A phase III randomized trial of niraparib versus physician’s choice in previously treated, HER2-negative, germline-BRCA mutated breast cancer patients: Intergroup study EORTC-1307-BCG and BIG5-13.

TPS659 Background: Germline mutations of BRCA1/BRCA2 genes are a cause of hereditary breast or ovarian cancer. Cancers arising in women with germline BRCA1/BRCA2 mutations are defective in DNA repair, and BRCA deficient cancer cells are hypersensitive to PARP inhibitors (Bryant et al., 2005;Farmer et al., 2005). Niraparib is a potent,selective inhibitor of PARP-1 and PARP-2 that demonstrated activity in BRCA1 or BRCA2 mutated cancer cell lines. Responses have been reported with Niraparib in women with BRCA1.2 related breast and ovarian cancer. (Michie et al, 2013). Methods: Patients with HER2 negative metastatic breast cancer (306), with centrally confirmed BRCA1 or BRCA2germline mutations, will be randomized 2:1 open-label study, to either niraparib 300mg (3x 100 mg niraparib capsules) administered orally QD continuously or physician’s choice of single-agent chemotherapy (eribulin, vinorelbine, capecitabine or gemcitabine) administered in 3 weekly cycles. Patients must have received prior therapy that in...