The results of a recent study presented at the 29th annual meeting of the European Society of Medical Oncology held in Vienna, Austria (October 29 to November 2, 2004) indicate that treatment with Abraxane™ produces a response rate of 15% among patients with metastatic breast cancer.
Breast cancer is the most common cancer diagnosed in women in the United States, claiming the lives of approximately 40,000 women annually. 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 (Taxol®) is a chemotherapy agent that is commonly used in the treatment of breast cancer. Patients whose cancer 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. In a randomized, phase III trial, Abraxane™ administered every three weeks produced favorable response rate and cancer-free survival compared to paclitaxel.
The trial presented at ESMO included 106 patients who received three weekly administrations of Abraxane™ followed by 1 week of rest. This regimen was repeated until disease progression. This treatment schedule produced a 38% probability (chance) of being free from cancer progression at 4 months and surviving 12 months, and a 13% probability of being progression-free at 4 months. The researchers reported that Abraxane™ was well tolerated.
 Blum JL, O’Shaunessy JA, Sandbach J, et al. Weekly Nanoparticle Albumin Paclitaxel (ABI-007) Results in Long-Term Disease Control in Patients with Taxane-Refractory Metastatic Breast Cancer. Proceedings from the 29th ESMO Congress, Vienna Austria, October 29- November 2, 2004, (Abstract #112).
 O’Shaughnessy J, Tjulandin S, Davidson N, et al. ABI-007 (ABRAXANE), a Nanoparticle Albumin-bound Paclitaxel Demonstrates Superior Efficacy vs Taxol in MBC: A Phase III Trial. Proceedings from the San Antonion Breast Cancer Symposium, December 2003, San Antonio TX, (Abstract #44).