2. Patients with histologically confirmed DLBCL, including primary mediastinal large B cell lymphoma, T cell rich B cell lymphoma, "double hit" DLBCL, mantle cell lymphoma, any transformed low grade B cell lymphomas or grade 3 follicular lymphoma (Grade 3a or 3b) who were refractory to RCHOP-like or any anthracycline based chemotherapy or relapsed after at least one prior combination chemotherapeutic regimen and who are deemed candidates for a salvage type chemotherapy.