Vaccine May Treat Lung Cancer
Experimental Vaccine Shows Promise in Some Early-Stage Lung Cancer
By
Salynn Boyles
WebMD Health News
Reviewed By
Louise Chang, MD
April 25, 2008 — An experimental vaccine that works by training the immune
system to kill specific tumor cells is showing promise for the treatment of
early lung cancer, researchers report.
The immune-system-boosting vaccine targets a protein expressed in certain cancer cells, but not in normal
cells, known as MAGE-A3.
About 35% of non-small-cell lung cancers (NSCLC) have this protein, which is
also present in some melanomas and head and neck cancers.
In a trial of early-stage lung cancer patients whose tumors expressed
MAGE-A3, treatment with the vaccine was shown to reduce the risk of relapse
after surgery.
Long-term follow-up results from the early trial of the immunotherapy were
presented at the 1st European Lung Cancer conference in Geneva,
Switzerland.
"The principle behind this approach has potential for many different
types of cancer," researcher Johan Vansteenkiste, MD, PhD, tells WebMD.
"The principle is that you teach the patient's immune system to eliminate
cancer cells that express certain proteins."
MAGE-A3 Vaccine
The vaccine therapy has not been compared head-to-head with chemotherapy,
which is often given to surgically treated lung cancer patients to reduce their
risk of relapse.
But Vansteenkiste says the immunotherapy-treated patients in the phase II
study had outcomes similar to those seen among chemotherapy-treated patients,
with almost no side effects.
"Many surgically treated lung cancer patients are not able to tolerate
the side effects of chemotherapy, either because of their age or because of
other health issues," he says. "This approach is a promising
alternative."
A total of 182 patients with NSCLC were included in the early study,
sponsored by drugmaker GlaxoSmithKline, which is developing the vaccine
therapy. All the patients had cancers that expressed MAGE-A3.
After having surgery to remove their tumors, 122 patients were randomly
assigned to treatment with the MAGE-A3-targeting vaccine and 60 patients got
placebo vaccines.
The patients were given five injections every three weeks at the beginning
of treatment and then eight injections every three months later on for a total
of 27 months, Vansteenkiste says.
After 44 months of follow-up, 69 of the 182 patients had cancer recurrences,
including 57 deaths. The researchers report that the treatment was
well-tolerated. The MAGE-A3-treated patients seemed less likely to have
recurrences and die from their disease than the placebo-treated patients,
although this is being further evaluated in an ongoing phase III study for
efficacy.
Immunotherapy vs. Chemotherapy
This year in the U.S., 215,000 new cases of lung cancer will be diagnosed
and close to 162,000 people will die from the disease, according to National
Cancer Institute projections.
Surgery is the standard treatment for patients with early-stage disease, but
about 50% of patients who have surgery end up dying of their lung cancer,
Vansteenkiste says.
He says adding chemotherapy to surgery boosts the survival rate by about
10%, a rate similar to that seen in the MAGE-A3 trial.
Last year, GlaxoSmithKline began recruitment for a phase III study of the
cancer vaccine, which will include more than 2,000 patients whose cancers
express MAGE-A3.
The placebo-controlled trial will include patients treated with the vaccine
both instead of and in addition to chemotherapy.
"We want to see if there is an extra benefit to adding the immunotherapy
to chemotherapy," he says.
Len Lichtenfeld, MD, of the American Cancer Center, tells WebMD that it
remains to be seen if the MAGE-A3 vaccine will prove to be a useful treatment
for lung cancer.
"The study suggests that there may be some benefit here, but clearly a
larger trial will tell us more," he tells WebMD.
He adds that it will not be clear if the immunotherapy works as well as
chemotherapy until the two treatments are compared head-to-head.
SOURCES: 1st European Lung Cancer Conference, Geneva, Switzerland, April 25,
2008. Johan Vansteenkiste, MD, PhD, department of pulmonology, University Hospital
Gasthulsberg, Leuven, Belgium. Len Lichtenfeld, MD, MACP, deputy chief medical officer, American Cancer
Society. National Cancer Institute web site.
© 2008 WebMD Inc. All rights reserved.
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