Amrubicin hydrochloride is primarily used in the treatment of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). It functions as a topoisomerase II inhibitor, preventing the enzyme from repairing DNA damage in cancer cells, leading to cell death. This makes it an effective chemotherapeutic agent for patients with advanced or recurrent lung cancer who have not responded well to other treatments. It is often administered intravenously in clinical settings. Additionally, its relatively favorable safety profile compared to some other chemotherapeutic drugs makes it a viable option for patients who may not tolerate more aggressive treatments. Research is ongoing to explore its potential in treating other types of cancer and to optimize its therapeutic efficacy.