CA102N is a novel anticancer product designed to deliver its payload (Nim) to cells via the CD44 receptor. CA102N is currently in Phase 1 clinical trial for the treatment of metastatic colorectal cancer (mCRC). The major target of CA102N is the PI3K/Akt/mTOR cell signaling pathway, one of the most significantly deregulated pathway in several human cancers, including breast cancer. In the present study, the anticancer activity of CA102N was assessed on cell signaling, cell proliferation, and apoptosis in vitro in MDA-MB-231 human breast cancer cells. The antitumor efficacy was also tested in vivo in xenograft mice. We demonstrated that CA102N selectively inhibited MDA-MB-231 breast cancer cell growth and proliferation in vitro Administration of CA102N at 4.6mg/kg in xenograft mice resulted in effective tumor growth inhibition (TGI, 80%) with no apparent treatment-related toxicity. Suppression of PI3K/Akt downstream signaling was also detected in vitro. These results suggest that CA102N may represent a new potential treatment option for breast cancer. Combinations therapies and schedules are currently being explored in mice. to maximize the basis for its advancement therapy into the clinic.