Optimizing lymphoDepletion to Improve Outcomes In Patients Receiving Cell Therapy With Yescarta

This study is testing different methods of preparing the immune system (called lymphodepletion) before a type of advanced immune cell therapy called CAR-T (specifically axicabtagene ciloleucel, or Yescarta) in people with a type of aggressive blood cancer called large B-cell lymphoma. The goal is to improve outcomes by optimizing the pre-treatment process. **You may be eligible if...** - You are 18 or older with relapsed or refractory large B-cell lymphoma (including DLBCL) - You have received at least 2 prior lines of treatment, including anti-CD20 therapy and an anthracycline (a type of chemotherapy) - You are otherwise eligible for standard CAR-T cell therapy - Your overall health and organ function are adequate (ECOG 0-1) - You have not had prior CD19-targeted therapy or allogeneic (donor) stem cell transplant **You may NOT be eligible if...** - You are HIV positive or have active hepatitis B or C - You have active brain involvement by lymphoma - You have had a heart attack, severe heart failure, or serious cardiac disease in the past 12 months - You have a history of severe autoimmune disease requiring immunosuppression - You have an uncontrolled active infection - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.