New Drug Holds Promise in Triple Negative Breast Cancer Fight

One of the most aggressive forms of breast cancer, women diagnosed with triple negative breast cancer lack the three "receptors" known to fuel most tumors: estrogen receptors, progesterone receptors and human epidermal growth factor receptor 2 (HER2). Triple negative breast cancer is more likely to recur than other breast cancer subtypes, and does not respond to receptor-targeted treatments. This means patients must rely almost exclusively on chemotherapy and its harmful side effects for treatment.

However, laboratory studies and early trials of a new drug - known alternately as BSI-201 or iniparib – show its marked effectiveness in reducing tumors when used alongside other chemotherapy drugs.

According to researchers, women who have triple negative breast cancer have defects in BRCA1 and BRCA2, two genes with a major role in repairing cell DNA. Scientists discovered that cells with these defects are especially sensitive to cancer treatments called poly-ADP-ribose polymerase (PARP) inhibitors. BSI-201, or iniparib, is such a drug and has been shown to cause the death of cancer cells that have these defective genes.

In Phase II drug trials, 62 percent of patients given the drug along with chemotherapy treatments had clinical benefits compared with 21 percent who received chemotherapy alone. The combined treatment also increased overall survival from 5.7 months to 9.2 months when compared to the chemotherapy-only patients.

While significant research still is needed, positive results could eventually transform iniparib into an exciting new treatment for women fighting difficult-to-treat triple negative breast cancer.

More information about triple negative breast cancer is available at www.tnbcfoundation.org. For more information about the iniparib (BSI-201) studies, you may visit www.physorg.com or the Sanofi-Aventis Oncology website at www.sanofiaventisoncology.com.

November 19, 2010