Oral vinorelbine (Navelbine) in the treatment of advanced breast cancer.

Vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Médicament, Paris, France) has been formulated as a liquid-filled, soft gelatin capsule. Pharmacokinetic studies of this agent indicate that it has a large volume of distribution, a long terminal half-life, and a high clearance rate. The pharmacokinetics of vinorelbine are similar whether the drug is administered orally or intravenously. Oral vinorelbine has a low bioavailability, which may be due to a high first-pass effect. Preliminary results from two multicenter phase II trials of oral vinorelbine in patients with advanced breast cancer are presented. In one study of 98 advanced breast cancer patients aged 65 years and older with limited prior therapy, the response rate of oral vinorelbine was 24% (complete response, 5%; partial response, 19%). In a study of 131 heavily pretreated patients with advanced breast cancer, the response rate of oral vinorelbine was 11% (complete response, 0%; partial response, 11%). In both studies, oral vinorelbine was generally well tolerated. As with intravenous administration, neutropenia is common and neuropathy is infrequent. In contrast to intravenous administration, nausea, vomiting, and diarrhea are common. Based on these preliminary results, further clinical investigation of oral vinorelbine is warranted.