Selinexor (KPT-330) demonstrates anti-tumor efficacy in preclinical models of triple-negative breast cancer

BACKGROUND: Selinexor (KPT-330) is an oral agent that has been shown to inhibit the nuclear exporter XPO1. Given the pressing need for novel therapies for triple-negative breast cancer (TNBC), we sought to determine the antitumor effects of selinexor in vitro and in vivo. METHODS: ) and to test the effects in combination with chemotherapy. In vivo efficacy was tested both as a single agent and in combination therapy in TNBC patient-derived xenografts (PDXs). RESULTS: > 1000 nM, range 40 to >1000 nM; P = 0.017). In multiple TNBC cell lines, selinexor was synergistic with paclitaxel, carboplatin, eribulin, and doxorubicin in vitro. Selinexor as a single agent reduced tumor growth in vivo in four of five different TNBC PDX models, with a median tumor growth inhibition ratio (T/C: treatment/control) of 42% (range 31 to 73%) and demonstrated greater antitumor efficacy in combination with paclitaxel or eribulin (average T/C ratios of 27% and 12%, respectively). CONCLUSIONS: Collectively, these findings strongly suggest that selinexor is a promising therapeutic agent for TNBC as a single agent and in combination with standard chemotherapy.