Single dose of G207 infused through catheters into region(s) of tumor. If G207 is safe in the first cohort of patients, subsequent patients will receive a single dose of G207 infused through catheters into region(s) of tumor followed by a 5 Gy dose of radiation to the tumor (which includes progressive leptomeningeal disease or any site of gross tumor progressing in the brain parenchyma) within 24 hours of virus inoculation.
Outcomes for children with recurrent or progressive cerebellar malignant brain tumors are very poor, and there are a lack of effective salvage therapies once a patient fails standard treatments. G207 is an oncolytic herpes simplex virus-1 (HSV) that has been successfully engineered to introduce mutations in the virus that enable it to selectively replicate in and kill cancer cells, but not normal cells.
Replication of G207 in the tumor not only kills the infected tumor cells, but causes the tumor cell to act as a factory to produce new virus. These virus particles are released as the tumor cell dies, and can then proceed to infect other tumor cells in the vicinity, and continue the process of tumor kill.