Abstract: 1282: Preliminary Evidence for Sustained Bioactivity of IL-1 Trap (Rilonacept), A Long Acting IL-1 Inhibitor, In Systemic Juvenile Idiopathic Arthritis (SJIA)
Sangeeta Sule, M.D.
Authors:
D. J. Lovell, E. H. Giannini, Y. Kimura, S. Li, P. J. Hashkes, A. O. Reiff, C. A. Wallace, K. B. Onel, Y. Wei, W. Fury, D. R. Nadler, S. Biedermann, G. Osgood, J. H. Papadopoulos, A. R. Radin
Background:
Interleukin-1 (IL-1) is thought to play an important role in systemic onset JIA. Inhibition of IL-1 with short-acting medications (anakinra) has shown some clinical benefit. This abstract reports on the role of rilonacept, a long-acting soluble receptor based IL-1 blocker.
Methods:
21 children with systemic onset JIA were enrolled, age 5-20 years, mean disease duration of 3.1 years. Patients received either 2.2 or 4.4 mg/kg IL-1 Trap or placebo SC once weekly for 4 weeks in the double-blind phase. Open label treatment at the allocated dose occurred after 4 weeks in the double-blind study or after 2 weeks, if rescue in the double-blind study was warranted. The study is ongoing.
Results:
21 subjects with open label data are reported. Improvement in all ACR Ped core variables was noted with ACR Ped 30 of 76.2%, ACR Ped 50 of 61.9%, ACR Ped 70 of 33.3% after 4 weeks. For 12 subjects who remain in the study with a median of 42 weeks open label treatment, ACR Ped 50/70 increased to 83.3%. All subjects with fever and/or rash at baseline had resolution of these symptoms. WBC, platelet, and hemoglobin counts improved while d-dimer and ferritin levels decreased.
Conclusions:
In this open-label data report of 21 children receiving 2.2 and 4.4 mg/kg/week IL-1 Trap, there was improvement noted in inflammatory markers and clinical status.
Editorial:
This study reports preliminary data from an ongoing double-blind study of IL-1 Trap in the treatment of systemic onset JIA. Anakinra, an IL-1 antagonist, has also been shown to be effective in systemic onset JIA. However, anakinra injections are once a day as opposed to the IL-1 Trap injections given once a week. This is an important difference, particularly in the pediatric population. The results from this abstract are impressive in that there was marked improvement in ACR Ped scores with complete resolution of fever and rash. However, these results are very preliminary and we await the results from the double-blind portion of the study. The safety of long-term IL-suppression in children needs further evaluation.
