RESUMEN
A late phase II clinical study (II) of a novel vinca alkaloid derivative KW-2307 (vinorelbine ditartrate) in advanced/recurrent breast cancer patients was performed at 22 institutions throughout Japan. An intravenous dose of KW-2307, 20 mg/m2, was administered once a week. Of the 60 patients enrolled in the study, 58 were eligible and 56 were evaluable. The response rate was 33.9% (19/56; 95% confidence interval: 21.8 to 47.8%) with one CR and 18 PRs. The response rate was as high as 37.0% (17/46; 95% confidence interval: 23.2 to 52.5%) when KW-2307 was used as a first-line chemotherapy for advanced/recurrent disease. The most common adverse event was myelosuppression including leukopenia in 96.4% (54/56) and neutropenia in 94.3% (50/53). Other events observed were increased GOT in 51.8% (29/56), increased GPT in 55.4% (31/56), LDH increased in 50.0% (27/54), serum total protein decrease in 39.3% (22/56), anorexia in 41.1% (23/56), nausea and vomiting in 66.1% (37/56), constipation in 30.4% (17/56), alopecia in 33.9% (19/56) and general fatigue in 46.4% (26/56). None of them were serious. This study demonstrated that KW-2307 was an effective and safe treatment for advanced/recurrent breast cancer patients.