The aggressive brain cancer that killed John McCain in August 2018 could someday be treated with a vaccine, according to new research.
An experimental vaccine for glioblastoma had promising results in an early-stage clinical trial, according to research presented recently at the American Association for Cancer Research’s annual meeting.
While many vaccines are used to prevent a disease from ever developing, this one, developed by Jefferson Health and Imvax, is used in patients who have already been diagnosed with glioblastoma to help treat the existing cancer. In the study, thirty-three newly diagnosed patients received the vaccine, called IGV-001. Compared with a group of 35 patients treated with the standard of care for glioblastoma, those who got the vaccine saw less cancer progression and survived one and a half times longer.
The median prognosis of glioblastoma is only 14.6 months with standard treatment; with the highest dose of the vaccine, that prognosis increased to 21.9 months, according to the research. And the vaccine caused no adverse effects, either.
The vaccine is made up of cancer cells taken from the patient’s own tumor, collected during surgery to remove some or all of the tumor, depending on the specific tumor and its location in the brain. The cancer cells collected are then treated with a synthetic nucleic acid called an antisense ologodeoxynucleotide (AS-ODN), which attacks a specific receptor known to spur the spread and growth of tumors. When used as a vaccine in the patient, the research shows that the immune system activates against brain tumor cells, said immunologist D. Craig Hooper, Ph.D., of Sidney Kimmel Cancer Center – Jefferson Health in a press release.
Unfortunately, it will be some time before the vaccine might hit the market, as there are plans for further clinical trials. This recent trial was a phase 1b trial, which looks primarily at dosage, side effects, and body responses to the treatment, according to the American Society of Clinical Oncology.
"The response we see in some patients is very encouraging," said David Andrews, M.D., professor of neurosurgery at the Vickie & Jack Farber Institute for Neuroscience — Jefferson Health and co-founder of Imvax. "We look forward to initiating a phase II trial later this year to confirm these phase 1b results.” Phase II trials look further into the safety and efficacy of a treatment and last about two years. To be approved by the Food and Drug Administration, drugs typically go through three stages of clinical trials.
Rates for new cases of brain and other nervous system cancers, including glioblastoma, have been declining slightly — an average of 0.2 percent — each year over the last 10 years, according to the National Cancer Institute. However, death rates have been increasing an average of 0.4 percent yearly from 2006-2015.