Brain uptake of therapeutic antibodies and recombinant enzymes is severely limited by their size. For example, the concentration of most therapeutic antibodies in the brain is only 0.1% of the concentration in the blood. We are developing proprietary platform technologies to actively transport these molecules across the BBB through receptor-mediated transcytosis (RMT). RMT through the BBB is the process by which macromolecules in the blood bind to receptors on the endothelial cells that make up the BBB and are actively transported and released into the brain.
Our large molecule transport vehicle (TV), platform technology engineers BBB receptor binding into an Fc domain. We have selected transferrin receptor (TfR), which is a highly-expressed BBB receptor that we believe has the ability to substantially improve brain uptake of therapeutic molecules. This construct can be integrated and fused to therapeutic molecules as described below, without disrupting the binding of transferrin to TfR.