Oral metronomic vinorelbine combined with endocrine therapy in hormone receptor-positive HER2-negative breast cancer: SOLTI-1501 VENTANA window of opportunity trial.

ABSTRACT: BACKGROUND:The biological effect of oral metronomic vinorelbine (mVNB) alone or in combination with endocrine therapy in patients with hormone receptor-positive (HR+)/HER2-negative breast cancer has been scarcely addressed. METHODS:Postmenopausal women with untreated stage I-III HR+/HER2-negative breast cancer were randomized (1:1:1) to receive 3?weeks of letrozole (LTZ) 2.5?mg/day, oral mVNB 50?mg 3 days/week, or the combination. The primary objective was to evaluate, within PAM50 Luminal A/B disease, if the anti-proliferative effect of LTZ+mVNB was superior to monotherapy. An anti-proliferative effect was defined as the mean relative decrease of the PAM50 11-gene proliferation score in combination arm vs. both monotherapy arms. Secondary objectives included the evaluation of a comprehensive panel of breast cancer-related genes and safety. An unplanned analysis of stromal tumor-infiltrating lymphocytes (sTILs) was also performed. PAM50 analyses were performed using the nCounter®-based Breast Cancer 360™ gene panel, which includes 752 genes and 32 signatures. RESULTS:Sixty-one patients were randomized, and 54 paired samples (89%) were analyzed. The main patient characteristics were mean age of 67, mean tumor size of 1.7?cm, mean Ki67 of 14.3%, stage I (55.7%), and grades 1-2 (90%). Most baseline samples were PAM50 Luminal A (74.1%) or B (22.2%). The anti-proliferative effect of 3?weeks of LTZ+mVNB (-?73.2%) was superior to both monotherapy arms combined (-?49.9%; p?=?0.001) and mVNB (-?19.1%; p?

SUBMITTER: Adamo B 

PROVIDER: S-EPMC6751874 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature