Background/Purpose: Familial Mediterranean fever (FMF) is the most common autoinflammatory disease. Without therapy, it may lead to the development of secondary amyloidosis. Treatment with colchicine leads to long-term remission in ~70% of patients. 5% are resistant to colchicine therapy (crFMF) and may be treated with monthly dose of canakinumab (anti IL-1beta). However, colchicine, the only drug proved to prevent secondary amyloidosis. Canakinumab is immunosuppressive as well as expensive. Therefore, we aimed to compare on demand canakinumab (COD) dosage policy vs. canakinumab fixed frequency (CFF) policy.

Methods: Data from 3 Israeli pediatric rheumatology centers (Schneider Children’s Medical Center of Israel, Sheba Tel-HaShomer Medical Center, Rambam Health Care Campus) were collected regarding crFMF patients treated with canakinumab. crFMF patients treated according to the COD policy were given 1 dose of sc-canakinumab injection 4mg/kg (max 150mg), with subsequent doses administered only after an additional attack. CFF patients were given fixed monthly doses according to the manufacturer instructions.

Results: Overall, 51 crFMF (25 COD vs. 26 FCC) with mean follow-up of 22.6 months were included. There were no significant demographic, clinical or genetic differences between the groups. The COD group received significantly lower cumulative canakinumab dosage during the follow-up period (15.688.95mg/kg vs.32.58.05mg/kg; P< 0.001). There were no differences between groups in mean FMF attacks nor in mean CRP levels at the end of follow-up period. None the less, the COD group necessitated higher colchicine doses (0.050.01mg/kg vs. 0.030.01mg/kg; P< 0.001). Overall, 51 crFMF (25 COD vs. 26 FCC) with mean follow-up of 22.6 months were included. There were no significant demographic, clinical or genetic differences between the groups. The COD group received significantly lower cumulative canakinumab dosage during the follow-up period (15.688.95mg/kg vs.32.58.05mg/kg; P< 0.001). There were no differences between groups in mean FMF attacks nor in mean CRP levels at the end of follow-up period. None the less, the COD group necessitated higher colchicine doses (0.050.01mg/kg vs. 0.030.01mg/kg; P< 0.001).

Conclusion: COD treatment in crFMF patients is as effective as CFF treatment. Using COD can reduce drug expenses and decrease immunosuppression exposure without negatively influencing the disease control.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/can-children-with-colchicine-resistant-fmf-be-treated-with-on-demand-canakinumab-regimen-a-multicenter-study/