- 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.