Background Long-term data on anti-TNF treatment in patients with ankylosing spondylitis (AS) are still scarce.
Objectives To study the long term efficacy and safety of anti-TNF agents in AS in a pan-European setting using data from daily practice.
Methods Patients from the EASIC and the DIKAS trial had been included in this 8-year observational study. Clinical data were collected every 2 years. All patients were initially treated with infliximab at the usual dosage (5mg/kg). Standard assessments were regularly performed, and adverse events (AEs) and serious AEs (SAEs) were documented. The data are presented as completer analysis.
Results Of initially 71 patients, 55 (77.5%) were included in this long-term extension study (46 male, 83.6%). Of these 55 patients, 7 (12.7%) switched from infliximab to another biologic for different reasons. At the end of the study, 31 patients (56.4%) received NSAIDs in addition to TNF-blockers. The mean doses of infliximab remained stable over time (4.7±0.6 mg/kg, min: 3.6, max: 6.4) but the infusion intervals increased (7.1±1.5 weeks, range 6-12 weeks). There was no correlation between the duration of infusion interval and the disease status achieved by the patients. Overall, the mean BASDAI (baseline (BL): 6.4, 2y: 2.4, 8y: 2.5), BASFI (BL: 5.9, 2y: 2.9, 8y: 3.5), BASMI (BL: 4.0, 2y: 2.7, 8y: 3.9), patient's global (BL: 7.0, 2y: 2.9, 8y: 2.9), and CRP (mg/dl) values (BL: 2.9, 2y: 0.6, 8y: 0.4) remained low throughout the entire observation period. The majority of adverse events were mild, most of them were respiratory tract infections. Two malignancies occurred: one basal cell carcinoma and one malignant melanoma, all during the first 7 years of treatment. These two were the only SAE judged to be possibly related to the study drug.
Conclusions This study confirms the favourable outcome of AS patients who complete anti-TNF therapy over many years. The persistently decreased BASDAI, BASFI and BASMI values suggest a good control of disease activity, in combination with preserved function and spinal mobility over 8 years. The observation that infusion intervals could be prolonged confirms that dose reduction of anti-TNF therapy is feasible.
Disclosure of Interest None declared