A recent study on patients suffering from deadly brain cancer suggest that a genetically-engineered cold virus may be able to attack tumor cells and significantly extend the life span of some patients with glioblastoma, a deadly brain cancer the Houston Chronicle reports. The findings provide yet another promising sign for new, experimental cancer immunotherapies.

Conducted by researchers at Houston’s MD Anderson Cancer Center, the research represents the first published evidence that experimental viral immunotherapy may benefit select patients following the return of glioblastoma, one of the deadliest and most aggressive forms of brain cancer.

The results, published in the Journal of Clinical Oncology, showed that a cold virus engineered to infect cancer cells could effectively destroy tumors after as little as one injection. The study also showed that the virus triggered an immune response against the cancer in certain patients, while causing minimal side effects.

Historically, glioblastoma is one of the cancers least likely to respond to immunotherapy. Typically, patients live an average of six months after cancer recurrence. However, after receiving the experimental treatment, researchers said five of 25 patients in the trial lived three to five years after their cancer recurred.

“This opens up a potential therapy for a disease that has no good treatment,” said Frederick Lang, MD, Anderson’s chairman of neurosurgery and the study’s lead author. “And it does it with a natural virus that works in a unique way.”

Though researchers say the findings will need to be replicated in a much larger group of patients, the new treatment and its ability to extend the life span of nearly 20 percent of subjects have been called “very important.”

For more information about the landmark immunotherapy study, click here.