Safety and Efficacy of Systemic Allogenic NK Cells in R/R Neuroblastoma

This study is testing whether infusions of natural killer (NK) cells — immune cells taken from healthy donors — can safely and effectively fight neuroblastoma (a type of childhood cancer) that has stopped responding to standard treatments. **You may be eligible if...** - You have high-risk neuroblastoma that did not respond to standard induction chemotherapy (at least 4 cycles) - Your cancer has relapsed or progressed after a stem cell transplant or aggressive therapy - Your cancer is confirmed by pathology and/or bone marrow testing - You have measurable disease on imaging scans - Your expected survival is at least 6 months **You may NOT be eligible if...** - Your overall health and organ function are too poor to tolerate the treatment - You have an active serious infection or other condition that would interfere with treatment - You do not have measurable residual disease Talk to your doctor to see if this trial is right for you.