Background IL-1 pathway plays a major role in the pathogenesis of Adult onset Still's disease (AOSD). IL-1 inhibitors [Anakinra (ANK) and Canakinumab (CAN)] proved their efficacy in AOSD as demonstrated in several case-reports and small case-series. However, due to the disease rarity, large randomized control trials are still lacking.
Objectives To retrospectively evaluate the efficacy and safety of the use of IL-1 inhibitors (ANK and CAN) in patients with AOSD.
Methods Data from patients with diagnosis of AOSD (Yamaguchi criteria) referred by 18 different Italian centres were retrospectively collected. Clinical and serological features as well as concomitant treatments, were collected on a dedicated database at the beginning of anti-IL-1 treatment (baseline) and then after 3, 6 and 12 months of follow-up. The Pouchot's score was used to evaluate disease activity.
Results Data from 140 patients were collected (Table). All were treated with ANK and 4 were subsequently switched to CAN after ANK failure. The systemic pattern vs the chronic-articular were present in ANK and CAN groups in 104/140 (74.2%) and 3/4 (75%), respectively, vs 48/140 (25.8%) and 1/4 (25%), respectively. MTX was the most commonly used DMARD before ANK or CAN [91/140 (75.8%), 2/4 (50%) respectively]. In ANK group, the most commonly used previous biologic drug (bDMARD) was etanercept (79.3%). ANK was adopted as second-line bDMARD in 29/140 (20.7%) patients. In most of the cases it was administered at 100 mg/day in 126/140 patients (90%). CAN was employed at 150 mg every 8 weeks. ANK was effective on all AOSD clinical (fever, rash, pneumonia, pericarditis, pleuritis, sorethroat, lymphadenopathy, hepatomegaly, myalgia, arthritis, MAS) and serological (increased liver enzymes, hyperferritinemia, leucocytosis) manifestations (p<0.0001). The Pouchot's score was significantly reduced at all time points (p<0.0001). In ANK group no difference in treatment response was identified stratifying patients according to age, sex, pattern of disease, monotherapy vs combination. ANK primary and secondary inefficacy after 12 months were 15/140 (10.7%) and 11/140 (7.8%) cases, respectively. Adverse events (AEs) [mainly represented by in situ (28/47, 59.5%) or diffused (12/47, 25.5%) skin reactions and infections (12/47, 12.7%)] were the main reason for ANK discontinuation. Similarly, in CAN group Pouchot's score and clinical and serological features significantly ameliorated at all time points (p<0.0001). No AEs occurred with CAN, only in one case (1/4, 25%) treatment was stopped for loss of efficacy.
Conclusions To our knowledge this is the largest retrospective observational study evaluating the efficacy and safety of ANK and CAN in AOSD. A prompt response was demonstrated already at 3 months of follow-up both in ANK and CAN groups. ANK proved to be effective in both patterns of disease, appearing also safe on the infectious risk. Nonetheless, skin reaction may represent a not negligible AEs during ANK treatment.
Disclosure of Interest None declared