PAC-1, an experimental anti-cancer drug, has been approved by the FDA for use in clinical trials. The drug will be tested on patients with glioblastoma multiforme, an aggressive and lethal form of brain cancer. It will also be tested on patients with anaplastic astrocytoma, a rare malignant form of brain tumour.
The median survival time for patients with glioblastoma undergoing the standard treatment is about 15 months. This dismal prognosis is attributed to the fact that glioblastoma has the ability to spread along the blood vessels in the brain and cannot be removed through surgery, making it essential for further research into this tumour type to be conducted.
PAC-1 works by activating a specific protein called procaspase-3, which has the ability to kill cells. The level of this particular protein is elevated in cancer cells, allowing the drug to target only cancerous cells over healthy cells.
In addition, PAC-1 has the ability to cross the blood brain barrier in sufficient quantities. The blood brain barrier is a cluster of cells that protects the brain from harmful substances. So the ability to cross this barrier is a difficult feat to accomplish for many of the anti-cancer drugs.
This phase 1(b) trial is going to evaluate the safety and efficacy of using PAC-1 in combination with temozolomide. While phase 1 trials are designed to evaluate the safety a new drug in people, this particular trial is an extension of an ongoing phase 1(a) trial which is testing the safety of only PAC-1.
The researchers from University of Illinois—Professor Paul Hergenrother and Dr Timothy Fan—have reported positive results from pre-clinical trials assessing the combination treatment.
“PAC-I has the best opportunity to improve when used with other drugs," said Dr Fan. “It is not likely that temozolomide is the only drug that it can be used with."
While it could take a few years of clinical trials before this combination treatment becomes widely available, this research could have a significant clinical impact on individuals with a brain tumour. This new research aims to provide these patients with new treatments that could increase their overall survival.