Canakinumab in Children with Familial Mediterranean Fever: A Single-Center, Retrospective Analysis

Familial Mediterranean fever (FMF) is an autoinflammatory disease characterized by interleukin (IL)-1 overproduction. Colchicine is the mainstay drug in the treatment of FMF; however, a minority of patients do not respond despite the highest tolerated doses. We aimed to share our experience with canakinumab, a human monoclonal antibody against IL-1β, in pediatric FMF patients.

This historical, single-cohort study retrospectively evaluated the disease characteristics, indications, and treatment responses of 14 pediatric FMF patients treated with canakinumab in our pediatric rheumatology department.

The median age at onset and diagnosis of 14 FMF patients (9 females, 5 males), were 3.5 (range 0.5–10) years and 6 (range 3–16) years, respectively. Indications for canakinumab treatment were renal amyloidosis (n = 1), colchicine resistance (n = 11), and persistent arthritis (n = 2). Only two (14.3%) patients had colchicine intolerance. Complete response was obtained in 10/14 (71.5%) among all patients and 10/12 (86%) in patients with typical phenotype. The patient with chronic oligoarthritis had a complete response, whereas the patient with rheumatoid factor (RF)-positive polyarthritis demonstrated an initial partial response to canakinumab treatment. We found that attack frequency, proteinuria, and acute phase reactants, including erythrocyte sedimentation rate and C-reactive protein, were significantly decreased after canakinumab treatment in children with FMF.

Canakinumab may be an effective treatment option for pediatric FMF patients with colchicine resistance, renal amyloidosis, and chronic oligoarthritis. Further studies are needed to clarify the efficacy of canakinumab in patients with a second disease, RF-positive polyarticular juvenile idiopathic arthritis.