Drug Combo Extends Life With Breast Cancer
Women Live Longer With Tykerb-Herceptin Combination After Herceptin Alone Fails
Dec. 11, 2009 (San Antonio) -- For the first time, a drug treatment has been
shown to extend the lives of women with metastatic breast cancer after
Herceptin alone failed.
The treatment involved a one-two punch from Tykerb and Herceptin, both
already used in the treatment of breast cancer.
In a study of nearly 300 women, those given the combo lived four-and-a-half
months longer than those given Tykerb alone. All of the women in the study had
metastatic disease that had continued to spread even after treatments that
Fifty-six percent of the women were still alive a year after treatment began
-- results unheard of in patients with advanced disease who fail Herceptin,
Duke University's Kimberly Blackwell, MD, tells WebMD.
The findings were presented at the San Antonio Breast Cancer Symposium.
How Herceptin and Tykerb Work
About 20% of breast cancer patients have HER2-positive cancers -- tumors
that have too much of a type of protein called HER2, which promotes the growth
of cancer cells. Herceptin blocks HER2 from breast cancer cells.
But metastatic breast cancer eventually becomes resistant to Herceptin. So
researchers have searched for new drugs that target HER2.
Tykerb is such a drug. It zeroes in on two related proteins -- HER2 and EGFR
-- that play a critical role in the growth and spread of cancer.
"It's sort of a double whammy, disabling the HER2 protein in two places
instead of one," Blackwell says.
Tykerb-Herceptin Combo Extends Breast Cancer Patients' Lives
Blackwell and colleagues studied 295 women with metastatic breast cancer,
meaning their cancer had spread to other organs.
All had been treated with Herceptin alone or in combination with various
chemotherapy drugs but were still were getting worse.
Half the women then got Tykerb; the other half got the Tykerb-Herceptin
Those who got the combination therapy were 26% less likely to die over the
course of the study. They lived an average of about 14 months vs. 9.5 months
for those who got Tykerb alone.
Adding Tykerb to Herceptin did not worsen the side effects. "As a clinician,
I think it’s amazing there was no increase in side effects with the combination
of drugs," Blackwell says.
Edith Perez, MD, a breast cancer specialist at the Mayo Clinic in
Jacksonville, Fla., tells WebMD that the results of the study have been eagerly
"In the U.S., there's a tendency of doctors to take women off Herceptin once
it fails to help, but this shows significant benefit to continuing with it and
adding a second targeted agent," she says. Perez says the combo is now being
tested in women with early-stage breast cancer, for whom they expect it to work
The study was funded by GlaxoSmithKline, which makes Tykerb. Blackwell
consults for GlaxoSmithKline and for Genentech, maker of Herceptin.