PARP Inhibitors in Triple-Negative Breast Cancer

The treatment of patients with triple-negative breast cancer (TNBC) remains a challenge, since very limited options are available following neoadjuvant therapy, even in early-stage disease, states Hope S. Rugo, MD. At this point, the only options available are chemotherapy. Some data suggest that TNBC may be more responsive to therapies that cause direct DNA damage, such as carboplatin and cisplatin. Ongoing trials are evaluating biomarker data that might help identify patients with TNBC who are likely to have better responses to this class of drugs.

TNBC has been found to be commonly associated with BRCA1/2 mutations, suggesting that it may be important to test for BRCA in the metastatic setting and in high-risk early stage disease, says Rugo. This remains particularly important, especially with the development of investigational PARP inhibitors for patients with TNBC.

There are several ongoing clinical trials evaluating four major PARP inhibitors, veliparib, olaparib, rucaparib, and talazoparib, in patients with TNBC who have had multiple lines of prior chemotherapy, including platinum-based agents. Additionally, there are clinical trials examining Notch antagonists in a subset of patients who have TNBC that overexpresses Notch, Rugo notes.