Vinorelbine tartrate

Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.

Navelbine (ASTA Medica)

10 mg/mL in 1 mL and 5 mL vials

Indication: breast cancer and non-small cell lung cancer

Chemotherapy with several drugs has an increasing role in breast cancer.1 Vinorelbine adds to the options available for advanced disease after the failure of other treatments. It is a semi-synthetic alkaloid resembling vinblastine.

Vinorelbine was given to 115 patients with advanced breast cancer which was resistant to chemotherapy with anthracycline. There was a response in approximately 16% of the patients, with a duration of approximately 32 weeks.

The drug is diluted and given by slow injection or infusion once a week. High concentrations occur in the lungs and vinorelbine is highly bound to platelets and lymphocytes. The drug is metabolised by the liver so the dose must be adjusted if liver function is impaired. Vinorelbine has a half-life of 28-43 hours.

As the drug is thought to inhibit mitosis, some of its adverse effects are predictable. Neutropenia occurs in about half the patients. Subsequent doses should be reduced or delayed according to the neutrophil count. Anaemia and thrombocytopenia can also occur. The vinca alkaloids have been associated with peripheral neuropathy, but this may be less pronounced with vinorelbine. Autonomic neuropathy may cause constipation. Although over 25% of patients develop nausea, severe vomiting does not occur often enough to warrant routine use of serotonin receptor antagonists. Injection site reactions are a problem. The vein should be flushed through after vinorelbine is given. Other adverse effects include chest pain, shortness of breath and fatigue.

Although vinorelbine has relatively less toxicity than some other drugs, its role will require further study. For example, how does vinorelbine compare with the taxanes in advanced breast cancer?

Vinorelbine has been studied in other cancers and has been approved for use in non-small cell lung cancer. When vinorelbine is given alone to patients with small cell lung cancer, the response rate is 14%. If the patients are given vinorelbine with cisplatin, the response rate increases to 28-43%, but the combination is likely to be more toxic. Although survival is said to be increased, non-small cell lung cancer has a very poor prognosis. Any increase in life expectancy will be measured in weeks as the median survival time for untreated disease is less than 6 months.