Background:The pro-inflammatory cytokine interleukin (IL)-1 has a central role in the pathogenesis of adult-onset Still’s disease (AOSD), a rare auto-inflammatory condition. Anakinra, has been for years the cornerstone of IL-1-blocking therapy in AOSD. More recently, the monoclonal antibody canakinumab, a new agent blocking IL-1, has become availableObjectives:To describe our real-life experience with CNK in a cohort of AOSD patients from a single Italian CenterMethods:AOSD patients diagnosed according to Yamaguchi’s criteria followed-up at our Autoinflammatory Unit and treated with CNK for at least 3 months were included. Demographic features, disease characteristics, reasons for CNK introduction, concomitant therapies, variation in systemic steroids dose, adverse events, and response to treatment were retrospectively evaluated. Non-parametric tests were used for statistical comparisonResults:13 patients (5 women; median age 49 years, range 21-74), treated with subcutaneous CNK 4 mg/kg 4-weekly, were identified. Median disease duration before CNK introduction was 12 (6-240) months. After CNK introduction, 2 patients were followed-up for 18 months, 3 for 12 months, 6 for 6 months, 2 for 3 months. CNK was introduced as first-line biologic DMARD in 6 patients. The other 7 patients had been already treated with at least one other bDMARD, for a total of 15 treatment courses (7, anakinra, ANK; 4, tocilizumab; 4, TNF-inhibitors), with a median bDMARD therapy duration of 8 (4-178) months. Previous bDMARDs had been interrupted because of inefficacy (8 cases) or adverse events (AE, 7 cases); of the 7 ANK-treated patients, therapy interruption was due to inefficacy in 3 cases. At CNK introduction, 11 patients were on systemic steroid therapy, prednisone (PDN) equivalent dose 15 (5-80) mg, and 10 were concomitantly receiving a conventional DMARD (7, methotrexate; 2, colchicine; 1, cyclosporine-A).Graphic 1summarizes main clinical features at CNK introduction. After CNK start, a striking and rapid clinical response was observed, as demonstrated by a substantial decrease of modified Pouchot score and a normalization of acute phase reactants after only 3 months (see Table 1 for details). CNK showed also a significant steroid-sparing effect: median PDN dose was reduced to 7.5 (2.5-12.5) mg at month 3 and 5 (0-7.5) mg at month 6; PDN was stopped in 3 patients (1 at month 3, 1 at month 6, 1 at month 12) due to optimal disease control. CNK was temporarily held-off in 3 patients (zoster reactivation, 1; prostatitis, 1; mild leukopenia, 1). We observed no case of primary inefficacyTable 1.Disease activity and blood tests at canakinumab introduction and during follow-upDaily prednisone dosemgBaseline(n=13)3 months(n=13)6 months(n=11)12 months(n=5)18 months(n=2)Pouchot score15 (5-80)7.5 (2.5-12.5)5 (0-7.5)5 (0-7.5)2.5VAS pain3 (2-5)1 (0-2)0 (0-1)00Erythrocyte sedimentation ratemm/h7 (2-10)3 (1-8)2 (1-4)1 (1-2)1C-reactive proteinmg/L42 (8-120)21 (2-69)13 (2-55)14 (2-41)11Ferritinng/mL20.8 (3-180)3.1 (0.5-22.5)1.6 (0.5-8.4)1 (0.3-6.3)0.5Hemoglobing/dL379.5 (161-914)282 (82-552)215 (34-464)177 (77-401)19913.1 (9.4-15.7)13.2 (10.7-15.3)13.8 (11.5-15.5)13.9 (11.3-14.3)13.5Figure 1.Graphic 1 Main clinical features at canakinumab introductionConclusion:Our real-life data confirm that CNK is highly effective and safe in AOSD treatment and has significant steroid-sparing effects. CNK showed its efficacy both as first-line therapy and after other bDMARDs failure, also in patients who have previously failed IL-1 inhibition through ANK