Due to progress of studies on the molecular and genetic basis of cancer and cellular signaling pathways, targeted therapy has been developed for various cancer treatments. A Gynecologic Oncology Group study found 44% of advanced endometrial cancer had HER>=2+ and the ratio of HER2:chromosome 17 (CEP17) >=2. Another study showed that HER>=2+ was seen in 47% of carcinosarcoma. These evidences indicated HER2 gene amplification and HER2 overexpression occur in endometrial cancer and carcinosarcoma, especially in those of high grade and recurrence. Lapatinib (L), an oral inhibitor of both EGFR(epidermal growth factor receptor) and HER2(human epidermal growth receptor), has been shown to be an effective treatment in HER2/neu overexpressing metastatic breast cancer. Ixabepilone is a semisynthetic analog of the natural product epothilone B, and recently has been approved by US Food and Drug Administration as a treatment option in metastatic breast cancer. It was also observed that lapatinib + ixabepilone killed more breast tumor cells than trastuzumab + paclitaxel in vitro. Two GOG(Gynecologic Oncology Group) studies had reported that weekly Ixabepilone as 2nd-line chemotherapy provided a similar RR to 3-weekly regimen of 14.3% in platinum- and taxane-resistant epithelial ovarian cancer with less severe toxicities. The combination of lapatinib and ixabepilone is expected to become an effective treatment for recurrent endometrial cancer and carcinosarcoma, but the ideal dose is yet to be surveyed.