Lurbinectedin is a newer cancer medicine. Doctors are studying it to see how well it works for soft tissue sarcomas like leiomyosarcoma. It is approved by the FDA to treat small cell lung cancer, but it is not approved to treat sarcoma. Using lurbinectedin and doxorubicin together is also not FDA approved. This means it is considered investigational. If you are interested in this study, we will first check if you are a good match. We will ask you some questions and have you do some tests. If you choose to join, you will be put into one of three groups by chance, like flipping a coin. One group will get 50 mg of doxorubicin followed by 2.2 mg of lurbinectedin every three weeks for up to 9 cycles. Another group will get 25 mg of doxorubicin followed by 3.2 mg of lurbinectedin every three weeks for up to 18 cycles. For both groups, the medicines will be given through a central catheter, which is a soft tube placed in a vein in your neck, or through a vein in your arm. You will also get granulocyte colony-stimulating factors (G-CSF) about 1 to 3 days after lurbinectedin. G-CSF helps your body make more white blood cells called neutrophils, which help protect you from infections. The third group will get 75 mg of doxorubicin every three weeks for up to 6 cycles. This would be considered the usual standard of care. This drug will also be given through a central catheter or a vein in your arm. You will have 11 visits during the study. At these visits, you may have a physical exam, and the study team may check your heart rate, blood pressure, and temperature. They will make sure you are healthy enough before giving any study treatment. Blood samples will be taken before treatment for routine tests and to see how your body processes lurbinectedin. You will also have different tests and scans to see how your cancer is changing. An ECHO will be done at certain times during the study to check on your heart. Every 6 weeks, you will fill out surveys about your health and quality of life. The study team will ask about any side effects from the study treatment and other medicines you are taking. You will continue to get the study treatment if your cancer is under control, your study doctor thinks it is safe, and you still want to stay in the study. You will not be paid to be in the study, but you may get help with travel costs. You and your insurance will need to pay for regular medical care, tests, and treatment.

Who can Participate

You may be able to join this study if you are an adult with metastatic leiomyosarcoma that cannot be removed by surgery. You can join if you have had chemotherapy in the past for adjuvant or neoadjuvant treatment, as long as it did not include anthracyclines. You must not have received any treatment for metastatic cancer before, and you must not have had anthracycline medicines. You cannot join this study if you have been treated with anthracyclines, lurbinectedin or trabectedin, you have low grade (grade I) leiomyosarcoma, you have had radiation therapy, or you only have one tumor that can be measured. More information is available on ClinicalTrials.gov. Your doctor or a study team member will review these requirements with you.

Study ID

More information available at ClinicalTrials.gov: NCT06088290