RecruitingPhase 2Drug trialA Study of Glofitamab-based Treatment in People With Diffuse Large B-cell LymphomaThe researchers are doing this study to find out if the study treatment is an effective treatment that causes few or mild side effects in people with diffuse large B-cell lymphoma (DLBCL), high-grade B-cell lymphoma (HGBCL), or transformed lymphoma. The treatment being tested in this study is glofitamab, polatuzumab, and obinutuzumab in combination with standard treatment (the combination of rituximab, cyclophosphamide, doxorubicin, and prednisone, or R-miniCHP).