Brain Cancer treatment shows promise in early trial

An experimental viral treatment may extend the lives of patients with a hard-to-treat brain cancer, researchers say.
For the phase 1 study, patients with recurrent glioblastoma, the most common and aggressive brain tumor, were injected with an engineered virus.
Survival was 13.6 months among 43 patients treated with the viral therapy, compared with 7.1 months for patients who did not receive the new therapy, according to the study.
"For the first time, this clinical data shows that this treatment, used in combination with an antifungal drug, kills cancer cells and appears to activate the immune system against them while sparing healthy cells," said study co-leader Dr. Timothy Cloughesy. He is director of the neuro-oncology program at the University of California, Los Angeles.
"This approach also has potential in additional types of the disease, such as metastatic colorectal and breast cancers."
Here's how the treatment works: Injectable Toca 511 infects actively dividing cancer cells and delivers a gene for an enzyme called cytosine deaminase to the cancer cells. Inside the tumor, Toca 511 programs the cancer cells to make cytosine deaminase to set them up for the second step of the treatment.
In that next phase, the patient takes the antifungal drug Toca FC. The genetic changes triggered by Toca 511 cause the cancer cells to convert Toca FC into the anticancer drug 5-fluorouracil (5-FU).
This leads to the targeted death of infected cancer cells and cells that help tumors hide from the immune system, while leaving healthy cells unharmed, the researchers explained.
These are the first published clinical trial results of this new type of modified virus known as a retroviral replicating vector (RRV)