According to results presented at the 22nd annual Miami Breast Cancer Conference, treatment with the chemotherapy agent Abraxane™ (paclitaxel protein-bound particular for injectable suspension) reduces the risk of death by 29 percent compared to treatment with paclitaxel (Taxol®) in women with advanced breast cancer.
Breast cancer is among the most common cancers diagnosed in women. It is estimated that approximately 250,000 women are diagnosed annually in the United States; 40,000 deaths are attributed to breast cancer each year. 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 either the duration of survival, quality of life for patients, or both, but rarely 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. Paclitaxel contains agents that allow for the proper storage and administration of the drug; however, these agents are also responsible for many side effects associated with the drug.
Abraxane is a new form of paclitaxel that is bound with albumin-a type of protein normally found in the human body. This form of paclitaxel delivers higher concentrations of the active ingredient into the cancer cells and produces fewer side effects than 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. These former treatments 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 the period before the cancer continues to spread. Recent 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, while others 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 in the group of patients treated with Abraxane compared to those treated with paclitaxel. The group of patients who had received prior therapy experienced the greatest improvement with the treatment of Abraxane compared to paclitaxel-for those treated with Abraxane, average survival time was approximately 56 weeks, whereas those treated with paclitaxel survived an average of 46 weeks.
The researchers have concluded that treatment with Abraxane improves survival more effectively than paclitaxel in the treatment of metastatic breast cancer. Furthermore, treatment with Abraxane is associated with fewer side effects than paclitaxel. Patients with advanced breast cancer may wish to speak with their physician about their individual risks of treatment with Abraxane.
Reference: American Pharmaceutical Partners. American Pharmaceutical Partners Announces Presentation of ABRAXANE Survival Data at 22nd Annual Miami Breast Cancer Conference. Available at: http://www.appdrugs.com/022505PR.html . Accessed June 2005.