Useful tumor-targeting drugs select tumor cells while ignoring healthy ones, destroying tumor cells without damaging the adjacent healthy brain tissue.

NeoPharm uses a recombinant protein Cintredekin Besudotox (IL13-PE38QQR) consisting of a single molecule composed of two parts: a tumor-targeting molecule (IL13) and a cytotoxic agent (PE38). IL13 receptors are found on malignant glioma cells, but not to any measurable degree, if at all, on healthy brain cells.

Cintredekin Besudotox is designed to bind to IL13 receptors on the tumor like a key fits in a lock. The cancer cell latches onto and absorbs the IL13 and the attached PE38. As a result, the cancer cell dies. Healthy brain cells are expected to be unharmed because they do not have the IL13 receptors, and thus do not ingest the PE38.