Tafasitamab and Lenalidomide as First Salvage Therapy for Residual Large B Cell Lym

This study is testing tafasitamab (an immunotherapy) combined with lenalidomide (a targeted cancer drug) for adults with large B-cell lymphoma who still have residual cancer after receiving CAR-T cell therapy with axicabtagene-ciloleucel. **You may be eligible if...** - You are 18 or older with large B-cell lymphoma (including DLBCL and related types) - You still have measurable cancer on a PET scan taken 21–60 days after your CAR-T cell infusion - You are in reasonably good health (ECOG 0–2) with adequate organ and bone marrow function - You have an oxygen level above 92% on room air **You may NOT be eligible if...** - You have cancer that has spread to the brain or spinal fluid - You have an uncontrolled active infection - You have a history of autoimmune disease requiring treatment in the past 2 years - You have a severe allergy to lenalidomide or tafasitamab - You are currently on or recently completed another investigational treatment (within 4 weeks) - You are pregnant or plan to become pregnant Talk to your doctor to see if this trial is right for you.