IL13-PE38 is a fusion protein that combines interleukin-13 (IL-13) with a truncated form of Pseudomonas exotoxin A (PE38). This engineered molecule is designed to target and kill cancer cells, especially those that express the IL-13 alpha-2 receptor (IL-13R), which is often found in higher amounts on certain tumor cells, such as glioblastomas and other cancers.

Here’s how IL13-PE38 works:

Targeting: IL-13 binds to the IL-13 receptor on the surface of cancer cells.

Delivery: Once bound, the molecule is taken into the cancer cell.

Toxin Release: The PE38 portion of the fusion protein is delivered inside the cell, where it inhibits protein synthesis by inactivating elongation factor 2 (EF-2), leading to cell death, independent of cell cycle or hypoxia.

This fusion protein has been investigated for targeted cancer therapies, leveraging the fact that glioblastoma (GBM) stem cells overexpress IL-13 alpha-2 receptors, which are absent on normal brain cells. This selective expression allows the treatment to precisely attack cancer cells while minimizing damage to healthy, normal brain tissue.