Targeting Tumor Cells
The tumor cell-surface receptor being targeted does not need to be unique to tumor cells since the bispecific antibody-targeted, payload-packaged EDV™ nanocells only exit the leaky blood vessels associated with tumors (passive targeting) and enter the tumor microenvironment. The EDV™ is 400nm ± 20nm which is too large to escape through the normal vasculature associated with normal tissues including the gut, liver and skin. This allows us to target the EDVs™ to a protein receptor such as the ubiquitous Epidermal Growth Factor Receptor (EGFR) which is over-expressed in 70% of solid tumors but are also expressed on normal cells. The EDVs™ are simply too large to extravasate into normal tissue and no toxicity to normal tissues has been observed in animal and human studies, despite targeting the EDVs™ to EGFR.
In the tumor microenvironment, the bispecific antibody binds to the tumor cell-surface receptor (active targeting). Once bound to the tumor cell, the EDV™ is taken up by a process called macropinocytosis. It is broken down within the cancer cell and releases its payload of chemotherapeutic drug or siRNA or miRNA. The payload is only released inside the cancer cell, resulting in a more potent and far less toxic chemotherapy.