For the last century or so, the medical community has been aware that viruses can have a destructive effect on cancer. This became evident when some cancer patients went into remission (if only temporarily) after having a viral infection. Since then, researchers have been trying to harness the potential that these otherwise undesirable bugs may have in the fight against some of the deadliest cancers.
Leading the pack is Dr. Matthias Gromeier, whose use of the polio virus to treat the deadliest form of brain cancer, has been called nothing short of one of the most exciting developments ever to occur in cancer research. Earlier this year, Gromeier and his colleagues published the results of a Phase I clinical trial in the New England Journal of Medicine. Dr. Gromeier, Professor of Neurosurgery at Duke University, and his team used a genetically modified version of the poliovirus to treat patients with recurrent glioblastoma multeforme, (GBM) the deadliest type of brain cancer. In the engineered version, a portion of the paralyzing poliovirus’ DNA has been replaced by a portion of DNA from the rhinovirus (common cold virus) to prevent it from causing a polio infection. The hybrid virus is then placed directly into the brain via a catheter, where it not only kills malignant cells directly, but stimulates an immune response as well.
Receiving a diagnosis of GBM is nearly always a death sentence, with fifteen thousand adults dying annually. The average life expectancy is somewhere between fifteen and twenty months with the standard treatments (surgery, radiation and chemotherapy). Unfortunately, brain cancers are notoriously difficult to treat because of their location and cell heterogeneity. There is almost always a recurrence of the disease.
The results of the trial are stunning. The sixty-one patients who were in the trial had an overall average survival time of 12.5 months, compared to 11.3 months after the standard treatment. Even more astonishing is that twenty-one percent of the group is alive three years later (compared to four percent treated by standard therapies) and two people have lived for nearly six years! With a disease as aggressive and deadly as GBM, these are astonishing outcomes. The FDA has granted “breakthrough” status to this therapy, which allows its officials to accelerate the review process.
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Other recent milestones in oncolytic therapies:
- In 2015, the FDA approved the first oncologic viral therapy to treat some patients with metastatic melanoma that cannot be surgically removed.
- A study published earlier this year showed that a member of the reovirus family, when injected into the bloodstream of a GBM patient, can cross the blood-brain barrier and reach the tumor.
- In a study that was published this month, researchers successfully deployed a ZIKA virus vaccine to target GBM cells that had been transplanted into mice.
- Earlier this year, researchers at the University of Alabama at Birmingham treated a small group of pediatric GBM patients with a modified herpes virus and most of the patients’ tumors have responded.