Mayo Clinic Researchers Say Triple Drug Combination is Promising Option to Treat...

Mayo Clinic Researchers Say Triple Drug Combination is Promising Option to
Treat Metastatic HER2+ Breast Cancer

ORLANDO, Fla., May 18 /PRNewswire-USNewswire/ -- Combining two chemotherapy
drugs with trastuzumab (Herceptin) to treat women who have metastatic HER2+
breast cancer may offer physicians another choice in their treatment options.

At the 45th Annual Meeting of the American Society of Clinical Oncology
(ASCO), researchers from the Mayo Clinic campus in Florida report that using a
combination of capecitabine, vinorelbine, and trastuzumab offers a treatment
option that is at least as beneficial as other current options - and doesn't
cause hair loss in patients.

"This is a very well tolerated regimen. The combination is a good example of
an excellent therapeutic ratio: good activity and low toxicity," says the
study's senior investigator, Edith Perez, M.D., director of Mayo Clinic's
Breast Center in Jacksonville.

The clinical trial is the first in the United States to study this particular
combination of therapies in patients with HER2+ metastatic breast cancer,
researchers say. The chemotherapy regimen was previously tested in Europe and
demonstrated good anti-tumor activity and low toxicity, so Mayo researchers
combined it with Herceptin, says the study's lead author, Winston Tan, M.D., a
medical oncologist at Mayo Clinic.

Sixty-seven percent of the 45 patients in this trial responded to treatment,
with their tumors decreasing in size by at least 30 percent. Historic response
to conventional drug regimens (one chemotherapy drug with Herceptin) that are
currently used to treat metastatic HER2+ breast cancer is about 50 percent,
Dr. Tan noted.

"The results are encouraging, and would support a larger, randomized Phase III
study," he says. "This is a Phase II study of this triple combination, so we
would need to study this treatment against the standard best two-drug
treatment in a randomized Phase III study to know if this triplet is more
effective."

"This regimen seems to be a very reasonable choice, and it offers the added
advantage that women who use it do not lose their hair," he says. The drug
combination used most commonly for patients with HER2+ breast cancer that has
spread -- paclitaxel or docetaxel with trastuzumab -- always causes hair loss,
Dr. Tan says.

All of the agents are approved for use by the U.S. Food and Drug
Administration for cancer, although vinorelbine has not been approved for this
particular treatment regimen in the U.S., the researchers say.

Capecitabine chemotherapy is not usually paired with trastuzumab because some
studies had suggested it does not offer a synergistic, or additive, benefit.
However, Dr. Tan says that newer research has shown the combination is in fact
promising.

Among the patients studied, 28 (58 percent) had a partial response, a
reduction in the size of the metastatic tumor of more than 30 percent by
computed tomography. Four patients had a complete response with no more
evidence of metastasized tumors on diagnostic scans, the researchers say.
Average survival was improved when compared historically to traditional
treatment, Dr. Tan says. "Normally, survival for metastatic breast cancer is
two years," he says. "In this study, average survival was 27 months." He
cautioned that these results should be validated in a Phase III study.

"The toxicity was tolerable, no more than is seen with a two-drug regimen," he
says. The majority of patients (61 percent) experienced a low white blood
count, but only about ten percent of patients had fatigue or other common side
effects.

Tan stressed that this regimen does not offer curative treatment, but it
offers patients an improved quality of life compared to other commonly used
regimens.

"It is very difficult to treat cancer that has spread, but we believe that
combining treatments together is important to help shrink tumors that are
rapidly growing," he says.

He adds that 80 percent of the patients who showed benefit had been treated
with other chemotherapy drugs -- mostly anthracyclines and paclitaxel -- and
at least half of the patients had used trastuzumab in the adjuvant or
metastatic setting as well. "They still got a response to these combination of
two chemotherapies plus the biological agent, and that is encouraging," he
says.

About Mayo Clinic
Mayo Clinic is the first and largest integrated, not-for-profit group practice
in the world. Doctors from every medical specialty work together to care for
patients, joined by common systems and a philosophy of "the needs of the
patient come first." More than 3,300 physicians, scientists and researchers
and 46,000 allied health staff work at Mayo Clinic, which has sites in
Rochester, Minn., Jacksonville, Fla., and Scottsdale/Phoenix, Ariz.
Collectively, the three locations treat more than half a million people each
year. To obtain the latest news releases from Mayo Clinic, go to
www.mayoclinic.org/news. For information about research and education, visit
www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource
for your health stories.

SOURCE Mayo Clinic

Paul Scotti of Mayo Clinic, +1-904-953-2299 (days), +1-904-953-2000
(evenings), scotti.paul@mayo.edu