In two separate studies, researchers found that two new drugs belonging to a group of drugs called PARP inhibitors may help treat some types of breast cancer. PARP inhibitors stop cancer cells from repairing damage from chemotherapy, which may make cancer cells more sensitive to chemotherapy. These studies include:

• The use of a PARP inhibitor called BSI-201 to treat triple-negative breast cancer that has spread to other parts of the body. Triple-negative breast cancer cannot be treated with hormone therapy or drugs that block HER2 (a protein found on some types of breast cancers). This study showed that women with this type of breast cancer who received BSI-201 and chemotherapy lived about four months longer than women who received only chemotherapy. In addition, the time it took for the cancer to grow and spread was also more than four months longer for women who received BSI-201 and chemotherapy. Women who received BSI-201 were four times more likely to have their tumors stop growing or shrink than women who did not receive the drug.
• The use of a PARP inhibitor, called olaparib, to treat persistent, advanced breast cancer with mutated (changed) BRCA genes. This study showed olaparib slowed tumor growth for 40% of patients who received the drug.

What this means for patients

These studies show that PARP inhibitors may be a new type of chemotherapy that could be used to treat breast cancer, particularly those that are difficult to treat. However, more research is needed to find out how they can be best used to treat breast cancer. Patients who received BSI-201 had few side effects. The most common side effects for olaparib were mild fatigue, nausea, and vomiting. These drugs are not available outside of a clinical trial

What to Ask Your Doctor

• What type of breast cancer do I have?
• What are my treatment options?
• What clinical trials are open to me?

For More Information

Cancer.Net Guide to Breast Cancer [1]

ASCO Answers Fact Sheet: Breast Cancer [2]

Clinical Trials [3]