Use a handheld device (tablet) at the trial site to answer questionnaires about your symptoms and your ability to do common activities in your daily life. Have a physical exam. Give blood and urine (pee) samples. If you are getting zilovertamab vedotin (Group 1), you will give multiple blood samples at some visits. For example, you may need to give a blood sample before and after getting zilovertamab vedotin, and then 4 hours after trial treatment. You will also have to return to the trial site 2 times in the 2 weeks after your first infusion of zilovertamab vedotin to have your blood drawn. Have an echocardiogram (ECHO) or multiple-gated acquisition (MUGA) Have an electrocardiogram (ECG). Have scans using computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or other tests. Have a bone marrow biopsy at the beginning of the trial. Have a tumor biopsy or give tumor tissue from an earlier biopsy at the beginning of the trial.