Long-term effectiveness and safety of canakinumab in pediatric familial Mediterranean fever patients.

Background: Little is known about the long-term efficacy and safety of canakinumab in paediatric FMF patients. Aim: To present the single centre experience of colchicine-resistant paediatric-onset FMF patients who were treated with canakinumab by off-label use since 2012. Methods: The hospital files of 15 children who used canakinumab were retrospectively evaluated. Clinical and laboratory data of each visit were recorded. Drug-related adverse events were recorded. Complete remission was described as no attacks and normal acute phase reactants; partial remission was defined as decrease in severity and rate of attacks and/or elevated acute phase reactants with anti-IL-1 treatment. Results: The average duration of canakinumab use was 23.9 months (min:12, max:58 months). Twelve patients were M694V homozygotes. Eleven patients achieved complete remission after the first dose at 2 months and 12 patients at 6 months. Canakinumab interval was shortened in 2 patients from 150 mg/8 weeks to 150 mg/4 weeks. Except one, 14 patients achieved complete remission by 12 months. Two patients had mild urinary tract infections. One patient had bronchopneumonia requiring hospitalization. Two patients had teeth abscess. There were no serious adverse events such as opportunistic infections, malignancies, or deaths. Besides, no significant laboratory abnormalities occurred in complete blood count parameters, liver and kidney function tests. Conclusion: To the best of our knowledge, this is the longest outcome study about canakinumab use in paediatric FMF patients. This study suggested that canakinumab is safe and effective in children with FMF in the long term.