CINCINNATI Scientists have used a genetically reprogrammed herpes virus and an anti-vascular drug to shrink spreading distant sarcomas designed to model metastatic disease in mice still an elusive goal when treating humans with cancer, according to a study in the July 8 Gene Therapy.
Less than 30 percent of patients with metastatic cancer survive beyond five years, despite the aggressive use of modern combination therapies, including chemotherapy. This creates a significant need for new sarcoma therapies to treat metastatic disease, said Timothy Cripe, M.D., Ph.D., a physician/researcher in the division of Hematology/Oncology at Cincinnati Children's Hospital Medical Center and the study's senior investigator.
The study results are even more significant because the oncolytic herpes virus, HSV-rRp450, was given to the mice systemically to attack tumors via the blood stream instead of being injected directly into tumors.
"Systemic bio-distribution has been a major stumbling block for using virus vectors in gene transfer and virotherapy to treat cancer, but we show that viruses can be used systemically by giving them intravenously to get an anti-tumor effect," Dr. Cripe said.
Also important to results of the current study was using the virus in conjunction with a drug (bevacizumab) that blocks the growth of tumor feeding-blood vessels. In the current study, researchers focused on spreading Ewing sarcoma and Rhabdomyosarcoma cancers that form in muscle, bone and connective tissue.
Anti-angiogenic agents like bevacizumab are usually given first in combination cancer therapies because they help enlarge intercellular openings to tumor cells and ease the delivery of drugs, such as chemotherapies. In this study, however, the researchers discovered that bevacizumab has to be given after the virus to maximize the anti-tumor effect of the combined therapy. In fact, giving bevacizumab first lowered the virus's up
|Contact: Nick Miller|
Cincinnati Children's Hospital Medical Center