Apatinib Combined With Oral Etoposide in Metastatic HER2 Negative Breast Cancer

Apatinib is an orally administered second-generation blocker of the phosphorylation of the tyrosine residues within the intracellular domain of VEGF receptor 2 (VEGFR2). A prospective, open label, phase II multicenter trial of apatinib in heavily pretreated patients with metastatic triple-negative breast cancer demonstrated that the daily dose of apatinib 500 mg/day is active in pretreated metastatic TNBC with encouraging rates of disease stabilization and PFS. Etoposide is a highly active drug in the treatment of MBC, both as a single agent or in combination regimens, and is well tolerated, with a low incidence of severe toxicity. Clinical trials demonstrated oral Etoposide provided comparable effectiveness to iv Etoposide. and oral availability allows using different schedules. The NCCN guideline introduces that combination chemotherapy is one of the standard treatment options in metastatic breast cancer, especially in patients with visceral metastases and/or need of rapid symptom or disease control. Theoretically, anti-angiogenesis regimen combined with chemotherapy may present increasing therapeutic effect. Related researches are urgently needed to find optimal combined therapy. The hypothesis of this study is to discover if the all-oral therapy with apatinib plus oral Etoposide can shrink or slow the growth of pretreated HER2 negative breast cancer. The safety of the combination will also be studied. Patients physical state, symptoms, changes in the size of the tumor, and laboratory findings obtained while on-study will help the research team decide if this combination is safe and effective in pretreated HER2 negative metastatic breast cancer patients.