Phase II Study of Metronomic Treatment With Daily Oral Vinorelbine as First-line Chemotherapy in Patients With Advanced/metastatic HR+/HER2- Breast Cancer Resistant to Endocrine Therapy: VinoMetro – AGO-B-046

Abstract

PurposeMetronomic chemotherapy (MCT) is an increasingly used treatment option in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced/metastatic breast cancer (MBC) after failure of endocrine-based therapies. MethodsVinoMetro was a multicentre, open-label, single-arm, phase II study of metronomic oral vinorelbine (VRL; 30 mg/day) as a first-line chemotherapy (CT) in patients with HR+/HER2- MBC after endocrine failure. The primary endpoint was the clinical benefit rate (CBR) at 24 weeks. ResultsBetween January 2017 and April 2019, 9 patients were enrolled. The CBR was 22.2% (90% confidence interval [CI] 4.1–55.0), p=0.211. The median progression-free survival (PFS) was 12.0 weeks (95% CI 11.3–12.7). Grade 3-4 adverse events (AEs) occurred in 22.2% of patients. One patient died of febrile neutropenia.ConclusionVinoMetro (AGO-B-046) was closed early after 9 patients and occurrence of one grade 5 toxicity in agreement with the lead institutional review board (IRB). Metronomic dosing of oral VRL in HR+/HER2- MBC as first-line CT after failure of endocrine therapies showed only limited benefit in this population.Trial registration number and date of registrationClinicalTrials.gov Identifier: NCT03007992; December 15, 2016