Efficacy and safety of weekly oral vinorelbine (NVBO) as single agent in first- or second-line metastatic breast cancer (MBC).

Abstract

e11545 Background: NVBO has shown high activity and good safety profile when given as single agent chemotherapy (CT) for MBC. Oral CT formulations allow maintenance of quality of live and minimal interference with a normal lifestyle. Methods: Main inclusion criteria for this retrospective study were: Histologically or citologically confirmed MBC, no more than 1 prior CT line for MBC; prior (neo)adjuvant CT, hormonetherapy or radiotherapy allowed; adequate bone marrow, kidney and liver function. The study protocol was approved by an ethics committee. Data was collected from patients (p) treated between Apr/2006 and Dec/2010 with NVBO 60 mg/m2 weekly until progression or unacceptable toxicity. 70 patients fulfilled the inclusion criteria. Patient’s characteristics were: Median age, 65 years (range 38-82); >75 years old, 20%; ECOG PS 0-1 in 91% p and PS 2 in 9%; ER+ &/or PR+, 41 p (59%); >2 metastatic sites in 61%; prior (neo)adjuvant CT in 48 p (69%); prior hormonotherapy, 44 p (63%). Measurable disease in 68 p (97%). 1 p received trastuzumab concomitantly. Results: Median number of administrations (a) 11 (range 2-36). 1st/2nd line: 41%/59%. We analyzed 923 a. Dose delayed or reduced due to hematological toxicity in 2.7% a, related non-hematological toxicity in 0.3% a. Dose was reduced in 1% a. Hematological toxicities (%a): neutropenia grade (g) 3, 0.8%; febrile neutropenia 1 p who died due to septic shock after 9 a. Non-hematological toxicities (%a): pain g 3-4, 0.5%; constipation g 3-4, 0.3%; ileus paraliticus g 3, 0.1%; infection g 3, 0.1%; nausea/vomiting g4, 0.1% . 68 p were evaluable for response. 1 CR (1.5%), 19 PR (27.9%) and 16 SD (23.5%) were reported. Objective response (OR) rate 29.4% [CI 95%: 19%-41.7%]. Median progression free survival 4 m [CI 95%, 2.3-5.8]. Median survival has not been reached at the time of analysis. Conclusions: Our findings confirm the consistently produced clinically meaningful efficacy of single agent NVBO for MBC. We observed a favorable safety profile with a particular low incidence of myelosupression and alopecia. We consider that oral vinorelbine is a suitable 1st or 2nd-line treatment for convenient administration in an outpatient environment in selected p with MBC.