Results from a phase 1 clinical trial, testing a drug called CLR 124, demonstrates its ability to cross the blood-brain barrier
The blood-brain barrier refers to the tightly-packed cells that line the walls of the blood vessels in the brain. These cells allow only lets some substances, such as water, oxygen, carbon dioxide, and essential nutrients to pass through.
While this protective barrier blocks harmful substances from reaching the brain, it also prevents the entry of many drugs. This presents a substantial challenge when developing drugs that target brain tumours.
A PDC is a type of drug that is engineered to target cancer cells by attaching to specific proteins present on the cell. These proteins are more abundant in cancer cells than normal cells, which results in the drug selectively targeting cancer cells. This allows for more potent drug delivery and reduces the harm to surrounding normal cells.
The study demonstrated that CLR 124 has the ability to cross the blood-brain barrier in sufficient quantities and target the tumour. The results of this study are significant because the structure of CLR 124 is comparable to another drug called CLR 131.
As suggested by its name, CLR 124 delivers iodine 124—an isotope of iodine used for diagnostic purposes—to the tumour. In comparison, CLR 131 delivers a therapeutic form of iodine, iodine 131, which is toxic to cells.
“We plan to initiate a Phase 1 pediatric study in cancers including pediatric high-grade gliomas and malignant brain tumors in the near future," said James Caruso, chief executive officer of Cellectar Biosciences.
If successful in the aforementioned clinical studies, these drugs would have a significant impact on the management of brain tumours, as they would improve diagnosis, as well as treatment.