Lurbinectedin in FET-Fused Tumors

This study is testing a drug called lurbinectedin in patients with rare cancers that have a specific genetic feature called a FET gene fusion — including Ewing sarcoma (a bone and soft tissue cancer) and other solid tumors with related gene rearrangements. These cancers have come back or stopped responding to standard treatments. The trial has two phases: a dose-finding phase and an efficacy-testing phase focused on Ewing sarcoma. **You may be eligible if:** - You are 10 years or older - Your cancer has returned or stopped responding to standard treatment - Your tumor has been confirmed to have a FET gene fusion (involving EWSR1, FUS, or TAF15 genes) by genetic testing - You are physically functional enough to carry out self-care activities (ECOG 0-1, or Lansky score at least 70 for children under 16) - You have at least one measurable tumor on imaging within the past 28 days **You may NOT be eligible if:** - Your cancer has not been confirmed to have a FET gene fusion - Your overall health or organ function does not meet the study's requirements - You are unable to tolerate the study treatment based on medical evaluation Talk to your doctor to see if this trial is right for you.