The Efficacy and Safety of Anlotinib Combined With Fulvestrant in Patients With Advanced Breast Cancer

The management of HR-positive, HER2-negative metastatic breast cancer includes endocrine monotherapy or combination regimens, both with benefit diminishing as resistance develops. Nowadays, various studies have demonstrated that estrogen interacts with many angiogenic pathways and is an important mechanism for resistance leading to the question of whether combination with antiangiogenesis and antiestrogen therapies could be an appropriate therapeutic modality. Anlotinib is a novel multi-target tyrosine kinase inhibitor that effectively inhibit VEGFR, FGFR, PDGFR, c-KIT, c-MET and RET. Previous studies have proven the efficacy of both anlotinib monotherapy and combination regimens in advanced breast cancer. This phase II study aims to preliminarily evaluate the efficacy and safety of anlotinib combined with endocrine therapy.

This study is a prospective, single-arm, open-label, phase II clinical trial. The secondary endocrine-resistant is defined as disease relapse within 12 months after at least 24 months endocrine adjuvant therapy, or disease progress after at least 6 months endocrine salvage therapy. Eligible patients were treated with oral anlotinib plus intramuscular fulvestrant till disease progression or intolerant toxicity. In the part of statistical analysis, 40 patients are required to have a 80% power to detect significant improvement in median progression-free survival from 5.8 (fulvestrant alone) to 10 (fulvestrant combined with anlotinib) months, if tested at a two-sided significance level of α=0.05.