Phase II study of apatinib plus vinorelbine, a novel combination of all-oral regimen in heavily pretreated patients with metastatic HER2-negative breast cancer.

Abstract

TPS1123 Background: Antiangiogenic therapy in combination with chemotherapy is effective in control advanced breast cancer(ABC). Apatinib is an oral, highly potent tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 2(VEGFR-2). Phase II clinical trials of Apatinib single agent had presented objective response and manageable toxicity in heavily pretreated, metastatic breast cancer. The median progression free survival (PFS) and median overall survival (OS) of single agent in both triple-negative and non-triple-negative breast cancer were 3.3-4.0 months and 10.3-10.6 months, respectively. The overall response rate and disease control rate (DCR) reached 16.7% and 66.7%, respectively. This all-oral phase II study aims to investigate the efficacy and safety of the oral vinorelbine-Apatinib combination in pre-treated metastatic breast cancer(MBC). Methods: This single arm prospective study enrolled patients with HER2(Human epidermal growth factor receptor-2 ) negative advanced breast cancer, pretreated with anthracycline and taxanes, and who failed in the metastatic setting at least one prior chemotherapy regimen. The estimated Enrollment was 40 patients.The primary end point of this study was PFS. Secondary end points included objective response rate (ORR), DCR, OS and safety. Patients were treated with apatinib 500/425mg daily plus oral vinorelbine 60-80 mg/m2 day1,8,15 every 3 weeks/cycle. Starting doses of Apatinib were chosen according to age, weight and patient status. Patients eligible were evaluated by CT or MRI scan at baseline and every 2 cycles (6 weeks) there after until disease progressed. Adverse events (AEs) were assessed and graded in accordance with the Common Terminology Criteria for AEs, version 4.0. Clinical trial information: NCT02768415.