Safety Study in Subjects With Metastatic Breast Cancer Who Progressed After Taxanes Treatment.

Despite these initial positive signals in recent statistics, breast cancer continues to claim a substantial number of lives approximately 500,000 deaths worldwide in 2005 Thus the current treatment paradigm - surgery, radiation and systemic chemo and or hormonal therapy and biological therapies -still fails to cure a significant number of women with early breast cancer and new treatment strategies are needed to improve current results both in early and advance disease. Recurrent or metastatic breast cancer is an incurable malignancy with a median survival of 20-24 months \[Hortobagyi , 1998\] and this has not changed significantly over the last decade with fewer than 20% of patients still alive at 5 years after a diagnosis of recurrence. Although there have been small improvements in survival with the new therapies, metastatic breast cancer remains an incurable and, ultimately, fatal disease. The introduction of novel combination therapies have the potential to target different pathways in the cancer cell, leading to improved efficacy. Further studies to optimize combination therapy, while ameliorating AEs, are critically important to patients with metastatic breast cancer. Lapatinib is an oral tyrosine kinase inhibitor which potently inhibits both EGFR and HER2\[Spector, 2005\]. Lapatinib in combination with capecitabine is approved in more than 20 countries for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2. All patients in the study leading to the lapatinib approval had received prior therapy including an anthracycline, a taxane, and trastuzumab. The relevance of the HER2/neu target in breast cancer, combined with the promising preclinical and clinical data regarding the use of lapatinib, provide the rationale for a formal evaluation of this agent combined with other non taxane agents as gemcitabine or vinorelbine after progression on taxanes and trastuzumab based therapies in metastatic disease setting as the