Methods for treating cancer (e.g., breast cancer, lung cancer, pancreatic cancer, primitive neuroectodermal tumors, lung cancer, ovarian cancer, endometrial cancer, pharyngeal cancer, esophageal cancer, and sarcoma) in a subject (such as an human patient) in need thereof by administering eribulin (e.g., eribulin mesylate, i.e., E7389, Halaven) in combination with one or more mammalian target of rapamycin (mTOR) inhibitors (e.g., everolimus, ridaforolimus, and temsirolimus), and kits therefor are provided.