The Eurofever FMF longitudinal cohort: first update on the longitudinal data

Objective: In 2021 we described the baseline clinical information about 887 Familial Mediterranean Fever (FMF) patients enrolled in the Eurofever registry since 2009 [1]. We describe now the first longitudinal data related to this cohort. Methods: Patients with FMF enrolled in Eurofever registry with at least one follow-up visit were included in a retrospective study. From 2022 data on compliance and quality of life were also available. Response to treatment was evaluated as i) complete response (no disease flare and negative acute phase reactants), ii) partial response (reduction of at least 50% of episodes from baseline); iii) unsatisfactory or no response (persistence of fever episode and/or persistent elevation of acute phase reactants within the episodes). Colchicine resistance was defined according to the recent guidelines [2]. Results: Follow-up information was available in 443 patients (256 males and 197 females, 319 children and 124 adults) from … centers from … countries. The median age at disease onset was 4.1 years (range 0.5 – 27.9); the median diagnostic delay was 3.0 (range 0.3 – 29.9); the median age at enrollment was 9.4 (range 2.1 – 52.3). The median duration of follow-up after enrollment was 4.3 years (range 0.5 – 12.8). Mean number of follow-up visits was 2.0 (5-95th centile 1-6), 87 patients received more than one follow-up visits. At last follow-up 44.5% of patients was on complete remission, 33.6% was on partial remission and 21.9% was non responders, presenting an active disease. 420 patients (95 %) received colchicine during their disease course, among them 372 patients (88.6%) were still receiving colchicine at the last follow-up. Twenty-one patients (4.8%) were treated with anakinra, and 2 of them were still receiving the drug at last follow-up. 42 patients (9.5%) received canakinumab during their disease course with 39 of them (92.2%) still receiving the drug at the last follow-up. 31 patients were on combined treatment with colchicine and anti-IL1. 10 patients received treatments other than colchicine and anti-IL1 (sulfasalazine, adalimumab, thalidomide, methotrexate, etanercept, infliximab, golimumab). From 2022, data on compliance and quality of life were also available. We collected data on compliance of 55 patients (49 with colchicine and 6 with canakinumab). An optimal compliance (> 95% of prescriptions) was reported in 43 patients (80%), a good compliance (from 50 to 95 % of prescriptions) in 14 patients and a poor compliance (less than 50% of prescription) in 2 patients in colchicine. Conclusions: herein we present the first longitudinal data on the Eurofever FMF cohort study. An ongoing disease activity is observed in around 55% of the patients. A growing number of patients in anti-IL-1 treatment is observed, reaching the 9.5% of the whole cohort. Data on safely are longitudinally collected.