Reparixin seems to be a good candidate for use in breast cancer patients because of its very acceptable toxicity profile shown in the Phase I and II clinical trials conducted so far, along with its observed activity in vitro against breast cancer cell lines and in vivo in tumor xenografts in mice. It potentially addresses another therapeutic target in metastatic disease. The current pilot study thus aims at exploring the safety and PK profile of orally administered reparixin in HER-2 negative metastatic breast cancer patients and its effects on breast CSC markers.