremilast therapy during the study period. The primary outcome was bDMARD and apremilast retention at 6, 12, and 24 months. Kaplan-Meier survival analysis was used to assess drug retention, and reasons for discontinuation were analyzed. RESULTS: A total of 100 patients (66% female; mean age 64.17 ± 0.48 years) were included. Retention rates declined progressively, with 42% remaining on their initial therapy at 24 months. The most common reasons for discontinuation were adverse events (48%) and lack of efficacy (35%). Interleukin-17 (IL-17) inhibitors, particularly secukinumab, demonstrated superior retention compared with TNF-α inhibitors in patients with prior biologic failures. CONCLUSIONS: Retention of bDMARDs and apremilast in older SpA patients declines over time, with adverse events and inefficacy as key discontinuation drivers. IL-17 inhibitors exhibited better retention, suggesting a potential advantage in this population. Given the impact of comorbidities and treatment safety, personalized treatment strategies and further real-world studies are needed to optimize care in older SpA patients.