Vaccination News Home Page subscribe Vaccination NewsLetter
http://www.businessweek.com/1999/99_15/b3624151.htm
A Shot in the Arm for
Cancer Patients?
When Ernest Graf,
retired president of Ben Kahn Furs in New York, was diagnosed with prostate
cancer in 1993, he underwent radiation treatment. Then he opted to receive an
experimental vaccine developed by Memorial Sloane-Kettering Cancer Center in New
York. ''I didn't want the side effects'' associated with hormonal therapy, such
as lethargy and diminished libido, says Graf, 79, who received four shots over
18 months. With his cancer now in remission, he credits his good health to the
vaccine and to an active lifestyle that includes biking and skiing: ''It
strengthened my immune system without slowing me down,'' he says.
Graf is one of thousands of patients in the past decade who have received
experimental vaccinations that prompt their immune systems to fight cancer. The
vaccines are easy to administer and have few side effects beyond occasional
flu-like symptoms and irritation at the site of the shots. While by no means a
cure, they hold promise as a supplement to such standard anticancer weapons of
surgery, radiation, and chemotherapy.
Already in use in Europe, the first cancer vaccines have yet to become widely
available in this country. That may change next year, pending U.S. Food & Drug
Administration approval of colon-cancer vaccine OncoVAX from Rockville
(Md.)-based Intracel and melanoma vaccine Melacine from RibiImmunoChem Research
of Hamilton, Mont. Clinical trials of at least two dozen others for ovarian,
breast, lung, pancreatic, and prostate cancer are under way.
Scientists have been on the trail of a cancer vaccine since the 1800s, when they
noticed that tumors sometimes shrank when patients contracted bacterial
infections. Indeed, the first vaccines used bacteria that revved up the immune
system. But they didn't work well because cancer is hard for the body to I.D. as
an enemy. Basically, the bacterial vaccines signaled the immune system to fire
without giving it a target. Only in the last decade have researchers set their
sights more accurately.
Unlike vaccines for measles and polio, this bunch of experimental vaccines are
intended to prevent the recurrence of cancer in patients who have had the
standard treatments. Depending on the type of cancer and the patient's response,
treatment may involve injections given over six weeks to two years. You can get
a list of institutions conducting clinical trials on the vaccines from the
National Cancer Institute (800 4-CANCER; cancernet.nci.nih.gov/pdq.htm).
Since the 1970s, researchers have latched on to three approaches to making the
vaccines (table). Autologous vaccines use a person's own tumor cells, which are
irradiated and combined with a bacterium or other agent that elicits an immune
response. The body's violent reaction to the concoction, the thinking goes,
creates a killer instinct toward new tumors. A study in British medical journal
The Lancet in January said Intracel's autologous vaccine cut the colon-cancer
recurrence rate by 50% over five years in patients in whom the disease had begun
to spread beyond the tumor site. Since the vaccine has to be tailored to each
person, Intracel plans to set up facilities around the country to ease delivery.
Several teams, meanwhile, are working on more generalized vaccines. Dr. Philip
Livingston and colleagues at Sloane-Kettering have identified a molecule, GM2,
that shows up on most melanoma cells. They make it in the lab and combine it
with substances derived from mollusks and the bark of the South American soap
bark tree. The brew, Livingston says, elicits ''an immune response in virtually
100% of patients.'' A study with 600 subjects has been under way for 2 1/2 years
to see if this response reduces recurrence.
The third approach is to use genetic material. Vaccines for pancreatic and
prostate cancer developed in 1992 at Johns Hopkins University Medical School in
Baltimore, and now in clinical trials, combine a gene for a ''messenger
protein,'' cytokine, with a patient's tumor cells. It's like pinning a note to
the tumor cell that reads: ''Kill me and anything that looks like me,'' says Dr.
Drew Pardoll, professor of oncology at Hopkins. Not a bad ploy to add to the
anticancer battle plan.
By Kate Murphy
ALL INFORMATION, DATA, AND
MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION
PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS
OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR
LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND
COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH
YOUR HEALTH CARE PROVIDER.