Amsacrine (m-AMSA): a new antineoplastic agent. Pharmacology, clinical activity and toxicity.

The synthetic aminoacridine derivative amsacrine (m-AMSA) is capable of preventing DNA from serving as a template in replication and DNA synthesis. This mechanism of action is similar to that of anthracyclines, but clinical evidence suggests the lack of cross-resistance. The recommended dosage in patients with solid tumors is 90-120 mg/m2 intravenously every 3-4 weeks. Despite the initial encouraging reports from experimental models, m-AMSA has shown no real impact in the treatment of patients with a wide variety of solid tumors. In relapsed acute nonlymphocytic leukemia, 20-30% of patients will achieve complete remission. An increased remission rate is obtained when m-AMSA is combined with other agents, especially with high-dose cytosine arabinoside, with a complete remission rate of 50-60% in relapsed patients. Currently, several phase III trials are evaluating m-AMSA combinations against daunorubicin-containing regimens in patients with previously untreated acute leukemia. The potential role of these regimens in this disease remains to be defined.