According to results presented at the 22nd annual Miami Breast Cancer Conference, the chemotherapy agent Abraxane™ improves survival over paclitaxel (Taxol®) in the treatment of recurrent breast cancer.
Breast cancer is one of the most common cancers diagnosed in women. It is estimated that approximately 250,000 women are diagnosed annually in the United States and 40,000 deaths are attributed to breast cancer each year. Although treatment for patients with early-stage breast cancer, or cancer that has not spread from its site of origin, results in high cure rates, some patients ultimately experience a recurrence and spread of their cancer. Metastatic breast cancer refers to cancer that has spread from the breast to distant sites in the body, often invading vital organs. Survival for patients with metastatic breast cancer is poor, with the average survival time from diagnosis of this advanced stage of cancer being 18 to 30 months.
Treatment for metastatic breast cancer is aimed at improving the duration of survival and/or quality of life for patients, but often not with the intent to cure. Paclitaxel is a chemotherapy agent that is commonly used in the treatment of breast cancer. Patients with cancer that has recurred following previous therapy and has developed into metastatic breast cancer are often treated with paclitaxel. The formulation of paclitaxel includes agents that allow for the proper storage and administration of the drug; however, these agents are also responsible for the development of many side effects associated with paclitaxel.
Abraxane™ is a new form of paclitaxel that is bound with albumin, which is a type of protein normally found in the human body. This form of paclitaxel delivers high concentrations of the active ingredient into the cancer cells and reduces the incidence of side effects, compared to the original form of the drug. Abraxane™ was recently approved by the U.S. Food and Drug Administration (FDA) for the treatment of patients with breast cancer who have stopped responding to prior therapies that included a class of commonly used chemotherapy agents referred to as anthracyclines (doxorubicin, epirubicin, Doxil®). Clinical trials evaluating the effectiveness of Abraxane™ in different stages of breast cancer are ongoing.
Results from previous trials evaluating Abraxane™ have included data regarding overall anti-cancer responses and time to cancer progression. The recently reported results include survival data in the evaluation of Abraxane™ in the treatment of advanced breast cancer. The trial included 460 patients with metastatic breast cancer. Some patients had not received prior therapy and some patients had received one or more prior therapeutic regimens and experienced a progression of their cancer. In the trial, patients were treated with either Abraxane™ or paclitaxel and were directly compared. Overall, anti-cancer responses were nearly doubled and the duration of survival was increased by 10 weeks in the group of patients treated with Abraxane™ compared to those treated with paclitaxel (65 weeks versus 55 weeks, respectively). The group of patients who had received prior therapy experienced the greatest improvement with the treatment of Abraxane™ compared to paclitaxel, with average survival times of approximately 56 weeks for those treated with Abraxane™, compared to 46 weeks for those treated with paclitaxel.
The researchers have concluded that treatment with Abraxane™ improves survival compared to paclitaxel in the treatment of recurrent, metastatic breast cancer. Patients with advanced breast cancer may wish to speak with their physician about their individual risks of treatment with Abraxane™.
Reference: New Antitubulin Agents. Proceedings from the 22nd annual Miami Breast Cancer Conference. Presented by Dr. Perez. Friday February 25, 2005. 2:45 pm. Miami, Florida.