Two New Drug Combos May Fight Advanced Breast
WEDNESDAY, Dec. 7 (HealthDay News) -- Breast cancer researchers
report they are heartened by the results of two new studies that
show combination therapies might improve survival for women with
two different types of advanced tumors.
One of the drugs, everolimus (Afinitor), boosted
progression-free survival in women with hormone receptor-positive
breast cancer but is not yet approved by the U.S. Food and Drug
Administration for this indication. The other drug, pertuzumab,
improved survival with HER-2 positive tumors, but has not received
any FDA approval.
So, the immediate clinical implications are probably "none,"
said Dr. Jose Baselga, lead author of both studies, which are to be
presented at the 2011 San Antonio Breast Cancer Symposium Wednesday
and published simultaneously in the
New England Journal of Medicine.
In time, though, they could be "practice-changing," said
Baselga, chief of hematology/oncology at Massachusetts General
Hospital Cancer Center in Boston. "The benefits were very
In the first study, 724 postmenopausal women with hormone
receptor-positive breast cancer were randomly assigned to receive
the aromatase inhibitor Aromasin (exemestane) plus a placebo or
Aromasin plus Afinitor, which is already approved for treatment of
Women receiving Afinitor lived an average of 7.4 months without
a recurrence, versus only 3.2 months in the placebo group.
Half of the women receiving Afinitor showed some kind of tumor
response compared to 25 percent in the control group.
"This is one of the most positive studies in hormone receptor-positive breast cancer," said Baselga.
It's not clear yet whether the drug improves overall survival,
said the authors of the study, which was funded by Afinitor's
The second study involved 808 patients with HER2-positive breast
cancer which had already spread to other parts of the body.
HER2-positive breast cancer, which accounts for roughly 20
percent of all breast cancers, is commonly treated with Herceptin
(trastuzumab) and chemotherapy. Here, participants were randomly
given Herceptin, chemotherapy and a placebo or Herceptin,
chemotherapy and pertuzumab.
Women receiving pertuzumab went an average of 18.5 months before
experiencing a recurrence compared to 12.4 months in the control
group, a 38 percent reduction in risk.
"A six-month improvement is very good," Baselga said.
Herceptin and pertuzumab both block the HER2 growth factor,
which causes these types of tumors to proliferate, although the
drugs bind to different parts of the HER2 protein. But, pertuzumab
goes a step further and suppresses HER2 from binding to HER3 growth
This study was funded by F. Hoffman-La Roche and Genentech,
which make pertuzumab.
Dr. Jay Brooks, chairman of hematology/oncology at Ochsner
Health System in Baton Rouge, La., said the results were
"intriguing" and "could potentially be very helpful in patients
with two specific subsets of breast cancer."
But he also pointed out that both drugs are very expensive
(possibly up to several thousand dollars a month) and are not yet
approved for these specific uses.
"As these studies mature, this will be looked at by physicians around country to try to help patients," he said.
The U.S. National Cancer Institute has more on
targeted therapies for breast cancer.
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