Mitoxantrone: a New Anticancer Drug with Significant Clinical Activity

Clinical studies using mitoxantrone, an anthraquinone, were begun in the United States in 1979. Subsequent phase II and III trials have shown that mitoxantrone has significant clinical activity in patients with breast cancer, acute leukemia, and lymphoma. The drug has antiviral, antibacterial, antiprotozoal, immunomodulating, and antineoplastic properties and is mutagenic in some animal systems. Its mechanism of action seems to involve both DNA intercalation and nonintercalative electrostatic interactions. The dose-limiting toxicity is myelosuppression when the drug is given on a single-dose, every-3-week schedule and mucositis when it is given daily for 5 days. Other toxicities include gastrointestinal and cardiac effects, the gastrointestinal toxicity being less severe and less frequent than that with the anthracycline anticancer drugs. Because of its low incidence of serious toxicities and effectiveness in treating certain solid tumors and leukemias, mitoxantrone is a promising new agent in the treatment of cancer.