Phase II study of vinorelbine and capecitabine as first-line treatment for metastatic breast cancer.

Abstract

e12004 Background: Vinorelbine (V) and capecitabine (C) are likely to have a synergisitic interaction. Vinorelbine upregulates thymidine phosphorylase; a key enzyme in the conversion of capecitabine to active 5-FU in tumor tissue. Available phase II clinical data reports response rates ranging from 48-70% in first line metastatic breast cancer (MBC) for this combination. We evaluated the efficacy and safety of vinorelbine plus capecitabine in patients with MBC relapsing after adjuvant anthracycline based treatment. Methods: Sixty patients were enrolled between Oct 2008 through Dec 2010. All patients had measurable MBC relapse after adjuvant anthracycline and/or taxanes, WHO PS < 2, adequate bone marrow, renal and hepatic functions. Patients received intravenous vinorelbine 25 mg/m2 on day 1 and 8 and oral capecitabine 1000 mg/m2 bid on days 1 to 14, cycles to be repeated every 3 weeks. Patients with PD went off the study while those with CR, PR or SD continued treatment for a maximum of 8 cycles. Results: Median age 54 years (range 35-67 years), Median WHO PS 0 (range 0-1). Previous adjuvant therapy anthracycline (100%) and hormone therapy (60%). Median disease free interval was 6 months. Main metastatic sites were lung (40%), liver (25%), bone (40%) skin (35%), and lymph nodes (35%). Twenty five percent of patients had one metastatic site, 60% had two sites, 10% had three sites and 5% had more than three sites. The total number of cycles delivered was 441 with a median number of cycles/patients of 7 (range 3-8). An objective tumor response was achieved in 36 pts (60%), complete response (CR) in 6 pts (10%), 12 pts (20%) had stable disease (SD). After a follow up period of 6-36 months, the median time to progression and median survival were 14 and 23 months, respectively. No WHO G4 toxicities were noted, 3 pts (5%) developed G3 neutropenia and one patient (1.7%) developed G3 hand and foot syndrome. G2 anemia, neutropenia and diarrhea were reported in 2 pts (3.3%), 3 pts (5%) and 6 pts (10%), respectively. Conclusions: The combination of vinorelbine and capecitabine showed significant efficacy and mild toxicity as a first-line treatment for patients with metastatic breast cancer after failure of adjuvant anthracycline based therapy.