A phase II study of foretinib in triple-negative, recurrent/metastatic breast cancer: NCIC CTG trial IND.197 (NCT01147484).

1036 Background: Met, a receptor tyrosine kinase, is preferentially expressed in basal-like compared to luminal breast cancer. In murine models, overexpression of the oncogenic Met receptor transgene induces tumors with human basal gene expression characteristics supporting Met inhibition as a treatment strategy for triple negative (TN) breast cancer. Foretinib is an oral multi-kinase inhibitor of Met, RON, AXL, TIE-2 and VEGF receptors with anti-tumor activity in advanced HCC and papillary renal cell cancer. Methods: Patients (pts) with TN breast cancer and 0-1 prior regimens for metastatic disease received daily foretinib 60 mg po in a 2-stage single arm trial. Primary endpoints were objective response and early progression rates per RECIST 1.1. Tumor samples were centrally reviewed to confirm ER/PR/HER2 status and for correlative studies including Met, PTEN and EGFR expression. Stage 1 accrual required 23 response-evaluable Met unselected patients with accrual continuing if >/= 1 response or < 17 early...