Intravenous or oral vinorelbine plus capecitabine as first-line treatment in HER2- metastatic breast cancer: joint analysis of 2 consecutive prospective phase II trials

Abstract

Background: The purpose of this study was to assess the activity and safety of the combination of vinorelbine (VNR) and capecitabine (CAP) as first-line treatment in HER2-negative (HER(-)) metastatic breast cancer (MBC).

Patients and methods: Patients (42) enrolled in trial A received intravenous (i.v.) VNR 25 mg/m2 on days 1 and 8 of a 21-day cycle combined with CAP 1000 mg/m2 twice daily for 14 consecutive days followed by 1 week of rest. Trial B (46 patients) followed trial A when the oral formulation of VNR became available at our institution. Patients received oral VNR (60 mg/m(2) on days 1-8) combined with the same CAP schedule as in trial A.

Results: The response rate (RR) in trial A was 73.2% (95% confidence interval [CI], 56.4-82.8), including 12.2% complete responses (CRs). Clinical benefit was achieved in 78% of patients (95% CI, 63.2-87.9). In trial B, overall RR was 76% (95% CI, 62.0-86.0), with 13% CRs and clinical benefit of 80.4% (95% CI, 66.8-89.3). In trial A, median progression-free survival (PFS) was 8.2 months (range, 6-14+ months) and median overall survival (OS) was 32.4 months (range, 17-36+ months). In trial B, median PFS and OS were 8.8 months (range, 8-21+ months) and 34.3 months (14-39+ months), respectively. Treatment-related toxicity was manageable. Quality of life assessment showed a statistically significant difference regarding body image (p = .001), sexual functioning (p = .02), and future perspectives (p = .03) in women receiving chemotherapy fully by the oral route.

Conclusion: This joint analysis shows that both tested schedules can produce high objective RRs with encouraging PFS, manageable toxicity profile, and suggested benefit on some aspects of quality of life for the fully oral combination.