New vaccines offer hope against deadly cancers
A 54-year-old cancer patient in Long Island, N.Y., is a pioneer in what many doctors think will become standard treatment in the not-too-distant future: a vaccine against the recurrence of cancer.
The woman — whose name is withheld because of possible recriminations in the job market if future employers were to discover her diagnosis — is crossing her fingers that the vaccine she received a few months age works against the rebound of the deadliest form of brain cancer: glioblastoma.
For more than 20 years, medical scientists have been chasing the possibility of preventing the comeback of a variety of cancers by developing a vast number of experimental vaccines.
Vaccine clinical trials are under way for pancreatic cancer, malignant melanoma and breast cancer, to name a few. Some vaccines have proved promising; others have forced scientists back to the lab. In 2010, the drug Provenge, designed to fend off advanced prostate cancer, became the first anti-tumor vaccine to be approved by the U.S. Food and Drug Administration.
Developing effective treatments against the worst form of brain cancer is important, doctors say, because the survival rate now is dismal, at best. Only 26 percent of patients are alive two years after diagnosis.
Equally troubling, the cancer — though rare — is part of a larger puzzle: An increasing number of brain tumors of all kinds are occurring nationwide.
Dr. Jai Grewal, co-director of the Long Island Brain Tumor Center, said the patient knew she faced difficult odds when her diagnosis came back — grade-four glioblastoma multiforme, the worst possible stage.
Median survival with this form of brain cancer is 12 to 14 months, he said.
“We decided to offer this clinical trial because preliminary data from earlier studies showed the vaccine improved survival,” said Grewal.
A series of small, earlier studies conducted by the vaccine’s maker — Northwest Biotherapeutics in Bethesda, Md. — revealed nearly hard-to-believe results.
Median survival was three years, Grewal said, with 33 percent of patients still alive after four. Further data, contained within the company’s 2010 report, showed 27 percent of treated patients living six years or more. The longest surviving patient lived 10 years after vaccination.
Known as DCVax-Brain, the vaccine is called “personalized” because it involves removing cells from the brain tumor as well as isolating a sample of the patient’s own dendritic cells, master constituents of the immune system. Both are sent to Northwest Biotherapeutics.
Tumor tissue and the patient’s dendritic cells are united in the lab, where biomarkers on malignant cells are used to activate the immune cells to attack the cancer. The primed dendritic cells are injected back into the patient as a vaccine.
Periodic boosters are required to retain immunity.
Patients also receive standard chemotherapy and radiation for more assurance against the cancer’s return.
Grewal’s patient was given her shot more than six months ago.
“I feel great,” she said recently. She said she has returned to work and resumed her usual routines.
Inexplicably, the incidence of all types of brain tumors, including nonmalignant ones, is rising nationwide, according to the National Brain Tumor Society in Boston, a nonprofit advocacy organization.
More than 688,000 people in the United States are living with primary tumors of the brain — cancers that originate there, not ones that traveled to the brain through other forms of cancer. Most of the tumors — 550,000 — are nonmalignant. But the incidence is up from an estimated 612,000 people living with malignant and nonmalignant tumors in 2004.