By MARILYNN MARCHIONE AP Medical Writer
SAN ANTONIO — New drug combinations are helping women with early breast cancer. Using two drugs that more precisely target tumors doubled the number of women whose cancer disappeared compared to those who had only one of the drugs, doctors reported Friday.
It was the first test of Herceptin and Tykerb together for early-stage disease. They aim at a protein called HER-2 that is overproduced in about one-fourth of all breast cancers. Herceptin blocks the protein on the cell's surface; Tykerb does it inside the cell.
Dr. Jose Baselga, associate director of the Massachusetts General Hospital Cancer Center, led a study when he previously worked in Barcelona, Spain, that tested these drugs alone and in combination in 455 patients who also were given the chemotherapy drug paclitaxel.
The patients were treated for about four months before surgery to remove their tumors and for nine months afterward. Doctors have been testing drugs in advance of surgery to shrink tumors and make the operation less drastic, and to get an idea quickly if these drugs will help a patient.
Just over half of the women who received Herceptin and Tykerb were discovered to have no signs of invasive cancer when their surgeries were done, versus only 25 to 30 percent of those given just one of these drugs.
Tykerb had more side effects, mostly diarrhea. But the main side effect of combo treatment is to the wallet: Tykerb pills cost $5,000 to $6,000 per month. Herceptin costs more than $4,000 a month plus whatever doctors charge to infuse it.
"The possibility that we have here is to enhance the number of patients that are cured" and avoid more treatment down the line that might cost more, Baselga said.
However, Dr. Neil Spector of the Duke Cancer Institute said cost "is a real consideration."
Yet he called the results "really exciting" and said the future of cancer care is approaches like this that use targeted drugs well matched to patients' tumor profiles.
British-based GlaxoSmithKline PLC makes Tykerb; California-based Genentech, now part of the Swiss company Roche, makes Herceptin.
A second study in Germany pitted the two drugs against each other in 600 women with early breast cancer also getting standard chemotherapy for six months before surgery. Herceptin won: 31 percent saw their tumors disappear versus 22 percent on Tykerb.
The studies were reported Friday at the San Antonio Breast Cancer Symposium.