A drug used to treat breast cancer that has spread or that has come back within 6 months after chemotherapy. It is also being studied in the treatment of newly diagnosed breast cancer and other types of cancer. Protein-bound paclitaxel is a type of mitotic inhibitor. Also called ABI-007, Abraxane, nanoparticle paclitaxel, and paclitaxel albumin-stabilized nanoparticle formulation.