Drug Combo Wipes Out Tumor Cells
Herceptin-Tykerb Combo Helps Before Surgery for Early Breast Cancer
More Side Effects With Tykerb
Tykerb, both alone and in combination with Herceptin, was associated with a higher rate of serious diarrhea: It affected 23% of women on Tykerb, 21% of women on the combo, and 2% of women on Herceptin alone.
There were also more serious liver function problems with Tykerb: About 13% and 9% of women in the Tykerb alone and combo groups were affected, respectively, vs. 1% in the Herceptin group.
Women taking Tykerb were also more likely to have a low white blood cell count and skin rashes. One woman taking the combination treatment died, but the cause is not yet known, according to Baselga.
The study was funded by GlaxoSmithKline, which makes Tykerb.
The findings were presented at the San Antonio Breast Cancer Symposium.
Herceptin vs. Tykerb Before Breast Cancer Surgery
Also at the meeting, German researchers reported that when given with chemotherapy, Herceptin alone beat out Tykerb alone at eradicating cancer cells in the breast and lymph nodes prior to surgery.
The study involved about 600 women with early and locally advanced cancer. Tumor cells were wiped out in 31% of women given Herceptin and 22% of those given Tykerb.
A total of 7% of women on Tykerb dropped out due to side effects vs. 3% on Herceptin.
The findings were presented by Michael Untch, MD, head of the multidisciplinary breast cancer department at Helios Clinic in Berlin.
Currently, doctors don't know if tumor cells have been eradicated until the tumor is surgically removed and examined by a pathologist.
But the researchers plan to examine more than 1,500 tumor samples to find out if certain genetic signatures can predict -- with near 100% accuracy -- which women will be cured by the HER2-targeted drugs alone and won't even need surgery, Untch tells WebMD.
The study was funded By Sanofi, Roche, and GlaxoSmithKline.
Pertuzumab Also Shows Promise Before Breast Cancer Surgery
A third, earlier-stage study presented at the meeting showed that adding the experimental drug pertuzumab to Herceptin and chemotherapy wipes out 46% of tumor cells prior to surgery.
"That's about 50% more than achieved with [the chemotherapy drug Taxotere] and Herceptin, the standard therapy," says Luca Gianni, MD, director of medical oncology at the Fondazione IRCCS Istituto Tumori di Milano in Italy.