Transtuzumab Boosts Metastatic Breast Cancer Survival Rates

Transtuzumab

A new drug that aimed at metastatic breast cancer has passed phase 3 clinical trials. Results were presented at the American Society of Clinical Oncology conference in Chicago. The clinical trial compared trastuzumab emtansine (T-DM1) with standard therapy for HER2-positive breast cancer and according to the study, treatment with T-DM1  had positive results and a higher rate of survival.

The study included 1,000 patients with Her2 positive metastatic breast cancer,  human epidermal growth factor receptor 2. HER2 is a receptor present on the cell surface, encoded by the Her2  gene. This receptor is responsible for regulating division, growth and repair of breast cells. In some breast cancers, there is a Her2 gene amplification but the  Her2 gene is not working properly. Thus there is a overexpression of HER2, which cause the anarchic proliferation of breast cells. It should be noted that HER2 gene mutation can be found not only in breast cancer but other cancers also. HER2-positive cancers grow faster and have a greater tendency to spread thus metastasis occurs more frequently than in other types of cancer. Therefore, researchers have developed therapies that specifically target this receptor, such as Transtuzumab.

Trastuzumab

Transtuzumab is a monoclonal antibody that binds to HER2 receptor and prevent cancer cells to multiply. Also, this drug inhibits angiogenesis (tumor vessel growth).Transtuzumab can be used alone or in combination with other therapies only if the tumor expresses Her2 receptors, otherwise Transtuzumab has no effect. Unfortunately, some patients do not respond to this therapy as resistance develops. Lapatinib can be also used to treat metastatic breast cancer alone or in combination with another drug.

According to trial the new drug, trastuzumab emtansine (T-DM1), may increase survival in patients with metastatic breast cancer. The average survival was 9.6 months in those receiving T-DM1 compared with 6.4 months in those treated with standard therapy. Average survival at 2 years was 65% for those treated with T-DM1 and 47.5% for those treated with standard therapy. Lead study author Kimberly Blackwell, professor of medicine at Duke University, noted that the finding is striking: “The drug worked. It was significantly better than a very effective approved therapy for HER2 overexpressing metastatic breast cancer”. He also added that the new drug has a much lower toxicity. Until now there have been cases of loss of hair in patients receiving T-DM1.

Although the drug has to pass other clinical trials to certify it really enhances survival rates, T-DM1 is certainly a huge step forward  in approaching metastatic forms of breast cancer.