Amsacrine is primarily used in the treatment of acute leukemia, particularly acute myeloid leukemia (AML). It functions as an antineoplastic agent by intercalating into DNA and inhibiting topoisomerase II, which disrupts DNA replication and transcription, ultimately leading to cancer cell death. This makes it a valuable component in chemotherapy regimens for patients with refractory or relapsed leukemia. It is often administered intravenously under medical supervision due to its potent cytotoxic effects. Additionally, amsacrine is sometimes used in combination with other chemotherapeutic agents to enhance its efficacy in combating aggressive forms of cancer. Its use requires careful monitoring due to potential side effects, including myelosuppression and cardiotoxicity.