YTS104 Cell Injection for the Treatment of Relapsed or Refractory Multiple Myeloma

This study is testing YTS104, a new CAR-T cell therapy (where your immune cells are reprogrammed to attack cancer), for people with multiple myeloma (a blood cancer) that has returned or stopped responding to other treatments. **You may be eligible if...** - You are 18–75 years old - You have relapsed or refractory multiple myeloma after at least 3 prior treatment lines - Prior treatments must have included a proteasome inhibitor (like bortezomib) and an immunomodulatory drug (like lenalidomide) - You have measurable disease - You have adequate organ function **You may NOT be eligible if...** - You have had a prior CAR-T cell therapy - You have active brain involvement from myeloma - You have serious heart, liver, or kidney problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.