Real-world efficacy, safety, and drug retention of anakinra and canakinumab in paediatric colchicine-resistant familial Mediterranean fever: Insights from a single-centre cohort

BACKGROUND: This study evaluated the efficacy, safety, and drug retention of anakinra and canakinumab in paediatric patients with colchicine-resistant familial Mediterranean fever (cr-FMF) within a real-world cohort. METHODS: This retrospective cohort study was conducted from June 2016 to April 2024, including 86 patients diagnosed with cr-FMF. Clinical and laboratory parameters, including attack frequency, C-reactive protein, serum amyloid A, and autoinflammatory disease activity index (AIDAI) scores, were recorded at baseline and during follow-up. RESULTS: A total of 86 patients (50 females, 36 males) were included in the study. All carried exon 10 MEFV mutations, with 69 patients (80.2%) having the M694V/M694V genotype. Anakinra was initiated in 36 patients (41.9%), and canakinumab in 50 patients (58.1%). The median treatment duration was significantly longer for canakinumab (48 months) compared to anakinra (7 months) (P < .001). Both treatments significantly reduced attack frequency, AIDAI scores, C-reactive protein, and serum amyloid A levels compared to baseline (P < .001). While the reduction in attack frequency was comparable between the groups, patients treated with canakinumab achieved significantly lower mean AIDAI scores at 12 months compared to the anakinra group (P = .021). Anakinra provided a more rapid onset of symptom control but was commonly discontinued due to injection site reactions (44.4%). Canakinumab was associated with sustained long-term disease control with fewer local side effects. However, rare serious events, including acute myeloid leukaemia and inflammatory bowel disease, were observed, though causality with treatment could not be established. CONCLUSIONS: In this paediatric cohort of cr-FMF patients, both anakinra and canakinumab were effective in reducing disease activity and inflammation. Anakinra offered rapid symptom relief but had frequent injection site reactions. Canakinumab provided sustained control with fewer local side effects but required monitoring for rare complications.