This study is testing if it's safe to use two treatments together for lung cancer that has spread. **Lurbinectedin** is a medicine that kills cancer cells by stopping them from making proteins they need to grow. **Palliative radiotherapy** is a type of radiation that helps with cancer symptoms. The study wants to know if using these treatments at the same time works better than using them alone. Researchers will check if there are more side effects when they are used together.

• The study lasts about 21 days with follow-ups up to 12 months.
• Patients receive radiation treatment daily and lurbinectedin every 21 days.
• Participants must agree to certain safety rules, like using birth control.

For patients to join, they need to be over 18, have specific blood test results, and have cancer that has spread. They cannot be pregnant or breastfeeding. This study helps doctors learn if combining the treatments is safe and effective.