Research on Virus-gene Therapy for Melanoma Shows Promise

Researchers at the University of California San Diego Moores Cancer Center are conducting an international phase III trial to examine the effect that a modified herpes virus has on melanoma tumors.

Gregory Daniels, MD, PhD, assistant clinical professor of medicine at the UC San Diego School of Medicine, and coworkers “are comparing the modified virus treatment, called OncoVEX GM-CSF, to general immune system stimulation with the immune-boosting protein GM-CSF” in patients with advanced melanoma. Early testing has shown that about 26% of patients treated with OncoVEX GM-CSF therapy demonstrated a “partial or complete response,” where “cancers either stopped growing or regressed.”

Daniels explained that the injected virus has “preferentially” infected cancer cells, leading to tumor death, and has possibly directed an immune response to tumors that were and were not injected with the herpes virus. This change to the immune system has also, on occasion, shrunk un-injected tumors, according to Daniels. “It’s a more active type of immunotherapy, causing a cascade of immune system activity in the body,” he added.

The researchers are looking to enroll 30 patients with advanced melanoma in the trial, patients whose cancer cannot be surgically removed and who have failed one prior therapy. According to the researchers, “the goal of the trial is not necessarily to cure the patients of their cancer, but to enable them to live disease-free for at least six months and longer.” In the end, 360 patients worldwide will have enrolled in the trial, with twice as many patients receiving OncoVEX GM-CSF as GM-CSF.

According to Daniels, the “virus infection-immune system-boosting approach” could also be used one day to treat other types of cancer, such as colon, breast, prostate, bladder and lung, in addition to melanoma.

“Melanoma has always been curable, but only in a small fraction of patients,” Daniels said. “Local tumor killing with immune activation may provide an additional tool to increase this number to a larger population of cancer patients.”