A research trial finds a woman’s brain tumour shrinking after poliovirus injection.
THE same virus that causes paralysis and sometimes death in polio patients may have the potential to cure people with cancerous brain tumors based on early results of a research trial underway at Duke University Medical Center.
Stephanie Lipscomb, 22, learned that she was nearly cancer-free during a check-up at Duke Cancer Center on Monday – 14 months after a modified version of the poliovirus was injected into her brain to treat a recurring, aggressive cancer known as glioblastoma.
“I’m really pleased; the nodule is almost all gone,” neuro-oncologist Annick Desjardins told Lipscomb, as she examined the young woman’s MRI brain scan.
Lipscomb became the first patient to enter the first phase of testing for the poliovirus-based therapy when she was given the virus through a catheter inserted into her brain in May 2012.
“The fact that this patient had the procedure 14 months ago and there’s been no regrowth of the tumour is very, very exciting and promising,” said Desjardins, lead investigator in the study.
So far, seven patients have been treated in the poliovirus study.
Two who joined the project shortly after Lipscomb also have experienced dramatic shrinkage of their tumours, while two others failed to improve.
An additional two patients have been treated more recently, and doctors say it is too early to determine the results.
The glioblastoma treatment uses the Sabin 1 virus strain developed in the 1950s to vaccinate humans against polio disease, which causes paralysis by infecting cells in the spinal cord.
To ensure greater safety, researchers swapped out a piece of genetic information to alter the virus so it could not grow in normal brain cells, said Matthais Gromeier, a polio-virologist at Duke who developed the therapy.
The modified virus has been tested in both primates and humans over the past decade, Gromeier said.
“We have tested it with a sufficient amount of patients to know it is absolutely safe in humans,” he said. “We have not observed any toxic side effects.”
Exactly how the poliovirus works against cancer cells is still being studied, but Gromeier thinks it triggers a response in the patient’s immune system.
“Since we are all vaccinated against polio, we already have immune defenses,” he said. “So when we infect the tumour, our immune system will come in and respond and turn against the patient’s tumour.”
The poliovirus is among a number of viral agents being studied in cancer research, said Jan Buckner, chairman of the Department of Oncology at Mayo Clinic in Rochester, Minnesota, who heard a presentation on the Duke research at a recent meeting of the American Society of Clinical Oncology.
“In concept, this and many other viral therapies are promising,” Buckner said.
Cancer specialists at Mayo Clinic and other research institutions are testing therapies that use a variety of disease-causing viruses, including measles and the vesicular stomatitis virus, which is related to rabies.
Viruses may work against cancer by causing the body’s immune system to defend itself, but there is also evidence that some viruses may directly attack tumour cells. Others are being targeted toward specific cancer gene mutations, Buckner said.
“Which property of virus therapy is going to prove to be most effective remains to be seen,” he said.
Researchers are optimistic about the future of poliovirus as a weapon against brain and other types of cancers. “It seems promising, but we will still need to look at more patients and see if we can reproduce these results,” Desjardins said.
Glioblastoma is the most common and aggressive type of brain cancer and is usually fatal. Standard treatment includes surgery, chemotherapy and radiation, with the tumours reoccurring in 95% of cases – nearly 50% within eight weeks of treatment.
“We typically expect about a year of survival” after traditional treatment, Desjardins said. “And it really affects who they are, how they function. Mostly it affects people in their late 40s to mid 50s.”
Lipscomb’s case is unusual because she was so young when the tumour developed. Her cancer was discovered after she suffered a series of debilitating headaches in spring 2010, near the end of her freshman year at University of South Carolina-Upstate in Spartanburg.
“It got to the point that I couldn’t eat anything,” Lipscomb said. “I couldn’t dress or bathe myself. All I could do was lay in bed.”
A brain scan revealed a tennis-ball-sized tumour in her brain just behind her right eye, which was surgically removed in June 2010.
She underwent months of chemotherapy and radiation – and still was given just five years to live.
“But I’m religious, and I didn’t believe I was going to die from cancer,” she said. “I’ve never felt like I was going to die, no matter what anyone else thought.”
Lipscomb resumed her collegiate life in the spring of 2011, with help from a couple of stylish wigs. But in April 2012, her world was rocked again when she learned the tumour had returned.
Lipscomb immediately agreed when Desjardins offered her the chance to join the poliovirus research effort, even knowing she would be the first patient to enter Phase 1 of the trial, which gauges the safety and dosage for an experimental treatment.
Her mother, Kelli Lusk, initially had a few reservations. “But it was her decision, her body, and we supported her,” Lusk said.
The procedure was carried out in May of last year and came with few adverse side effects.
Monday’s MRI checkup brought more good news to Lipscomb, who has been making the nine-hour round trip to Duke every few weeks for evaluation.
Her tumour has so far contracted from the size of a lime to no larger than a green pea.
“That’s awesome,” Lusk said.
Lipscomb is heading back to school this fall, where she has just been accepted into the nursing programme. She’s planning to work in oncology after graduation. – The News & Observer/McClatchy-Tribune Information Services