Longterm Beneficial Effect of Canakinumab in Colchicine-resistant Familial Mediterranean Fever.

Objective: To assess the efficacy and safety of the interleukin-1β (IL-1β) inhibitor canakinumab in all adolescent and adult patients with familial Mediterranean fever (FMF) identified from the Greek National Registry for off-label drug use between 2010 and 2015.

Methods: In this retrospective longitudinal outcome study, clinical and laboratory data were collected from 14 patients (7 men) aged median 38.5 years (range 13-70), with median disease duration of 14 years, and active FMF despite colchicine (n = 9) or both colchicine and anakinra (n = 5).

Results: All patients continued to receive canakinumab at last visit (median of 18 mos, range 13-53), which was initially given as monotherapy (n = 8) or in combination with colchicine and/or corticosteroids, every 4 (n = 7), 6 (n = 2), or 8 weeks (n = 5). Eleven patients (79%), including 6 receiving monotherapy, achieved complete clinical remission within 2 months (median), while normalization of all laboratory variables denoting inflammation occurred in 92% at 3 months (median). The remaining 3 patients achieved partial responses. Responses were sustained in all but 4 patients, who relapsed. Reducing the canakinumab administration interval from 8 or 6 weeks to 4 weeks led to suppression of disease activity in the relapsing patients. On the other hand, drug administration interval could be safely increased in 2 patients in remission. Corticosteroid doses were significantly reduced during followup. Canakinumab was well tolerated; 1 patient experienced a urinary tract infection and another one a viral gastroenteritis.

Conclusion: Treatment with canakinumab in an individualized dosing scheme results in rapid and sustained remission in colchicine-resistant FMF.