Three Drug Combination Shrinks HER-2 Positive Breast Cancer Tumors
Researchers at the 33rd Annual CTRC-AACR San Antonio Breast Cancer Symposium have presented data to show that a combination of three drugs – pertuzumab, trastuzumab (Herceptin), and docetaxel – eradicated a significant number of HER-2 positive breast cancer tumors in a Phase II study.
Drug Combination Eradicated Tumors in 46% of Patients
HER-2 positive breast cancer is an aggressive cancer in which a protein called the human epidermal growth factor receptor 2 (HER-2) promotes the excessive growth of cancer cells. It affects about 20 to 30% of breast cancer patients and is associated with poor prognosis.
Trastuzumab (Herceptin) is already approved for the treatment of HER-2 positive cancers and is often used with chemotherapy drugs such as docetaxel. Pertuzumab is still experimental and is the first in a class of drugs known as HER dimerization inhibitors. Both drugs are made by Roche Holding AG.
In the study, 417 women were given four cycles of therapy before they underwent either surgery or as neoadjuvant therapy. Lead investigator Dr. Luca Gianni, director of medical oncology at the National Cancer Institute in Milan, reports that the combination of the three drugs resulted in tumor eradication in 46% of the patients, which is 50% more than was seen with the standard therapy of just Herceptin plus chemotherapy.
The combination of pertuzumab and Herceptin without chemotherapy also had a positive effect, eliminating the tumors in 17% of cases.
Researchers said the combination therapy was not associated with a significant increase in side effects or cardiac risk.
The investigators are working on a follow-up study to see how well the three-drug combination works for women who have already undergone surgery to have their breast cancer tumors removed. Results from an additional trial using the combination as a first-line treatment are expected by the end of next year.
Source Reference: American Association for Cancer Research (2010, December 10). Pertuzumab and trastuzumab combination improved efficacy for women with HER2-positive breast cancer.