This clinical trial is focused on studying a type of cancer called metastatic leiomyosarcoma, which is a cancer that starts in smooth muscle tissue and has spread to other parts of the body. The study is testing a new treatment combination to see if it can help patients with this condition. The treatment being studied includes a drug called lurbinectedin, which is being tested in combination with another drug called doxorubicin hydrochloride. Doxorubicin hydrochloride is already used in cancer treatment, and this study aims to find out if adding lurbinectedin can improve outcomes for patients.

The purpose of the study is to determine if the combination of lurbinectedin and doxorubicin hydrochloride can help patients live longer without their cancer getting worse, compared to using doxorubicin hydrochloride alone. Patients participating in the study will receive these medications through an intravenous (IV) infusion, which means the drugs are given directly into a vein. The study will compare the effects of the combination treatment to the effects of doxorubicin hydrochloride alone, to see which is more effective as a first-line treatment for metastatic leiomyosarcoma.

Participants in the study will be randomly assigned to receive either the combination of lurbinectedin and doxorubicin hydrochloride or doxorubicin hydrochloride alone. The study will be conducted over a period of time, and patients will be monitored to see how their cancer responds to the treatment. The study will also look at the safety of the treatments and any side effects that may occur. This research is important to help find better ways to treat metastatic leiomyosarcoma and improve the quality of life for patients with this condition.