Transport study of interleukin-1 inhibitors using a human in vitro model of the blood-brain barrier

The proinflammatory cytokine Interleukin-1 (IL-1), with its two isoforms α and β, has important roles in multiple pathogenic processes in the central nervous system. The present study aimed to evaluate and compare the blood-to-brain distribution of anakinra (IL-1 receptor antagonist), bermekimab (IL-1α antagonist) and canakinumab (IL-1β antagonist). A human in vitro model of the blood-brain barrier derived from human umbilical cord blood stem cells was used, where isolated CD34(+) cells co-cultured with bovine pericytes were matured into polarized brain-like endothelial cells. Transport rates of the three test items were evaluated after 180 ​min incubation at concentrations 50, 250 and 1250 ​nM in a transwell system. We report herein that anakinra passes the human brain-like endothelial monolayer at a 4-7-fold higher rate than the monoclonal antibodies tested. Both antibodies had similar transport rates at all concentrations. No dose-dependent effects in transport rates were observed, nor any saturation effects at supraphysiological concentrations. The larger propensity of anakinra to pass this model of the human blood-brain barrier supports existing data and confirms that anakinra can reach the brain compartment at clinically relevant concentrations. As anakinra inhibits the actions of both IL-1α and IL-1β, it blocks all effects of IL-1 downstream signaling. The results herein further add to the growing body of evidence of the potential utility of anakinra to treat neuroinflammatory disorders.