Nationwide Experience With Off‐Label Use of Interleukin‐1 Targeting Treatment in Familial Mediterranean Fever Patients

Objective Approximately 30–45% of patients with familial Mediterranean fever (FMF) have been reported to have attacks despite colchicine treatment. Currently, data on the treatment of colchicine‐unresponsive or colchicine‐intolerant FMF patients are limited; the most promising alternatives seem to be anti–interleukin‐1 (anti–IL‐1) agents. Here we report our experience with the off‐label use of anti–IL‐1 agents in a large group of FMF patients. Methods In all, 21 centers from different geographical regions of Turkey were included in the current study. The medical records of all FMF patients who had used anti–IL‐1 treatment for at least 6 months were reviewed. Results In total, 172 FMF patients (83 [48%] female, mean age 36.2 years [range 18–68]) were included in the analysis; mean age at symptom onset was 12.6 years (range 1–48), and the mean colchicine dose was 1.7 mg/day (range 0.5–4.0). Of these patients, 151 were treated with anakinra and 21 with canakinumab. Anti–IL‐1 treatment was used because of colchicine‐resistant disease in 84% and amyloidosis in 12% of subjects. During the mean 19.6 months of treatment (range 6–98), the yearly attack frequency was significantly reduced (from 16.8 to 2.4; P < 0.001), and 42.1% of colchicine‐resistant FMF patients were attack free. Serum levels of C‐reactive protein, erythrocyte sedimentation rate, and 24‐hour urinary protein excretion (5,458.7 mg/24 hours before and 3,557.3 mg/24 hours after) were significantly reduced. Conclusion Anti–IL‐1 treatment is an effective alternative for controlling attacks and decreasing proteinuria in colchicine‐resistant FMF patients.