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.