New Drug Shows Promise Against Triple-Negative Breast Cancer

Article date: January 26, 2011

By Rebecca V. Snowden

An experimental drug called iniparib appears to have a lot of promise against triple-negative breast cancer, an aggressive type of breast cancer.

Triple-negative breast cancer is difficult to treat because its tumor cells lack certain receptors that some common breast cancer treatments, such as tamoxifen and trastuzumab (Herceptin), target. This leaves chemotherapy as the only treatment option for more advanced cancers. The news that iniparib may be effective against advanced triple-negative breast cancer gives hope to many women who currently have few options.

Iniparib is a member of a new class of drugs called PARP inhibitors, which work by blocking an enzyme that helps cells repair their DNA. Cancer cells are sometimes able to use this enzyme pathway to repair the damage done by chemotherapy, which may make them resistant to treatment. In certain types of cancer, blocking this enzyme may help chemotherapy kill the cancer cells. The drugs have shown some promise against hereditary cancers caused by BRCA1 and BRCA2 mutations.

In a recent study published in the New England Journal of Medicine, researchers found that women with metastatic triple-negative breast cancer who received iniparib plus chemotherapy lived almost 5 months longer than patients receiving chemotherapy alone. Women taking iniparib were also more likely to see their tumors shrink.

While these findings are very encouraging, the study was small (123 patients participated) and only a phase II trial. A larger phase III study is now underway to try to confirm these findings.
 

For more information, see Breast Cancer: Detailed Guide.

Reviewed by Members of the ACS Medical Content Staff