Recombinant human interleukin-1 receptor antagonist in severe traumatic brain injury: a phase II randomized control trial

J Cereb Blood Flow Metab. 2014 May;34(5):845-51. doi: 10.1038/jcbfm.2014.23. Epub 2014 Feb 26.


Traumatic brain injury (TBI) is the commonest cause of death and disability in those aged under 40 years. Interleukin-1 receptor antagonist (IL1ra) is an endogenous competitive antagonist at the interleukin-1 type-1 receptor (IL-1R). Antagonism at the IL-1R confers neuroprotection in several rodent models of neuronal injury (i.e., trauma, stroke and excitotoxicity). We describe a single center, phase II, open label, randomized-control study of recombinant human IL1ra (rhIL1ra, anakinra) in severe TBI, at a dose of 100 mg subcutaneously once a day for 5 days in 20 patients randomized 1:1. We provide safety data (primary outcome) in this pathology, utilize cerebral microdialysis to directly determine brain extracellular concentrations of IL1ra and 41 cytokines and chemokines, and use principal component analysis (PCA) to explore the resultant cerebral cytokine profile. Interleukin-1 receptor antagonist was safe, penetrated into plasma and the brain extracellular fluid. The PCA showed a separation in cytokine profiles after IL1ra administration. A candidate cytokine from this analysis, macrophage-derived chemoattractant, was significantly lower in the rhIL1ra-treated group. Our results provide promising data for rhIL1ra as a therapeutic candidate by showing safety, brain penetration and a modification of the neuroinflammatory response to TBI by a putative neuroprotective agent in humans for the first time.

Publication types

  • Clinical Trial, Phase II
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Brain / drug effects*
  • Brain / immunology
  • Brain / pathology
  • Brain Injuries / drug therapy*
  • Brain Injuries / immunology
  • Brain Injuries / pathology
  • Cytokines / analysis
  • Cytokines / immunology
  • Female
  • Humans
  • Interleukin 1 Receptor Antagonist Protein / administration & dosage
  • Interleukin 1 Receptor Antagonist Protein / adverse effects
  • Interleukin 1 Receptor Antagonist Protein / therapeutic use*
  • Male
  • Middle Aged
  • Receptors, Interleukin-1 / antagonists & inhibitors*
  • Receptors, Interleukin-1 / immunology
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / adverse effects
  • Recombinant Proteins / therapeutic use
  • Young Adult


  • Cytokines
  • Interleukin 1 Receptor Antagonist Protein
  • Receptors, Interleukin-1
  • Recombinant Proteins