Yttrium-90 Labeled Anti-CD25 Monoclonal Antibody Combined With BEAM Chemotherapy Conditioning for the Treatment of Primary Refractory or Relapsed Hodgkin Lymphoma

This study tests a radioactive antibody treatment (Y-90 anti-CD25) combined with standard high-dose chemotherapy before a stem cell transplant in patients with high-risk Hodgkin lymphoma that has relapsed or not responded to initial treatment. The radioactive antibody targets a specific protein (CD25) found on Hodgkin lymphoma cells. **You may be eligible if...** - You are 18 or older and have confirmed Hodgkin lymphoma - Your lymphoma is high-risk: it relapsed quickly, came back after immunotherapy (PD-1 blockade or brentuximab), has spread outside lymph nodes, or you have B symptoms (fever, sweats, weight loss) - You have already had stem cells collected for transplant (at least 2 million CD34+ cells/kg) - You are in reasonably good health (Karnofsky score 70% or higher, life expectancy over 6 months) - Your kidney, liver, and heart function meet the study requirements **You may NOT be eligible if...** - Your lymphoma is not confirmed Hodgkin lymphoma - You have not yet had your stem cells collected - You have serious organ dysfunction (kidney, liver) - You have active infections or other serious illnesses Talk to your doctor to see if this trial is right for you.