Vinorelbine. A review of its pharmacological properties and clinical use in cancer chemotherapy.

Vinorelbine is a semisynthetic vinca alkaloid with a broad spectrum of antitumour activity. The drug is effective as a single agent in inoperable/advanced non-small cell lung cancer (NSCLC), producing objective response rates of about 15 to 30%, and as first-line or later chemotherapy for metastatic spread in advanced breast cancer. Combining vinorelbine with standard chemotherapeutic regimens improves response rates in these indications compared with vinorelbine monotherapy: in NSCLC response rates increase to 30 to 50% when vinorelbine is administered with cisplatin. Importantly, survival was prolonged by a further 9 weeks with this combination in a trial in > 600 patients with NSCLC. Comparative trials evaluating vinorelbine in women with advanced breast cancer are few at present. However, results suggest greater efficacy for vinorelbine than for melphalan as second-line chemotherapy, and similar efficacy for vinorelbine plus doxorubicin compared with doxorubicin plus 2 other drugs as first-line chemotherapy. Vinorelbine has tended to yield superior response rates when compared with vindesine, and appears to have greater haematological toxicity (i.e. granulocytopenia) but less neurological toxicity (peripheral neuropathy, constipation, loss of deep tendon reflexes) than this agent. Myelosuppression is the most frequent cause of vinorelbine treatment delay or dose reduction. Other consequences of vinorelbine therapy are those typically seen with antineoplastic agents, such as diarrhoea, nausea and vomiting, and alopecia. However, these are rarely severe. Early clinical investigations indicate that the antitumour effects of vinorelbine in other malignancies including ovarian carcinoma, lymphoma and head and neck cancer warrant further exploration, as does the efficacy of the drug relative to standard approaches and its possible beneficial effects on quality of life of cancer patients. Clarification is also required of the feasibility of an oral dosage form, which in preliminary investigations has shown some efficacy in NSCLC, but a variable response rate and high incidence of gastrointestinal disturbances in women with breast cancer. Thus, vinorelbine as a single agent or combined palliative therapy is effective against advanced NSCLC, and as first- or second-line chemotherapy in advanced breast cancer. This semisynthetic vinca alkaloid has a manageable tolerability profile and potential for use in other malignancies and as an oral formulation. With these attributes, vinorelbine is a valuable option which extends the range of treatments available for these difficult-to-treat malignancies.