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.

PURPOSE

Metronomic 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.

METHODS

VinoMetro 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.

RESULTS

Between January 2017 and April 2019, nine 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.

CONCLUSION

VinoMetro (AGO-B-046) was closed early after nine 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 REGISTRATION

ClinicalTrials.gov Identifier: NCT03007992; December 15, 2016.