Investigation Drug PARP Inhibitor for Triple-Negative Breast Cancer

breast cancer ribbon naked woman white

Breast cancer has many subtypes. One of the most aggressive is the so-called “triple negative” type. Here, the cancer cells do not have estrogen receptors (so we can’t target these receptors with drugs such as tamoxifen), progesterone receptors, or HER2 (thus drugs that target HER2 won’t work). Many patients with this aggressive subtype of breast cancer will receive chemotherapy, but the results are still typically worse than for the other subtypes. It is in this context that investigators introduced an innovative new way to test new cancer-fighting drugs.

The Study: The I-SPY 2 trial uses an adaptive design to move promising drugs forward in clinical development. In this Phase II study evaluating a novel targeted drug (veliparib) plus chemotherapy (carboplatin) for treatment before surgery, the odds of the tumor disappearing from the breast (under the microscope) were:

  • Chemotherapy alone 26%
  • Chemotherapy plus veliparib 52%

My Take: This study is remarkable for several reasons: 1) the novel design shows that we can start and conduct trials rapidly; 2) we can choose patients based on their cancer’s molecular fingerprint (profile), using drugs based on their targets. With such a design, we may be able to quickly eliminate drugs that are not promising, and advance better ones into higher level clinical trials. In this study, some PARP inhibitors (for example iniparib) didn’t work well, but others did (veliparib). Triple negative breast cancer is challenging, and the I-SPY 2 trial brings new hope. Phase III trials should better define how good veliparib really is. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

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Reference: Rugo, HS, et al. Veliparib/carboplatin plus standard neoadjuvant therapy for high-risk breast cancer: First efficacy results from the I-SPY 2 trial. 2013 San Antonio Breast Cancer Symposium. Abstract S5-02. Presented December 13, 2013.