Phase II trial of oral vinorelbine for the treatment of metastatic breast cancer in patients ≥65 years of age: An NCCTG study

Background: A one-stage phase II trial was conducted to assess the tumor response rate and toxicity profile of single agent oral vinorelbine as first or second-line chemotherapy for women at least 65 years of age with metastatic breast cancer. Patients and methods: Twenty-five patients with metastatic breast cancer aged ≥65 years of age were enrolled to receive oral vinorelbine on a weekly basis. The oral vinorelbine was given at 60 mg/ m² weekly for the first four doses and was increased to 70 mg/ m² for the subsequent administrations if there was no grade 4 neutropenia or no more than one episode of grade 3 neutropenia. Therapy was continued until progression or intolerable toxicity. Results: Twenty-five patients were included and evaluable for analysis. One patient (4%) achieved a partial response (PR) that lasted for more than 13 months. Two additional patients remained stable for at least 6 months for a clinical benefit rate (PR + stable disease) of 12%. The 1-year survival rate was estimated to be 48% (95% CI 30% to 74.5%). Median time to progression was estimated to be 4.7 months (95% CI 2.0-5.5 months) and the 9-month disease progression-free rate was estimated to be 8% (95% CI 30.9% to 74.5%). The treatment was fairly well tolerated with grade 3 neutropenia in 12.5%, fatigue in 12.5% of the patients, and grade 2 neuromotor and neurosensory toxicities in 12.5% and 8.3%, respectively. Conclusion: Oral vinorelbine as a single agent at these dose and schedule in this population of women ≥65 years is well tolerated but has a low level of objective efficacy for the treatment of metastatic breast cancer.