For decades, a deadly childhood cancer has eluded the best tools of science. Now doctors have made strides with an unusual treatment: drip millions of copies of a virus directly into the brains of children to infect their tumors and encourage an attack by the immune system.
A dozen children treated in this way lived more than twice as long as comparable patients in the past, doctors reported Saturday at a conference of the American Association for Cancer Research and in the New England Journal of Medicine.
Although most of them eventually died of their disease, some are still alive for several years after treatment – something which is virtually unheard of in this situation.
“This is the first step, a critical step,” said study leader Dr. Gregory Friedman, a childhood cancer specialist at the University of Alabama at Birmingham.
“Our goal is to improve on this,” possibly by trying it when patients are first diagnosed or by combining it with other therapies to boost the immune system, he said. The patients in the study were given the experimental approach after failing other treatments.
The study involved gliomas, which make up 8% to 10% of brain tumors in children. They are usually treated with surgery, chemotherapy, or radiation, but they often come back. Once they do, the average survival is just under six months.
In such cases, the immune system has lost the ability to recognize and attack the cancer, so scientists have been looking for ways to turn the tumor into a new target. They turned to the herpes virus, which causes cold sores and stimulates a strong immune system response. Treovir, a suburban company in Philadelphia, developed a treatment by genetically modifying the virus so that it would only infect cancer cells.
By means of small tubes inserted into the tumors, doctors gave the altered virus to 12 patients, ages 7 to 18, whose cancer had worsened after usual treatments. Half also received a dose of radiation, which is believed to help spread the virus.
Eleven showed evidence in imaging tests or tissue samples that the treatment worked. Median survival was a little over a year, more than double what has been seen in the past. As of last June – the close for analyzing these results – four were still alive, at least 18 months after treatment.
Tests also showed high levels of specialized immune system cells in their tumors, suggesting that the treatment had recruited the body’s help to attack the disease.
No serious safety concerns were observed, although there were several procedure-related complications and mild side effects, including nausea, vomiting, diarrhea and fatigue.
Jake Kestler received the treatment when he was 12.
He lived another year and four months after that, “long enough to celebrate his bar mitzvah, take his family to Hawaii and see a brother born,” said his father, Josh Kestler, a financial services manager from Livingston, New Jersey.
Jake died on April 11, 2019, but “we don’t regret trying the treatment,” said Kestler, who has started a foundation with his wife, Trail Blazers for Kids, for further research.
“It’s a devastating disease for these patients and their families,” and initial results suggest the virus treatment is helping, but they need to be verified in a larger study, which doctors are planning, said Dr. Antoni Ribas, a cancer specialist at the University of London. California, Los Angeles, and chairman of the group organizing the conference.
Friedman said studies are continuing in adults as well, and plans are in the works for other types of brain tumors in children. US government grants and various foundations paid for the study, and several doctors have financial ties to Treovir.
Only one comparable virus therapy is currently approved in the United States – Imlygic, also a modified herpes virus, for the treatment of melanoma, the most serious form of skin cancer.
The Associated Press Department of Health and Science is supported by the Science Education Department of the Howard Hughes Medical Institute. The AP is solely responsible for all content.