SATURDAY, May 31 (HealthDay News) -- Adding the drug Avastin to
chemotherapy lengthened progression-free survival in women with
advanced breast cancer, new research shows.
Previous studies have found that adding Avastin (bevacizumab) to
the chemotherapy drug Taxol (paclitaxel) in women with advanced
breast cancer actually doubled progression-free survival.
Avastin is already approved for use in metastatic colon cancer,
non-small cell lung cancer and, recently, in newly diagnosed
metastatic breast cancer (in combination with paclitaxel).
"Avastin is an anti-angiogenesis drug [one that inhibits blood
supply to the tumor] that appears to have activity across a variety
of cancers," Dr. Nancy Davidson, director of the breast cancer
program at Johns Hopkins Kimmel Cancer Center in Baltimore and
president of the American Society of Clinical Oncology (ASCO), said
during a teleconference earlier this month.
"Angiogenesis is clearly a very important process in the
tumorogenesis of many malignances, and one of the first agents
we've had available to us in the clinic is Avastin, which has
demonstrated some efficacy in several genotypes," said study author
Dr. David Miles, a medical oncologist at the Mount Vernon Cancer
Centre in Middlesex, U.K.
Miles, who is presenting the findings this weekend at the
American Society for Clinical Oncology annual meeting in Chicago,
spoke at a Saturday news conference.
The current study looked at Avastin added to the chemotherapy
agent Taxotere (docetaxel). Taxotere is more commonly used outside
the United States, while Taxol is more commonly used in the United
States.
This phase III trial involved 736 patients randomized into one
of three groups: Taxotere alone, Taxotere plus a high dose (15
mg/kg) of Avastin, or Taxotere plus a low dose of Avastin (7.5
mg/kg). The lower dose of Avastin is the current standard dose for
breast cancer treatment, while the higher dose is the standard dose
for colon cancer.
After a median follow-up of almost one year, women taking the
lower dose of Avastin were 21 percent less likely and those taking
the higher dose 28 percent less likely to have a recurrence
compared to those receiving chemo alone. More than half (55.2
percent) in the low-dose group and two-thirds (63.3 percent) in the
high-dose group saw their tumors shrink, compared to 44.4 percent
in the placebo group.
Patients receiving Avastin did have more severe side effects (74
percent to 75 percent versus 67 percent in the chemotherapy-alone
group).
Final data on overall survival is not yet available. According
to Dr. Eric Weiner, director of the breast oncology center at
Dana-Farber Cancer Institute in Boston and moderator of the
Saturday news conference, "it is unlikely there will be a survival
benefit."
The U.S. Food and Drug Administration tends to approve second
and third-line drugs based on progression-free survival and drugs
for the first-line setting on survival, Weiner said, adding that he
"personally does not understand that approach."
Progression-free survival can be seen as a quality-of-life
improvement. "Having the disease under control for longer, as long
as the toxicity of treatment is not substantial, is something that
is well worth it," Weiner said. "So a drug that can substantially
improve profession-free survival is a drug that can at least, in
some patients, make their lives that much better while they are
dealing with this illness."
More information
The
American Society of Clinical Oncology has more
information on breast cancer.
