However, the Biovex scientists went one step further when they inserted into the virus the gene for a powerful antitumor immunity stimulant called GM-CSF, (granulocyte macrophage colon stimulating factor). Its job is to induce an immune response to any surviving cancer cells released during the initial viral attack, essentially preventing the spread of these cells to other parts of the body.
"This aims to treat metastatic disease and reduce tumor recurrence," said Robert Coffin, Ph.D., chief scientific officer at Biovex Ltd. While this has not been demonstrated in patients, the approach has show promise in pre-clinical studies.
In a phase I/II clinical trial, the scientists tested their modified virus in 26 patients, including eight with melanoma, 13 with breast, three with head and neck cancer, and two with colorectal cancer. Each patient, all in the later stages of their disease, received either a single injection of the virus, the volume depending on tumor size, or in later stages of the clinical trial, three injections separated by two to three weeks.
Aside from evidence of tumor necrosis, the scientists detected expression of GM-CSF in injected tumors.
"There were no obvious differences in the effects on the different tumor types," added Hu. "Following the promising data, this version of OncoVEX is now entering Phase II development in a number of tumor types."
The study's principal investigator was Charles Coombes, M.D., Ph.D., who heads the Cancer Research (UK) Laboratories and a professor at Hammersmith Hospital, part of Imperial College, where many of the patients in the study were enrolled.
Engineered Measles Virus Seeks Out and Destroys Liver Cancer Cells: Abstract LB-297
A weakened measles virus, modified with a protein that normally takes up iodine in the thyroid gland, is being studied to treat human liver cancer cells grafted in an animal model.
Source:American Association for Cancer Research